Is Early Detection of Cancer with Circulating Biomarkers Feasible_

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肝癌的类型有哪些英语作文

肝癌的类型有哪些英语作文

肝癌的类型有哪些英语作文Title: Types of Liver Cancer。

Introduction:Liver cancer is a significant health concern worldwide, with various types classified based on their origins and characteristics. Understanding these types is crucial for diagnosis, treatment, and prognosis. In this essay, we will explore the different types of liver cancer, including hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and hepatoblastoma.Main Body:1. Hepatocellular Carcinoma (HCC):HCC is the most common type of liver cancer, accounting for about 75% to 85% of cases globally.It usually develops in the hepatocytes, which are the main type of liver cells.Risk factors for HCC include chronic hepatitis B or C infection, cirrhosis, excessive alcohol consumption, obesity, and exposure to aflatoxins.Symptoms may include abdominal pain, unexplained weight loss, jaundice, and swelling in the abdomen.Diagnosis often involves imaging tests such as ultrasound, CT scan, or MRI, along with blood tests to measure liver function and tumor markers.Treatment options for HCC may include surgery, liver transplant, ablation therapy, chemotherapy, targeted therapy, and immunotherapy.2. Intrahepatic Cholangiocarcinoma (ICC):ICC originates in the bile ducts within the liver and accounts for about 10% to 20% of liver cancer cases.Risk factors for ICC include chronic inflammation of the bile ducts (such as primary sclerosing cholangitis),liver fluke infection, bile duct cysts, and certain genetic conditions.Symptoms of ICC may include jaundice, abdominal pain, itching, fever, and unexplained weight loss.Diagnosis involves imaging tests like CT scan, MRI,or endoscopic retrograde cholangiopancreatography (ERCP), along with biopsy for confirmation.Treatment options for ICC depend on the stage of the cancer and may include surgery, chemotherapy, radiation therapy, and targeted therapy.3. Hepatoblastoma:Hepatoblastoma is a rare type of liver cancer that primarily affects children under the age of 5.It originates in the embryonic liver cells and accounts for less than 1% of all childhood cancers.Risk factors for hepatoblastoma are not well understood, but certain genetic conditions, such as Beckwith-Wiedemann syndrome and familial adenomatous polyposis, may increase the risk.Symptoms of hepatoblastoma may include abdominal swelling, abdominal pain, loss of appetite, weight loss, and jaundice.Diagnosis involves imaging tests such as ultrasound, CT scan, or MRI, along with blood tests and biopsy.Treatment for hepatoblastoma typically involves surgery to remove the tumor, followed by chemotherapy. In some cases, liver transplantation may be necessary.Conclusion:In conclusion, liver cancer encompasses several types,each with its own characteristics, risk factors, and treatment options. Hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and hepatoblastoma are among the most common types, but there are other rare subtypes as well. Early detection and prompt treatment are crucial for improving outcomes and prolonging survival in patients with liver cancer. Continued research into the causes and treatments of liver cancer is essential for advancing our understanding and improving patient care.。

癌症的过度诊断英语作文

癌症的过度诊断英语作文

癌症的过度诊断英语作文Overdiagnosis of cancer has become a significant issue in modern healthcare, leading to unnecessary treatments and emotional distress for patients.The concept of overdiagnosis arises when medical tests identify conditions that would never have caused symptoms or death. In the realm of oncology, this can lead to patients undergoing aggressive treatments for cancers that might not have been life-threatening.The medical community is increasingly recognizing the importance of distinguishing between aggressive and indolent tumors. Overdiagnosis can result from the advancement of imaging technologies, which detect even the smallest of abnormalities, some of which may not require intervention.The repercussions of overdiagnosis extend beyond the physical. It can lead to a cascade of anxiety and fear, affecting the quality of life for individuals who may be living with the label of 'cancer patient' unnecessarily.To address this, a more nuanced approach to cancer detection and treatment is needed. This includes better risk stratification methods and patient education to ensure that decisions are made with full understanding of the potential benefits and harms.Moreover, the dialogue around screening programs must evolve. While early detection is crucial, it is equally important to balance this with the potential for overdiagnosis, ensuring that patients are not subjected to undue stress or treatment.In conclusion, the overdiagnosis of cancer is a complex challenge that requires a multifaceted response. By fostering a deeper understanding of the disease, refining diagnostic tools, and promoting informed decision-making, we can better navigate the delicate balance between vigilance and over-treatment.。

2023年全国医学博士英语考试真题及答案

2023年全国医学博士英语考试真题及答案

2023年全国医学博士英语考试真题及答案2023 National Medical Doctoral English Exam Questions and AnswersPart I: Reading ComprehensionRead the following passage and answer the questions that follow.Pain Management in Cancer PatientsPain is a common symptom experienced by cancer patients. Proper pain management is crucial to improving the quality of life for these patients. There are various methods for managing pain, including medications, physical therapy, and psychological interventions.Question 1: Why is pain management important for cancer patients?Question 2: What are some methods for managing pain in cancer patients?Question 3: How can physical therapy help in pain management?Question 4: What role do medications play in pain management for cancer patients?Part II: Listening ComprehensionListen to the following audio clip and answer the questions that follow.Audio Clip: A doctor discussing the importance of early detection in cancer patients.Question 1: Why is early detection important in cancer patients?Question 2: What are some common symptoms of cancer that patients should be aware of?Question 3: What screening tests are recommended for early detection of cancer?Question 4: How can lifestyle changes help in preventing cancer?Part III: WritingIn 250 words or less, write an essay on the importance of communication between healthcare providers and cancer patients. Discuss how effective communication can impact a patient's treatment and overall well-being.Part IV: SpeakingYou will be given a topic related to cancer treatment. Prepare a 3-minute speech on the topic and present it to the examiners.Answers:Part I: 1. Pain management is important for cancer patients because it helps improve the quality of life and overall well-being of the patients.2. Methods for managing pain in cancer patients include medications, physical therapy, and psychological interventions.3. Physical therapy can help in pain management by improving mobility, flexibility, and strength, which can reduce pain and discomfort in cancer patients.4. Medications play a crucial role in pain management for cancer patients by providing relief from pain and improving the patient's quality of life.Part II: 1. Early detection is important in cancer patients because it allows for timely treatment and improved outcomes.2. Common symptoms of cancer that patients should be aware of include unexplained weight loss, persistent fatigue, and changes in bowel or bladder habits.3. Screening tests recommended for early detection of cancer include mammograms, colonoscopies, and Pap smears.4. Lifestyle changes such as quitting smoking, maintaining a healthy weight, and getting regular exercise can help in preventing cancer.Part III: Effective communication between healthcare providers and cancer patients is crucial for ensuring the best possible treatment outcomes. When healthcare providers communicate effectively with their patients, they can better understand the patient's needs, concerns, and preferences, which can help tailor the treatment plan to meet the patient's individual needs. Effective communication can also help build trust between the healthcare provider and the patient, which is essential for a successful treatment relationship. Additionally, communication can help improve the patient's understanding of their condition, treatment options, and prognosis, which can reduce anxiety and fear associated with cancer diagnosis and treatment. Overall, effective communication can lead to better treatment outcomes, improved patient satisfaction, and a higher quality of life for cancer patients.Part IV: The topic of my speech is the importance of personalized treatment plans for cancer patients. Personalizedtreatment plans are essential for ensuring the best possible outcomes for cancer patients. By tailoring treatment plans to meet the individual needs, preferences, and characteristics of each patient, healthcare providers can maximize the effectiveness of treatment while minimizing side effects and complications. Personalized treatment plans can also help improve patient satisfaction, adherence to treatment, and overall quality of life. Ultimately, personalized treatment plans can lead to better treatment outcomes, improved survival rates, and a higher quality of life for cancer patients.。

癌症英语作文

癌症英语作文

Cancer is a complex group of diseases characterized by the uncontrolled growth and spread of abnormal cells.It is a significant health concern worldwide and has become a leading cause of death in many countries.Here are some key points to consider when discussing cancer in an English essay:1.Definition and Types:Begin by defining what cancer is and mentioning the various types,such as lung,breast,prostate,and colorectal cancer,which are among the most common.2.Causes:Discuss the factors that contribute to the development of cancer.These can include genetic predisposition,environmental factors,lifestyle choices,and exposure to carcinogens.3.Symptoms:Describe the common symptoms of cancer,which can vary depending on the type and stage of the disease.Early detection is crucial,and recognizing symptoms can lead to timely treatment.4.Diagnosis:Explain the methods used to diagnose cancer,such as physical examinations,imaging tests like CT scans and MRIs,and biopsies.5.Treatment Options:Cancer treatment can include surgery,chemotherapy,radiation therapy,immunotherapy,targeted therapy,and hormone therapy.Discuss the factors that influence the choice of treatment,such as the type of cancer,its stage,and the patients overall health.6.Prevention:Highlight the importance of prevention strategies,such as a healthy diet, regular exercise,avoiding tobacco smoke,limiting alcohol consumption,and getting vaccinated against certain types of cancer,like HPV and hepatitis B.7.Impact on Society:Discuss the social and economic impact of cancer,including the emotional toll on patients and their families,the cost of treatment,and the need for increased research funding.8.Advancements in Research:Mention the ongoing research and recent advancements in cancer treatment,such as personalized medicine and the development of new therapies that target specific cancer cells without harming healthy ones.9.Patient Stories:Include personal stories or testimonials to humanize the issue and illustrate the reallife effects of cancer.10.Conclusion:Conclude by summarizing the importance of awareness,early detection, and ongoing research in the fight against cancer.Encourage readers to take proactive steps to reduce their risk and support those affected by the disease.Remember to use reputable sources for your research and to cite them appropriately. Writing about cancer can be sensitive,so approach the topic with empathy and respect for those who have been affected by it.。

癌症筛查英语作文

癌症筛查英语作文

癌症筛查英语作文Title: The Importance of Cancer Screening: A Vital Step Towards Early Detection and Prevention。

Cancer screening plays a pivotal role in public health initiatives worldwide, serving as a crucial tool in the early detection and prevention of various types of cancer. Through the utilization of screening tests, healthcare professionals can identify abnormalities or early signs of cancer in individuals who may not yet show symptoms. Inthis essay, we delve into the significance of cancer screening, exploring its benefits, challenges, and the importance of widespread awareness and participation.Firstly, it is imperative to highlight the significant impact of early cancer detection on treatment outcomes and overall prognosis. Early-stage cancer detection often leads to more effective treatment options and improved survival rates. By identifying cancer in its initial stages, medical interventions such as surgery, chemotherapy, and radiationtherapy can be more successful in eradicating the disease or managing its progression. Consequently, cancer screening programs contribute to reducing cancer-related mortality rates and enhancing the quality of life for affected individuals.Moreover, cancer screening facilitates theidentification of high-risk individuals who may benefit from targeted preventive measures and lifestyle modifications. For instance, individuals with a family history of certain cancers or those exposed to specific environmental risk factors can be identified through screening programs. Subsequently, personalizedinterventions such as genetic counseling, lifestyle counseling, or chemoprevention can be implemented to mitigate the risk of developing cancer or detect it at an earlier, more treatable stage.Despite its undeniable benefits, cancer screening programs encounter several challenges that warrant attention. One such challenge is the variability in participation rates among different demographic groups andpopulations. Factors such as socioeconomic status, cultural beliefs, access to healthcare services, and fear or stigma associated with cancer diagnosis can influence anindividual's willingness to undergo screening. Addressing these disparities requires targeted outreach efforts, culturally sensitive educational campaigns, and the removal of financial and logistical barriers to screening access.Additionally, the effectiveness of cancer screening programs relies heavily on the accuracy and reliability of screening tests. While advancements in medical technology have led to the development of increasingly sensitive screening modalities, false-positive and false-negative results remain a concern. False-positive results may lead to unnecessary invasive procedures and psychological distress for individuals, while false-negative results can provide a false sense of security, delaying timely diagnosis and treatment initiation. Therefore, ongoing research and innovation aimed at enhancing the specificity and sensitivity of screening tests are essential for improving their overall efficacy.Furthermore, the success of cancer screening programs hinges on robust follow-up mechanisms and continuity of care for individuals with abnormal screening results. Timely referral to specialized healthcare providers for further diagnostic evaluation and appropriate management is paramount in ensuring that individuals receive timely and appropriate interventions. Moreover, comprehensive support services, including psychosocial support and survivorship care, are essential components of holistic cancer care that should accompany screening initiatives.In conclusion, cancer screening plays a pivotal role in early detection, prevention, and control efforts against cancer. By identifying cancer at its earliest stages, screening programs contribute to improved treatment outcomes, reduced mortality rates, and enhanced quality of life for affected individuals. However, addressing disparities in screening participation, improving the accuracy of screening tests, and ensuring seamless continuity of care are critical aspects that require ongoing attention and investment. Through collaborative efforts between healthcare providers, policymakers,advocacy groups, and the community, we can strive towards comprehensive cancer screening programs that benefit individuals and populations worldwide.。

胃癌诊断生物学标志物的研究进展

胃癌诊断生物学标志物的研究进展

·综述·胃癌诊断生物学标志物的研究进展孟文婷王蔚虹*北京大学第一医院消化内科(100034)摘要早期诊断和治疗对提高胃癌患者的生存率至关重要,但目前胃癌诊断仍依赖胃镜检查,该检查方式有创、费用较高,很难在大规模无症状人群中筛查和普及。

因此,探索无创筛查方式对早期发现胃癌至关重要。

本文概述了胃癌相关生物学标志物的前沿研究,以期早期发现胃癌,提高胃癌患者的生存率。

关键词胃肿瘤;筛查;诊断;生物学标志物Advances in Research on Biomarkers of Gastric Cancer MENG Wenting,WANG Weihong.Department ofGastroenterology,Peking University First Hospital,Beijing (100034)Correspondence to:WANG Weihong,Email:***********************AbstractEarly diagnosis and treatment of gastric cancer may improve the prognosis of the disease.At present,thediagnosis of gastric cancer depends on gastric endoscopy and histopathology,which is invasive and expensive and not suitable for screening in the large population.Non⁃invasive screening method is essential for the early detection of cancer.This article reviewed the advances in research on related biomarkers of gastric cancer so as to increase the early detection of gastric cancer and survival rate of patients.Key wordsStomach Neoplasms;Screening;Diagnosis;BiomarkersDOI :10.3969/j.issn.1008⁃7125.2023.02.007*本文通信作者,Email:***********************胃癌是目前世界上发病率较高的肿瘤之一,2020年全球胃癌新确诊病例数>100万例[1],其中中国胃癌发病例数约占世界病例数的50%[2],而胃癌预后与治疗时机息息相关,早期诊断和治疗对提高胃癌患者的生存率至关重要。

斑马鱼心血管疾病模型研究进展

斑马鱼心血管疾病模型研究进展

·综述·斑马鱼心血管疾病模型研究进展董顺雨 张 态大理大学公共卫生学院(云南大理 671000)【摘 要】 心血管疾病是导致我国居民死亡的首要原因。

在2006—2019年间,我国每年因心血管疾病死亡的人数从215万人增加到328万人。

斑马鱼因个体小、成本低廉、体外发育、身体透明、基因组与人类高度同源等特点,近年来被广泛应用于医学研究。

斑马鱼模型有利于推动心血管疾病领域的基础性研究。

该文通过对前期研究进行综述,重点介绍了斑马鱼模型在心血管疾病中基因筛选、心脏再生、药物筛选、毒性评估等方面的研究进展。

【关键词】 斑马鱼;心血管疾病;心脏再生;药物筛选;毒性评估DOI :10. 3969 / j. issn. 1000-8535. 2024. 03. 003Research progress of zebrafish cardiovascular disease modelsDONG Shunyu ,ZHANG TaiSchool of Public Health ,Dali University ,Dali 671000,China【Abstract 】 Cardiovascular disease is the leading cause of death in China .Between 2006 and 2019,the annual number of deaths due to cardiovascular diseases increased from 2.15 million to 3.28 million .Zebrafish has been widely used in medical research in recent years because of its small individual size ,low cost ,in vitro development ,transparent body and high homology of genome with human .The zebrafish model is conducive to promoting basic research in the field of cardiovascular disease .Based on the review of previous studies ,this paper focuses on the research progress of zebrafish model in gene screening ,cardiac regeneration ,drug screening ,toxicity assessment and other aspects of cardiovascular diseases .【Key words 】 zebrafish ;cardiovascular disease ;heart regeneration ;drug screening ;toxicity assessment基金项目:中国西南药用昆虫及蛛形类资源开发利用协同创新中心(CIC1803)通信作者:张态,E-mail:******************心血管疾病是全球的主要死亡原因,是由环境因素和遗传因素共同导致的一种疾病[1]。

累及心脏及肾脏Fabry病一例

累及心脏及肾脏Fabry病一例

D0I:10.3969/j .issn.1005-8001.2021.03.011 作者单位:210029江苏南京,南京医科大学第一附属医院放射科(薛秋苍、徐怡),病理科(刘冲),肾内科(卞奥、毛慧娟) 通信作者:徐怡,Email: yixu@
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影像诊断与介入放射学2021年第30卷第3期
structural changes in patients with Fabry's disease. Am Heart
J, 2000,139:1101-1108. [愿]苏瑾,朱永胜,罗秀霞,等.心脏磁共振和超声诊断肥厚性
心肌病的价值.影像诊断与介入放射学,2020,29:167-170.
[9 ] Fontana M, Banypersad SM, Treibel TA, et al. Native T1
肾脏病理结果:光镜下见弥漫肾小管上皮细胞泡沫样
变、灶性小管上皮细胞颗粒样变性(图2),免疫荧光IgM 示系膜区节段性块状(++),主要诊断:Fabry病可能,建议 结合基因检测结果。
基因检测:编码a半乳糖苷酶A的基因(GLA)有一个半 合子突变:c.974G>A突变,染色体位置:chrX:100653383 , 氨基酸变化为p.G325D,为错义突变,根据ACMG指南,该变 异初步判定为致病性变异PS4+PM1+PM2+PM5+PP3+PP4。
classical and nonclassical Fabry disease: a multicenter study. J
Am Soc Nephrol, 2017,28:1631-1641.
[4] NiemannM, Herrmann S, Hu K, et al. Differences in Fabry

癌症的过度诊断英语作文

癌症的过度诊断英语作文

癌症的过度诊断英语作文In recent years, the issue of cancer overdiagnosis has become a significant concern in the medical community. Overdiagnosis occurs when a cancer is diagnosed that would not have caused any symptoms or harm during a person's lifetime. While early detection of cancer is crucial for effective treatment, overdiagnosis can lead to unnecessary stress, invasive treatments, and healthcare costs.One of the primary reasons for cancer overdiagnosis is the increased use of advanced screening technologies, such as mammograms for breast cancer and PSA tests for prostate cancer. These screenings have improved our ability to detect cancer at earlier stages; however, they also lead to the identification of slow-growing tumors that may never progress to a life-threatening stage. This is particularly evident in prostate cancer, where many men diagnosed may not require immediate treatment.The psychological impact of overdiagnosis should not be underestimated. Patients who receive a cancer diagnosis often experience anxiety and fear, even iftheir cancer is not aggressive. The label of "cancer" can lead to emotional distress and a diminished quality of life. Furthermore, the treatments for cancer, such as surgery, radiation, or chemotherapy, can have significant side effects and may not be necessary for patients with non-aggressive tumors.To address the issue of overdiagnosis, it is essential to promote informed decision-making among patients and healthcare providers. Patients should be educated about the risks and benefits of cancer screenings, as well as the possibility of overdiagnosis. Healthcare providers must engage in shared decision-making, considering the individual patient's values and preferences when recommending screenings and treatments.In conclusion, while early detection of cancer is vital, we must be cautious about the risks of overdiagnosis. By fostering awareness and encouraging informed choices, we can help patients avoid unnecessary treatments and improve their overall well-being.中文翻译:近年来,癌症过度诊断的问题在医学界引起了广泛关注。

癌症筛查和癌症过度诊断的相关英语作文

癌症筛查和癌症过度诊断的相关英语作文

癌症筛查和癌症过度诊断的相关英语作文全文共3篇示例,供读者参考篇1Cancer screening and overdiagnosis of cancer are two important topics in the field of oncology. Cancer screening aims to detect cancer at an early stage when it is more likely to be treated successfully, while overdiagnosis refers to the detection and treatment of cancers that would not have caused harm if left untreated.There are several methods for cancer screening, including mammograms for breast cancer, colonoscopies for colorectal cancer, and PSA tests for prostate cancer. While these screenings have the potential to save lives by detecting cancer at an early stage, they also have the risk of overdiagnosis. Overdiagnosis can lead to unnecessary treatment, which can have serious consequences for patients, including unnecessary surgery, radiation, and chemotherapy.One of the biggest challenges in cancer screening is finding the right balance between detecting cancers early and avoiding overdiagnosis. This requires careful consideration of the benefitsand risks of screening, as well as a clear understanding of the limitations of screening tests. It is also important for healthcare providers to communicate effectively with patients about the potential risks and benefits of screening and to involve patients in decision-making about their healthcare.In recent years, there has been increasing recognition of the problem of overdiagnosis in cancer screening. Some experts argue that the focus should shift from early detection of cancer to more personalized approaches that take into account a patient's individual risk factors and preferences. This may involve using new technologies, such as genetic testing, to identify individuals who are at higher risk of developing cancer and tailoring screening recommendations accordingly.In conclusion, cancer screening is an important tool for detecting cancer early and improving patient outcomes. However, it is also important to be aware of the risks of overdiagnosis and to take a balanced approach to screening that considers both the benefits and harms. By taking a personalized approach to screening and involving patients in decision-making, we can ensure that screening programs are effective and safe for all individuals.篇2Cancer Screening and Overdiagnosis in CancerIntroductionCancer is one of the leading causes of death worldwide, and early detection through cancer screening has been widely promoted as a means of reducing cancer mortality. However, there is growing concern about the issue of overdiagnosis in cancer screening, where individuals are diagnosed with cancers that would never have caused symptoms or harm during their lifetime. This essay will discuss the importance of cancer screening, the challenges associated with overdiagnosis, and potential solutions to address this issue.The Importance of Cancer ScreeningCancer screening aims to detect cancer in its early stages when treatment is more likely to be successful. Screening tests can detect cancer before symptoms develop, increasing the likelihood of successful treatment and survival. Examples of cancer screening tests include mammograms for breast cancer, colonoscopies for colorectal cancer, and Pap smears for cervical cancer. These screening tests have been shown to reduce cancer mortality and improve outcomes for patients when cancers are detected and treated early.Challenges of Overdiagnosis in Cancer ScreeningDespite the benefits of cancer screening, overdiagnosis is a significant concern. Overdiagnosis occurs when screening detects cancers that would never have caused harm, leading to unnecessary treatments that can have negative side effects. Overdiagnosis can result in unnecessary stress, anxiety, and financial burden for patients who receive unnecessary treatment. In addition, overdiagnosis can lead to overtreatment, where patients are treated for cancers that would never have caused symptoms or harm.Potential Solutions to Address OverdiagnosisAddressing overdiagnosis in cancer screening requires a multifaceted approach. Healthcare providers can improve the informed consent process for cancer screening, providing patients with accurate information about the risks and benefits of screening. In addition, guidelines for cancer screening can be revised to reduce unnecessary testing and follow-up procedures for low-risk individuals. Healthcare providers can also implement shared decision-making strategies to involve patients in the decision-making process about cancer screening.ConclusionCancer screening plays a crucial role in early detection and treatment of cancer, leading to improved outcomes for patients. However, overdiagnosis is a significant challenge that must be addressed to ensure that individuals receive appropriate care without unnecessary harm. By implementing strategies to reduce overdiagnosis, healthcare providers can improve the effectiveness and impact of cancer screening programs.篇3Cancer Screening and Overdiagnosis of CancerIntroductionCancer screening is crucial in early detection and prevention of cancer. It involves testing individuals for cancer before they show any symptoms. Screening tests are conducted with the aim of identifying cancer at an early stage when treatment is most effective. However, there are concerns about overdiagnosis in cancer screening, which can result in unnecessary treatments and interventions for individuals who may not have actually developed cancer. This essay explores the benefits of cancer screening, the concept of overdiagnosis in cancer, and strategies to mitigate its impact.Benefits of Cancer ScreeningCancer screening has numerous benefits in the early detection and prevention of cancer. It can help detect cancer at an early stage when it is most treatable and has a higher chance of cure. Screening tests can also identify precancerous lesions, allowing for early intervention to prevent the development of cancer. Moreover, cancer screening can reduce cancer-related mortality by detecting cancer early and enabling timely treatment. Overall, cancer screening plays a crucial role in improving outcomes for individuals at risk of developing cancer.Overdiagnosis in Cancer ScreeningOverdiagnosis refers to the detection of cancers that would never have caused symptoms or affected an individual's health. In cancer screening, overdiagnosis can result in unnecessary treatments, psychological distress for individuals, and burdens on the healthcare system. Overdiagnosis can occur due to advancements in screening technologies, increased awareness and uptake of cancer screening, and the detection of indolent or slow-growing cancers that may never progress to a clinically significant stage. It is essential to address the issue of overdiagnosis in cancer screening to ensure that individuals receive appropriate and necessary care without unnecessary harm.Strategies to Mitigate OverdiagnosisThere are several strategies to mitigate the impact of overdiagnosis in cancer screening. One approach is to develop more specific and sensitive screening tests that can distinguish between indolent and aggressive cancers. By improving the accuracy of screening tests, healthcare providers can reduce the likelihood of overdiagnosis and unnecessary treatments. Another strategy is to enhance risk stratification algorithms to identify individuals who are at higher risk of developing aggressive cancers and may benefit from screening. By tailoring screening recommendations to individual risk profiles, healthcare providers can optimize the benefits of screening while minimizing overdiagnosis. Additionally, educating healthcare providers and the public about the concept of overdiagnosis and the potential harms of unnecessary treatments can help raise awareness and facilitate shared decision-making in cancer screening.ConclusionIn conclusion, cancer screening is a valuable tool in early detection and prevention of cancer. However, overdiagnosis is a potential challenge that can lead to unnecessary treatments and interventions for individuals who may not have actuallydeveloped cancer. It is essential to understand the concept of overdiagnosis, its implications, and strategies to mitigate its impact in cancer screening. By developing more specific screening tests, enhancing risk stratification algorithms, and raising awareness among healthcare providers and the public, we can improve the effectiveness of cancer screening while minimizing the risks of overdiagnosis. Ultimately, a balanced approach that considers the benefits and potential harms of cancer screening is essential in promoting optimal health outcomes for individuals at risk of developing cancer.。

肿瘤的真相与坏处英语作文

肿瘤的真相与坏处英语作文

Cancer. The word alone sends a shiver down the spine of many. Its a disease that has touched the lives of countless individuals, leaving a trail of devastation in its wake. Yet, despite its prevalence, there remains a great deal of misunderstanding and fear surrounding it. In this essay, I aim to shed light on the truth about cancer and discuss its detrimental effects on both a personal and societal level.Growing up, I was always aware of cancer, but it wasnt until I lost my beloved uncle to this insidious disease that I truly understood its impact. My uncle was a vibrant, energetic man who loved life and lived it to the fullest. His diagnosis came as a shock to our entire family, and the subsequent battle he fought was nothing short of heroic.Cancer is a complex group of diseases characterized by the uncontrolled growth and spread of abnormal cells. There are over 100 different types of cancer, ranging from common ones like breast and lung cancer to rarer forms like mesothelioma. Whats often overlooked, however, is that not all cancers are the same. Some are more aggressive than others, and the treatment options and prognoses can vary greatly.One of the most significant challenges with cancer is early detection. Many forms of the disease can be asymptomatic in their early stages, making it difficult to diagnose until it has progressed to a more advanced stage. This is where regular screenings and checkups become crucial. The earlier cancer is detected, the higher the chances of successful treatment and survival.But cancer is not just a physical battle its also an emotional and psychological one. The fear, uncertainty, and anxiety that come with a cancer diagnosis can be overwhelming. Patients often grapple with feelings of isolation, depression, and a loss of control over their lives. This is where the importance of a strong support system comes into play. Family, friends, and healthcare professionals can provide invaluable emotional support and help patients navigate the complex journey of cancer treatment.The financial burden of cancer treatment is another aspect that cannot be ignored. The costs associated with diagnosis, treatment, and ongoing care can be astronomical, often leading to significant financial strain for patients and their families. This is particularly true for those without adequate health insurance coverage. The financial toxicity of cancer treatment is a real and pressing issue that needs to be addressed.On a societal level, cancer has farreaching implications. It affects not only the individuals diagnosed but also their families, friends, and communities. The loss of a loved one to cancer can leave a lasting impact, altering the dynamics of relationships and the emotional wellbeing of those left behind. Moreover, the economic burden of cancer on healthcare systems is immense, with resources being diverted to manage this disease.Despite the challenges, there is hope. Advances in medical research have led to significant improvements in cancer treatment and survival rates. New therapies, such as immunotherapy and targeted treatments, are offering more personalized and effective options for patients. Additionally,increased awareness and education about cancer prevention, early detection, and healthy lifestyle choices are playing a crucial role in reducing the incidence of this disease.In conclusion, cancer is a complex and multifaceted disease that affects individuals and societies in profound ways. While it brings with it a myriad of challenges, from physical and emotional struggles to financial burdens, it also serves as a reminder of the resilience of the human spirit. As we continue to make strides in research and treatment, its essential to support those affected by cancer and work towards a future where this disease is no longer a death sentence.。

癌症筛查和癌症过度诊断的英语作文

癌症筛查和癌症过度诊断的英语作文

癌症筛查和癌症过度诊断的英语作文Title: Cancer Screening and the Dilemma of OverdiagnosisIn the modern era of healthcare, cancer screening has become a crucial tool in the early detection of malignancies, enabling prompt treatment and often improving patient outcomes. However, the increasing reliance on screening methods has also led to a controversial issue known as cancer overdiagnosis.Cancer screening refers to the use of various tests and procedures to detect cancer in its early stages, often before symptoms appear. These screening methods range from simple physical examinations to complex imaging techniques and biomarker tests. Breast cancer screening with mammograms, colon cancer screening with colonoscopies, and prostate cancer screening with PSA tests are some common examples. The benefits of early detection are numerous, including increased treatment options, improved survival rates, and a reduced need for aggressive therapies.However, the rise of cancer screening has also brought about the challenge of overdiagnosis. Overdiagnosis refers to the identification of a cancer that would not have caused harm if it had not been detected and treated. This can occur when screening tests detect small or slow-growing tumors that may never progress to causesymptoms or threaten a patient's life. The resulting overdiagnosis often leads to unnecessary treatments, such as surgery, radiation, or chemotherapy, which can have significant physical and psychological impacts on patients.The dilemma of overdiagnosis is particularly relevant in the context of breast cancer screening. While mammograms have been instrumental in reducing breast cancer mortality, they also have a relatively high false-positive rate. This means that many women are subjected to unnecessary further testing, including biopsies, which can be physically and emotionally distressing. Moreover, some of these women may be diagnosed with cancers that would never have threatened their lives.The issue of overdiagnosis is not limited to breast cancer screening alone. Other screening modalities, such as low-dose computed tomography (LDCT) for lung cancer and prostate-specific antigen (PSA) testing for prostate cancer, also have the potential for overdiagnosis. The key to addressing this dilemma lies in the judicious use of screening tests and a balanced approach to cancer detection and treatment.In conclusion, cancer screening is an invaluable tool in the fight against cancer, but it must be used wisely to avoid the pitfalls of overdiagnosis. Healthcare providers and policymakers must worktogether to develop screening programs that are effective, efficient, and tailored to the needs of individual patients. By doing so, we can ensure that cancer screening remains a force for good in the fight against this devastating disease.。

癌症筛查和癌症过度诊断的英语作文

癌症筛查和癌症过度诊断的英语作文

Cancer Screening and the Risk ofOverdiagnosisIn recent years, cancer screening has become increasingly common, with the aim of detecting tumours early, often before symptoms manifest. However, this risein screening has led to concerns about cancer overdiagnosis—the detection of tumours that may never cause harm or even exist at all.Cancer screening involves tests designed to identify tumours in their earliest stages, when they are most treatable. This can include mammography for breast cancer, colonoscopy for colorectal cancer, and Pap smears for cervical cancer. While these tests have the potential to save lives, they are not perfect. False positives—results that suggest cancer is present when it is not—can lead to unnecessary biopsies, surgeries, and anxiety for patients. Moreover, some tumours grow slowly and may never progress to cause symptoms or death. These tumours are known as indolent tumours, and their detection through screening can lead to overdiagnosis. Overdiagnosis occurs when a tumour is detected and treated, but the tumour wouldnever have caused harm to the patient had it been left untreated.The risk of overdiagnosis is particularly high in cancers that are common and slow-growing, such as prostate cancer and thyroid cancer. In these cases, the harm caused by treatment—which can include side effects like incontinence and hypothyroidism—may outweigh the benefits of early detection.To mitigate the risk of overdiagnosis, it is important to consider the balance between the benefits and risks of screening. This means being informed about the potential for false positives and understanding the natural history of the cancer being screened for. It also involves discussions with healthcare providers about personal risk factors, family history, and the potential impact of treatment on quality of life.In conclusion, while cancer screening can save lives, it is crucial to be aware of the risk of overdiagnosis. By understanding the limitations of screening tests and discussing personal risks with healthcare providers,patients can make informed decisions about whether screening is right for them.**癌症筛查与过度诊断的风险**近年来,癌症筛查变得越来越普遍,其目的在于在症状出现之前尽早发现肿瘤。

癌症筛查英语作文初中

癌症筛查英语作文初中

癌症筛查英语作文初中题目,Cancer Screening。

Introduction。

Cancer screening is a crucial aspect of healthcare, aimed at detecting cancer in its early stages when it's more treatable. It involves various tests and procedures designed to identify cancer before any symptoms appear. The importance of cancer screening cannot be overstated, as early detection significantly increases the chances of successful treatment and survival. In this essay, we will delve into the significance of cancer screening and explore some common methods used for early detection.Importance of Cancer Screening。

Early detection through screening plays a pivotal role in reducing cancer-related mortality rates. Many types of cancer, such as breast, cervical, colorectal, and prostatecancer, can be detected at an early stage through routine screening tests. When cancer is diagnosed early, treatment options are often less invasive and more effective, leading to better outcomes for patients. Furthermore, screening can help identify precancerous conditions, allowing for preventive measures to be taken before cancer develops.Common Screening Methods。

基于NRU网络的肺结节检测方法

基于NRU网络的肺结节检测方法

2021574肺癌作为人类健康和生命威胁最大的恶性肿瘤之一[1],在我国的发病率和死亡率增长最快。

早期诊断是提高患者生存率的关键[2],但是由于肺结节的直径小,早期的肺癌结节很难检测到。

计算机断层扫描(CT)与其他医学诊断技术相比具有更高的准确性,因此被广泛用于检测肺结节。

检查CT会花费医生的大量时间和精力,并且医生的诊断水平不一致,因此很容易出现误诊。

为了提高诊断的准确性,目前已有计算机辅助诊断(CAD)系统来辅助肺癌检测[3-4]。

医生可以将结果作为判断的参考,这项技术加快了检测速度,并在一定程度上降低了误诊率[5]。

肺癌的自动检测过程分为两个步骤:(1)提取所有可疑候选结节;(2)将提取的结节分为两类(阳性和假阳性结节)。

第二步中的分类对象来自第一步中的识别结基于NRU网络的肺结节检测方法徐麒皓,李波武汉科技大学计算机科学与技术学院,武汉430081摘要:肺癌的早期发现和早期诊断是提高肺癌患者生存率的关键。

由于肺癌早期结节很小,目前已有的肺结节检测系统在检测这些结节时很容易漏诊。

准确检测早期肺癌结节对于提高肺癌治愈率至关重要,为了降低检测系统对早期结节的漏诊率,需要优化候选结节的提取步骤。

在U-Net网络中引入残差网络的捷径,有效解决了传统U-Net 网络由于缺乏深度而导致结果较差的问题。

在此改进的基础上提出了一种U型噪声残差网络NRU(Noisy Residual U-Net),通过利用跳跃层连接的特性和向卷积层添加噪声来增强神经网络对小结节的灵敏度。

使用Lung Nodule Analysis2016和阿里巴巴天池肺癌检测竞赛数据集训练神经网络。

U-Net和NRU之间的比较实验表明,该算法对直径为3~5mm(97.1%)的小结节的灵敏度大于U-Net值(90.5%)。

关键词:肺癌;肺结节;肺结节检测系统;噪声;残差网络文献标志码:A中图分类号:TP391.41doi:10.3778/j.issn.1002-8331.1911-0216Method for Detecting Pulmonary Nodules Based on NRU NetworkXU Qihao,LI BoSchool of Computer Science and Technology,Wuhan University of Science and Technology,Wuhan430081,ChinaAbstract:The early detection and diagnosis of lung cancer is the key to improve the survival rate of lung cancer patients. Due to the small nodules in the early stage of lung cancer,the existing pulmonary nodules detection system is easy to miss the diagnosis when detecting these nodules.Accurate detection of early lung nodules is crucial to improve the cure rate of lung cancer.In order to reduce the missed rate of early nodules in the detection system,it is necessary to optimize the extrac-tion procedure of candidate nodules.The shortcut of residual network is introduced into U-Net,which effectively solves the disadvantage of poor results caused by the lack of depth in the traditional U-Net.On the basis of this improvement,a U-type noise residual network NRU(Noisy Residual U-Net)is proposed to enhance the sensitivity of neural network to small nodules by using the characteristics of hopping layer connection and adding noise to the convolutional layer.The Lung Nodule Analysis2016and Alibaba Tianchi lung cancer detection competition data sets are used to train the neural parison experiments between U-Net and NRU show that the sensitivity of the algorithm to small nodules with a diameter of3-5mm(97.1%)is greater than that of U-Net(90.5%).Key words:lung cancer;pulmonary nodules;pulmonary nodules detection system;noise;residual network⦾模式识别与人工智能⦾基金项目:国家自然科学基金(61572381)。

癌症的过度诊断英文作文

癌症的过度诊断英文作文

癌症的过度诊断英文作文Cancer overdiagnosis refers to the identification of a cancer that would not have caused harm if it had not been detected and treated. This can lead to unnecessary treatments and psychological distress for patients. Overdiagnosis can occur through the use of screening tests, which can identify small or slow-growing tumors that may never cause symptoms or harm. As a result, patients may undergo invasive treatments such as surgery, radiation, or chemotherapy that they may not have needed.There are several reasons why cancer overdiagnosis occurs. Firstly, advances in medical technology and imaging have led to the increased detection of small tumors that may not have been found in the past. Additionally, there is pressure on healthcare providers to identify and treat cancer early in order to improve patient outcomes, which can lead to the overuse of screening tests. Finally, there is a lack of understanding about the natural history of cancer, which makes it difficult to distinguish between harmless and potentially harmful tumors.Overdiagnosis of cancer can have serious consequencesfor patients. Not only can it lead to unnecessary treatments and their associated side effects, but it can also cause psychological distress and anxiety. Patients may experience fear and uncertainty about their diagnosis, and may struggle to make decisions about their treatment options. Furthermore, overdiagnosis can lead to increased healthcare costs and the overutilization of resources, which can strain healthcare systems.To address the issue of cancer overdiagnosis, it is important for healthcare providers to carefully consider the potential harms and benefits of screening tests. Patients should be informed about the risks of overdiagnosis and the potential consequences of unnecessary treatment. Additionally, more research is needed to better understand the natural history of cancer and to develop more accurate diagnostic tools.癌症的过度诊断是指发现了本来如果没有被发现和治疗就不会对人体造成伤害的癌症。

癌症的过度诊断英文作文

癌症的过度诊断英文作文

癌症的过度诊断英文作文The Issue of Overdiagnosis of Cancer.Cancer, a term that strikes fear into the hearts of many, has become a focal point of medical research and attention worldwide. However, recent studies have raised concerns about the issue of overdiagnosis, a phenomenon where cancer is detected and treated, but may never have caused symptoms or resulted in harm to the patient. This essay delves into the complexities of overdiagnosis, its causes, impact, and potential solutions.Causes of Overdiagnosis.The root of the problem lies in the advancements in medical technology, particularly diagnostic tools like imaging scans and genetic testing. These technologies have become increasingly sensitive, allowing doctors to detect minute abnormalities that may never progress intoclinically significant disease. Additionally, thewidespread availability of these tests and the pressure to screen for diseases have led to a surge in the number of cancer diagnoses.Impact of Overdiagnosis.The impact of overdiagnosis is profound and far-reaching. Firstly, it can lead to unnecessary treatments, including surgeries, radiation, and chemotherapy, all of which have their own associated risks and side effects. These treatments can take a toll on the physical and mental health of patients, affecting their quality of life.Moreover, overdiagnosis can lead to overtreatment, which not only fails to improve patient outcomes but can also be harmful. For instance, some cancers grow slowly and may never cause symptoms or require treatment. Treating these indolent cancers can expose patients to the risks of treatment without offering any benefit.The Challenges of Overdiagnosis.Diagnosing cancer accurately is challenging, as it requires a balance between detecting diseases early enough for effective treatment and avoiding false positives that lead to overdiagnosis. The complexity of cancer biology and the variability in tumor behavior further complicate the issue.Furthermore, the financial incentives within the healthcare system can also contribute to overdiagnosis. In some cases, doctors and hospitals may be motivated to diagnose and treat more patients due to the associated revenue. This can lead to a culture of overtesting and overtreatment, even when it is not medically necessary.Potential Solutions.Addressing overdiagnosis requires a multi-faceted approach. Firstly, education and awareness among healthcare providers and the public is crucial. Doctors need to be trained to interpret diagnostic tests accurately and understand the limitations of technology. Patients should also be informed about the risks and benefits of varioustests and treatments, enabling them to make informed decisions about their healthcare.Secondly, there is a need for more research on cancer biology and the natural history of tumors. This will help doctors understand which tumors are likely to progress and require treatment, and which ones are indolent and can be safely monitored.Thirdly, the healthcare system needs to reform its financial incentives to reduce the pressure for overtesting and overtreatment. This could involve changes in reimbursement policies and the introduction of quality metrics that reward providers for accurate diagnoses and effective treatments.In conclusion, overdiagnosis of cancer is a complex issue that requires a concerted effort from all stakeholders in the healthcare system. By educating ourselves, promoting research, and reforming financial incentives, we can hope to reduce the harm caused by overdiagnosis and improve patient outcomes.。

妇科英语试题库及答案

妇科英语试题库及答案

妇科英语试题库及答案一、选择题1. Which of the following is NOT a common gynecological symptom?A. Abnormal vaginal bleedingB. Pelvic painC. Frequent urinationD. High blood pressure2. What is the medical term for the surgical removal of the uterus?A. HysterectomyB. OophorectomyC. SalpingectomyD. Cystoscopy3. Which hormone is primarily responsible for the development of female reproductive organs?A. EstrogenB. ProgesteroneC. TestosteroneD. Insulin4. What is the most common type of ovarian cancer?A. EndometrioidB. MucinousC. SerousD. Clear cell5. Which of the following is a risk factor for endometrial cancer?A. Early menarcheB. Late menopauseC. ObesityD. All of the above二、填空题6. The term for the monthly cycle of changes in the female reproductive system is __________.7. A condition where the uterus is displaced from its normal position is called __________.8. The medical condition characterized by the presence of endometrial-like tissue outside the uterus is known as__________.9. The process of monitoring the development of a fetus in the womb is called __________.10. A surgical procedure to remove a fibroid from the uterus is known as __________.三、简答题11. Briefly describe the purpose of a Pap smear test.12. What are the common symptoms of polycystic ovary syndrome (PCOS)?13. Explain the difference between primary and secondary dysmenorrhea.四、案例分析题14. A 35-year-old woman presents with a history of irregular periods and heavy menstrual bleeding. She also reportsexperiencing severe cramps during her periods. Whatconditions should be considered in the differential diagnosis?五、翻译题15. Translate the following sentence into English:“子宫内膜异位症是一种常见的妇科疾病,影响许多育龄妇女。

循环肿瘤细胞检测在晚期肿瘤患者维持治疗中的应用

循环肿瘤细胞检测在晚期肿瘤患者维持治疗中的应用

循环肿瘤细胞检测在晚期肿瘤患者维持治疗中的应用连洁;杨宇【摘要】循环肿瘤细胞(CTC)检测敏感性和特异性较高,且创伤小、取材方便,具有可重复性,其在肿瘤早期诊断、临床分期、指导治疗及预测预后等方面的优势已得到临床认可,但CTC作为维持治疗疗效判定指征的意义尚未明确.本文针对CTC提取分离、检测方法、临床应用以及维持治疗期间检测的意义予以综述.%Circulating tumor cells(CTC)detection, due to its good sensitivity and specificity, less trauma, convenience and repeatability of obtaining materials, has gained clinical consensus for its advantages in early diagnosis, clinical staging, guiding treatment and predicting prognosis.However,it still remains unclear that the significance of CTC as an indicator for maintenance therapy. In this paper,we reviewed the extraction,isolation,detection and clinical application of CTC,and its value in maintenance therapy.【期刊名称】《中华老年多器官疾病杂志》【年(卷),期】2018(017)005【总页数】3页(P394-396)【关键词】维持治疗;循环肿瘤细胞;晚期肿瘤【作者】连洁;杨宇【作者单位】哈尔滨医科大学附属第二医院肿瘤内科,哈尔滨150001;哈尔滨医科大学附属第二医院肿瘤内科,哈尔滨150001【正文语种】中文【中图分类】R730.5近年来,恶性肿瘤的发病率和死亡率呈逐年上升的趋势,成为威胁人类生命的重要原因之一。

胃癌患者血液中播散的肿瘤细胞是预后不良的一个独立的预测标志物

胃癌患者血液中播散的肿瘤细胞是预后不良的一个独立的预测标志物

胃癌患者血液中播散的肿瘤细胞是预后不良的一个独立的预测标志物Illert B.;Fein M.;Otto C.;樊菁【期刊名称】《世界核心医学期刊文摘:胃肠病学分册》【年(卷),期】2005(000)012【摘要】Objective. Gastric cancer carries a poor prognosis even after curative resection (RO). Tumor progression in gastric cancer patients has been attributed to the persistence of disseminated tumor cells (DTC) in various body compartments as a sign of minimal residual disease, although the prognostic relevance of DTC is still unclear. In this study the prognostic relevance of DTC in the blood of gastric cancer patients was investigated. Material and methods. Venous blood samples of 70 cancer patients were taken intraoperatively before surgical manipulation and examined by reverse transcription- polymerase chain reaction (RT- PCR) for expression of cytokeratin 20 (CK20) as a marker for DTC. Tumor- related survival was analyzed using univariate and multivariate models assessing occurrence of DTC, residual tumor classification, and tumor stage. Median follow- up was 20 months (range 1- 57 months). Results. Twenty- eight of the 70 patients (40% )were CK20 positive. The prevalence of DTC in patients following RO resection (15/41, 37% ) was similar to that in patients with residual tumor (13/29, 45% , NS). Furthermore, expression of CK20 was independent of TNM stage. Univariate analysis of R0-resected patients revealed CK20 to be a marker for significantly shorter tumorrelated survival (p = 0.0363). In a multivariate analysis, CK20 was an independent prognostic marker. Detection of CK20 had greatest impact for early tumor stages (T1 and T2, N0; p < 0.0032). Conclusions. Detection of DTC in venous blood of gastric cancer patients is an independent predictive marker of poor prognosis and thus could help to define patients for adjuvant therapy with this tumor entity.【总页数】1页(P54-54)【作者】Illert B.;Fein M.;Otto C.;樊菁【作者单位】hirurgische Klinik I Zentrum Operative Medizin Oberdü rrba- cher Str. 6 DE- 97080Würzburg Germany Dr.【正文语种】中文【中图分类】R735.2【相关文献】1.胰腺癌播散肿瘤细胞的检测及其对预后的影响 [J], 徐晓蓉;李兆申2.根治术前后肿瘤细胞在骨髓中播散的自动显微图像研究 [J], 黄瑜峰;刘立义;RiesenbergR;ObernederR;BuchnerA;HofstetterA3.循环肿瘤细胞和播散肿瘤细胞对食管癌患者预后的meta分析 [J], 石晓欣;安建虹;黄业恩;张耀忠;黄卓雅;邹振宁;陈清;申洪4.喉癌动物模型中播散肿瘤细胞与突变型p53的研究 [J], 左汶奇;胡国华;李忠万;张园园;蒋建国5.胃癌患者术后预后的独立危险因素及淋巴结转移率对不同pN分期胃癌患者预后的影响 [J], 余协媛;徐永灿;汪伟民因版权原因,仅展示原文概要,查看原文内容请购买。

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Bob Barrett: This is the podcast from Clinical Chemistry. I am BobBarrett.Early cancer detection before metastasis inasymptomatic patients is one of the primaryobjectives of cancer research initiatives. Earlydetection generally means more opportunities forintervention that ultimately lead to improvements inpatient outcomes.The January 2013 issue of Clinical Chemistry isdevoted to the area of cancer and cancer diagnostics.Joining us in this podcast is Dr. Danijela Konforte,author of a perspective article, asking if earlydetection of cancer with circulating biomarkers isfeasible.Dr. Konforte is a graduate of the postdoctoraldiploma program in Clinical Chemistry at theUniversity of Toronto, and is currently a clinicalbiochemist at LifeLabs, a community laboratory inToronto.Doctor, many blood-based cancer biomarkers arecommonly used in clinical practice for riskstratification, prognosis, surveillance, and formonitoring therapy, but effective blood-basedbiomarkers for early diagnosis of cancer, those arelacking. Why are biomarkers for early detection ofcancer so important?Dr. Danijela Konforte: Well, detecting any disease early, including cancer, isvery important because it usually means moreopportunities for different interventions andtherapies, with increased potential for improvingpatient survival and quality of life.For instance, there are many studies that haveshown that early detection of breast cancer in womenover 50 years of age with annual mammogramscreening programs, improved survival by about 20-25%.Also patients at stage one ovarian cancer detected bytransvaginal ultrasound, have a five-year survivalrate of about 93% compared to only 30% forpatients with stage 3 to stage 4 disease at diagnosis.Some other examples of cancer screening proceduresand biomarkers that have considerably improvedpatient outcomes, include Pap tests and nowmolecular tests for cervical cancer, colonoscopy,sigmoidoscopy, and fecal occult blood test for coloncancer, blood human chorionic gonadotropin or hCGfor testicular cancer and for gestational trophoblasticdisease, and also blood alpha-fetoprotein or AFP inthose people who are at high risk of developinghepatocellular carcinoma.Bob Barrett: What criteria should a circulating biomarker for earlydetection of cancer fulfill?Dr. Danijela Konforte: As you mentioned in your introduction, Bob, only afew tumor biomarkers in clinical use are suitable forpopulation screening and for early diagnosis.So a biomarker test for early detection of cancershould be sufficiently sensitive and specific, and hereI refer to both diagnostic and analytical sensitivityand specificity. Also it should be relativelyinexpensive and safe to be applied to masspopulations. It should also be relatively non-invasiveand provide sufficient lead time.A lead time is the time interval from screen detectedcancer to clinical diagnosis in the absence of suchscreening. So in other words it is the time betweenasymptomatic disease and metastasis. The lead timefor early cancer detection using a blood biomarkerdepends on the growth trajectory of a cancer.An aggressive tumor will have a significantly shorterlead time than a slow progressing tumor. Usuallyimproved lead time means more effectiveinterventions which leads to improved diseaseoutcomes and improved survival.Another important requirement for bringing blood -based biomarker into routine clinical use isdeveloping a high throughput, easy-to-use laboratorytest to reproducibly and accurately measure suchbiomarker.In addition to these requirements, clinical benefitsprovided by the tumor marker should clearlyoutweigh any potential harm. Two examples are overdiagnosis and over treatments of indolent cancersthat will not lead to symptoms or cause death.Another potential harm is the lead time bias, and thisrefers to early diagnosis of a cancer that does notlead to improved survival.One good example of a blood biomarker for earlycancer detection whose benefits and harms are stillhotly debated is Prostate Specific Antigen or PSA.There is still not sufficient evidence to definitelyanswer the question of whether early detection ofprostate cancer always improves quality of lifeand/or patient survival.Bob Barrett: Well, given this long list of requirements, howfeasible is it to identify circulating biomarkers forearly detection of cancer?Dr. Danijela Konforte: This is exactly the question that researchers SharonHori and Sanjiv Gambhir from Stanford UniversitySchool of Medicine tried to tackle in their articlepublished in Journal Science Translational Medicine atthe end of 2011.The first objective of this study was to usemathematical modeling to quantify the time requiredfor growing malignant tumor to reach a sufficient sizeso that its blood biomarker levels can be detected bycurrently available blood tests.Ovarian cancer and CA-125 biomarker were used toprovide realistic baseline values for model simulation.Ovarian cancer was chosen because it remainsrelatively asymptomatic until advanced and there is asignificant opportunity for improvements in earlydetection.CA-125 is considered a gold standard biomarker testfor surveillance of women with epithelial ovariancancer. It is not a screening test, but the mainadvantage is that it has been sufficiently studied withall the required model parameter values availablefrom the literature.The second object of the study by Hori and Gambhirwas to use the model to identify biomarker relatedparameters that most greatly affect early cancerdetection, and also quantifies through simulationshow much each baseline parameter value has tochange to achieve early tumor detection.Tumor biomarker parameters that were tested in themodel included grade of tumor biomarker sheddinginto the blood, tumor marker clearance, and thepercentage of the tumor volume consisting of tumorcells.They also modeled in analytical sensitivity ofclinically available biomarker tests. The authorschose a solid tumor with the diameter of onemillimeter as their goal for early detection. This isquite an ambitious goal in my opinion and I will comeback to this point a bit later in the discussion.Briefly, the model was designed to predict changes inthe blood biomarker levels as a function of time, andto relate them to the corresponding tumor burden,meaning tumor volume or tumor diameter.Two growth models were used in the study. The firstmodel assumed exponentially growing tumor,starting from its genesis. The second and morephysiologically plausible model assumed both mono-exponential growth as well as tumor decay.For each growth model the authors tested twoscenarios. In one scenario a biomarker was 100%tumor specific, and in the other, a biomarker wassecreted by both tumor and normal self.So here I described a study model in very broadstrokes and I would like to encourage our listeners toread the original article for more details on thespecifics of the mathematical model used.Bob Barrett: Well, let’s get to the last page of that, can yousummarize the main findings of that study by Horiand Gambhir?Dr. Danijela Konforte: Well, the simulation based analysis identifiedparameters that are useful in improving early cancerdetection, and those are tumor marker sheddingrates, biomarker specificity, and assay analyticalsensitivity.Importantly, the study also identified parametersthat do not improve early detection, and those arefraction of the biomarker reaching bloods, and ratesof its elimination from the circulation.In addition the model quantified how far theparameters I have just mentioned must be perturbedto achieve early--in this case, submillimeter--detection of cancer.So the estimated time until detection by current CA-125 test was found to be 10.6 to 12.6 years at whichpoint ovarian tumor is about 4 centimeters indiameter and this agrees with what is currently seenwith the transvaginal ultrasound process.According to the model to detect a tumor with adiameter of 1 millimeter would require a biomarkerthat is almost 100% tumor specific, and hasshedding rates of about 10,000 times higher thanthat of any known protein tumor biomarker.Additionally, further improvements in the analyticalsensitivity of current clinical assays by 10,000 foldwould also be required. This way the tumor would bedetected in 5.6 years which would provide us reallywith about 4 to 6 years of lead time advantage overcurrent detection methods.Collectively as you can see these results indicate thatit may not be feasible to use a single circulatingbiomarker for early detection of cancer.Bob Barrett: Every study has its limitations, what are thelimitations of this study?Dr. Danijela Konforte: Well direct extrapolation of the model predictions tothe clinical use is hard to validate for severalreasons. One, tumor age cannot be accuratelymeasured at clinical diagnosis.And two, there are no patient data correlating tumorsize with blood biomarker levels either before andafter cancer diagnosis or for multiple time pointsthroughout the natural course of disease progression.So this relationship between tumor size and bloodbiomarker levels that the model is based on is notreally well understood.The model may not be useful for cancers whoseparameters are not available from the literature, i.e.those cancers that haven’t been extensivelyresearched like ovarian cancer. This means a lot ofassumptions have to made in the modeling itself.A target of one millimeter for early detection that theauthor sets, may not be applicable or even necessaryin my opinion for every type of cancer. The onemillimeter target is more appropriate for earlydetection of an aggressive tumor with a shortdoubling time, than for a slow growing indolenttumor with a long doubling time.So a small improvement in early detection will affectthe lead time of indolent tumors much moreappreciably than that of aggressive tumors.I think that the goals of early cancer detection stillneed to be debated among researchers andclinicians, so when selecting criteria for a bloodbiomarker of interest, researchers have to considerthe type of cancer and its aggressiveness.Bob Barrett: How do you think the international researchcommunity can benefit from this and similarmathematical models in their efforts to identify thosebiomarkers for early detection of cancer?Dr. Danijela Konforte: I think models like this can be used to address thepotential and limitations of tumor biomarkers in theearly investigative stages. They can certainly helpresearchers to identify criteria for prioritizingbiomarkers.For example, some may be more feasible to studythan others. This can not only save time, but canalso help focus valuable resources that are so difficultto come by these days.Furthermore, mathematical models like this one canbe used to perform simulations quickly across a widerange of biomarker related parameters.Such simulations can also encompass the large inter-and intra- individual biomarker variation, in otherwords biological variability, that may exist for sometypes of cancer, and would make the modelgeneralizable for any solid cancer that secretes thebiomarker into circulation.With the current version of this model, only one ortwo tumor related parameters can be manipulated ata time. Future versions should include simulationsthat are simultaneous of multiple parameters. Myhope also is that models like this will be freelyavailable to the researchers.Bob Barrett: Well finally, doctor, where do you think researchersshould aim their efforts in order to make blood basedbiomarkers for early detection of cancer a reality?Dr. Danijela Konforte: I think the study by Hori and Gambhir clearly showsthat mathematical models can be important tools inthe evaluation of relevant parameters of bloodbiomarkers for early detection of cancer.However, we have to understand that the models areas good as the assumptions they are based on, andas good as the baseline clinical parameters obtainedfrom biological data which are used in simulationstudies.So what is needed in the future? For one I think weneed to expand our knowledge of the natural processof cancer initiation and progression. We need to domore research to better understand how tumor sizerelates to biomarker blood levels.For instance what are in vivo biomarker sheddingrates, what are the effects of tumor micro-environment on those shedding rates? What fractionof biomarker is reaching the blood, and how do theseparameters change with time?These findings will clearly lead to development ofmulti-scale predictive mathematical models that canmore accurately select characteristics of biomarkersthat are necessary to improve early detection.Also advancements in the areas such as nanotechnology will help improve much needed analyticalsensitivity of tumor biomarker assays.We usually talk about protein biomarkers. However,the research should also include non-protein bloodbiomarkers such as tumor specific microRNAs,epigenetic biomarkers, mitochondrial DNA markers,post translational modification, as well as anti-tumorimmune response markers.As this study showed it may not be feasible to rely ona single blood test for early detection of cancer. Acombination of a panel of circulating biomarkers anddiagnostic imaging procedures is more likely to dothe job.Bob Barrett: Dr. Danijela Konforte is a Clinical Biochemist atLifeLabs, a community laboratory in Toronto. She hasbeen our guest in this podcast from ClinicalChemistry. I am Bob Barrett, thanks for listening.。

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