乳腺磁共振成像补充筛查可改善乳腺癌平均风险女性的早期诊断

乳腺磁共振成像补充筛查可改善乳腺癌平均风险女性的早期诊
断
乳腺癌仍然是女性癌症死亡的主要原因，有充分理由寻求改进方法。

长期以来，磁共振（MR）成像被公认为有效的乳腺癌筛查方法，比乳腺钼靶摄影和超声的灵敏度更好。

目前，指南为有家族史或其他特定乳腺癌风险因素的女性保留乳腺MR成像检查。

既往研究认为MR 成像筛查对于平均风险女性而言并不必需，并且由于成本较高，MR成像在人群中的普及存在障碍。

2017年2月21日，北美放射学会官方期刊《放射学》在线发表德国亚琛大学、波恩大学的研究报告，发现MR成像作为补充筛查工具可改善乳腺癌平均风险女性的早期诊断效果。

该前瞻观察研究于2005年1月～2013年12月入组德国亚琛大学和波恩大学乳腺医学中心2120位无乳腺癌相关风险因素（终生风险＜15%）且常规影像结果正常（乳腺钼靶筛查±超声筛查）的40～70岁女性进行MR成像补充筛查。

如果发生乳腺癌，残留乳腺组织量至少可供病理检查（美国放射学会分类A～D）。

结局衡量指标为癌症补充检出率、筛查间期癌症发生率、MR成像补充检出癌症的生物学特征、MR成像筛查的特异度（真阴性率）和阳性预测值（PPV）。

使用组织学诊断或2年随访确定参考标准。

结果共进行了3861次MR成像检查，人均观察期3.3年。

乳腺MR成像补充发现60例乳腺癌（导管原位癌20例，浸润癌40例），总的癌症补充检出率为15.5‰（95%置信区间：11.9～20.0）。

初次筛查时补充检出48例乳腺癌（癌症补充检出率为22.6‰）。

后续筛查1741次，发生13例癌症，其中12例由MR成像单独发现（癌症补充检出率为6.9‰）。

1例癌症被3种方法（乳腺钼靶、超声、MR 成像）同时检出，其余59例仅被MR成像检出，无癌症病例仅被乳腺钼靶或仅被超声检出。

MR成像诊断出的癌症都较小（中位8mm），93.4%的病例为淋巴结阴性，未分化（高分级癌症）筛查患病率为41.7%、筛查发病率为46.0%。

未见筛查间期癌症。

MR成像筛查的特
异度高（97.1%，95%置信区间：96.5～97.6）、PPV高（35.7%，95%置信区间：28.9～43.1）。

因此，对于乳腺癌平均风险女性, MR成像筛查可改善预后相关性乳腺癌的早期诊断。

相关阅读
•磁共振成像虽然昂贵，但是其乳腺癌筛查敏感性将近100%
•3.0T磁共振扩散张量成像对乳腺肿块性病变的鉴别诊断价值
Radiology. 2017 Feb 21:161444. [Epub ahead of print]
Supplemental Breast MR Imaging Screening of Women with Average Risk of Breast Cancer.
Kuhl CK, Strobel K, Bieling H, Leutner C, Schild HH, Schrading S.
University of Aachen, Aachen, Germany; University of Bonn, Bonn, Germany.
PURPOSE: T o investigate the utility and accuracy of breast magnetic resonance (MR) imaging as a supplemental screening tool in women at average risk for breast cancer and to investigate the types of cancer detected with MR imaging screening.
MATERIALS AND METHODS: This prospective observational study was conducted at two academic breast centers in women aged 40-70 years without breast cancer-associated risk factors (lifetime risk <15%). Between January 2005 and December 2013, women with at least minimal residual breast tissue (American College of Radiology categories A-D) and normal conventional imaging findings (screening mammography with or without screening ultrasonography [US]) were invited to undergo supplemental MR imaging screening. Outcome measures were supplemental cancer detection rates, interval cancer rates, and biologic profiles of MR imaging-detected additional cancers, as well as specificity and positive predictive value (PPV) of MR
imaging screening. Tissue diagnoses or 2 years of follow-up were used to establish the reference standard.
RESULTS: A total of 2120 women were recruited and underwent 3861 screening MR imaging studies, covering an observation period of 7007 women-years. Breast MR imaging depicted 60 additional breast cancers (ductal carcinoma in situ, n = 20; invasive carcinoma, n = 40) for an overall supplemental cancer detection rate of 15.5 per 1000 cases (95% confidence interval [CI]: 11.9, 20.0). Forty-eight additional cancers were detected with MR imaging at initial screening (supplemental cancer detection rate, 22.6 per 1000 cases). During the 1741 subsequent screening rounds, 12 of 13 incident cancers were found with MR imaging alone (supplemental cancer detection rate, 6.9 per 1000 cases). One cancer was diagnosed with all three methods (mammography, US, and MR imaging), and none were diagnosed with mammography only or US only. Cancers diagnosed with MR imaging were small (median, 8 mm), node negative in 93.4% of cases, and dedifferentiated (high-grade cancer) in 41.7% of cases at prevalence screening and 46.0% of cases at incidence screening. No interval cancers were observed. MR imaging screening offered high specificity (97.1%; 95% CI: 96.5, 97.6) and high PPV (35.7%; 95% CI: 28.9, 43.1).
CONCLUSION: In women at average risk for breast cancer, MR imaging screening improves early diagnosis of prognostically relevant breast cancer.
PMID: 28221097
DOI: 10.1148/radiol.2016161444。