JAMA：超声波筛检或MRI对乳腺癌风险增加的女性有裨益

4月4日，国际杂志《美国医学会期刊》JAMA上的一项研究披露，在对那些乳腺癌风险增加且乳腺组织致密的妇女进行年度乳腺造影之外再加上一种筛检性超声波检查或核磁共振成像（MRI）可令附带性发现乳腺癌的比率增加。

根据文章的背景资料：“年度超声波筛检可发现在乳腺造影时没有看到的小的、淋巴结阴性的乳腺癌。核磁共振成像可发现乳腺造影和超声波筛检所没有看到的其它的乳腺癌。”

前费城美国放射学成像学院网的Wendie A. Berg， M.D.， Ph.D.及其同事开展了一项研究，旨在确认超声波和MRI检查在罹患乳腺癌风险增加的妇女中的追加的癌症检测率。该研究包括在21个场所的2，809位妇女（她们的患癌风险增加并有致密的乳腺），她们同意进行3次年度的、以随机顺序进行的乳腺造影和超声波的独立筛检。

共有2，662名妇女接受了7，473次乳腺造影和超声波筛检，她们中有110人发现有111次乳腺癌事件。乳腺造影发现了59起癌症（53%），其中包括仅由乳腺造影发现的33起癌症（30%）；仅由超声波检查发现的32起癌症（29%）及9起（8%）在乳腺造影和超声波检查都没有发现有癌症时仅由MRI发现的癌症。有11起癌症（10%）未能被任何的成像筛检发现。在MRI亚组研究的612名妇女中，共有16人（2.6%）被诊断患有乳腺癌。

在第二年和第三年结合在一起的4，814起筛检中，有75名妇女被诊断患有癌症。研究人员发现，补充性超声波检查增加了每次年度筛检时检测到的癌症， 超越了乳腺造影所检测到的癌症，即在第一年中在每1，000名妇女中多检测到5.3个癌症；在第二和第三年的每一年中在每1，000名妇女中多检测到3.7位妇女的癌症；在3次的年度筛检中平均在每1，000名妇女中可检测到4.3名患癌的妇女。添加MRI筛检可进一步增加对癌症的检测，其追加的癌症检测率为每1000名女性中有14.7个癌症。检测到1个癌症所需的筛检数在乳腺造影中为127次；在补充性超声波检查中为234次，在乳腺造影加上超声波筛检为阴性结果后的追加性MRI检查为68次。

文章的作者得出结论：“尽管其有着较高的敏感性，但在更广泛的具有致密乳腺的中度风险妇女人群中，特别是当考虑到目前存在的高假阳性率、高成本及对MRI的容忍性降低时，在乳腺造影检查基础上再添加MRI筛检而非超声波检查可能并不恰当。”（生物谷Bioon.com）

doi:10.1001/jama.2012.388
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Detection of Breast Cancer With Addition of Annual Screening Ultrasound or a Single Screening MRI to Mammography in Women With Elevated Breast Cancer Risk

Wendie A. Berg, MD, PhD; Zheng Zhang, PhD; Daniel Lehrer, MD; Roberta A. Jong, MD; Etta D. Pisano, MD; Richard G. Barr, MD, PhD; Marcela Böhm-Vélez, MD; Mary C. Mahoney, MD; W. Phil Evans III, MD; Linda H. Larsen, MD; Marilyn J. Morton, DO; Ellen B. Mendelson, MD; Dione M. Farria, MD; Jean B. Cormack, PhD; Helga S. Marques, MS; Amanda Adams, MPH; Nolin M. Yeh, MS; Glenna Gabrielli, BS for the ACRIN 6666 Investigators

Context Annual ultrasound screening may detect small, node-negative breast cancers that are not seen on mammography. Magnetic resonance imaging (MRI) may reveal additional breast cancers missed by both mammography and ultrasound screening.

Objective To determine supplemental cancer detection yield of ultrasound and MRI in women at elevated risk for breast cancer.

Design, Setting, and Participants From April 2004-February 2006, 2809 women at 21 sites with elevated cancer risk and dense breasts consented to 3 annual independent screens with mammography and ultrasound in randomized order. After 3 rounds of both screenings, 612 of 703 women who chose to undergo an MRI had complete data. The reference standard was defined as a combination of pathology (biopsy results that showed in situ or infiltrating ductal carcinoma or infiltrating lobular carcinoma in the breast or axillary lymph nodes) and 12-month follow-up.

Main Outcome Measures Cancer detection rate (yield), sensitivity, specificity, positive predictive value (PPV3) of biopsies performed and interval cancer rate.

Results A total of 2662 women underwent 7473 mammogram and ultrasound screenings, 110 of whom had 111 breast cancer events: 33 detected by mammography only, 32 by ultrasound only, 26 by both, and 9 by MRI after mammography plus ultrasound; 11 were not detected by any imaging screen. Among 4814 incidence screens in the second and third years combined, 75 women were diagnosed with cancer. Supplemental incidence-screening ultrasound identified 3.7 cancers per 1000 screens (95% CI, 2.1-5.8; P < .001). Sensitivity for mammography plus ultrasound was 0.76 (95% CI, 0.65-0.85); specificity, 0.84 (95% CI, 0.83-0.85); and PPV3, 0.16 (95% CI, 0.12-0.21). For mammography alone, sensitivity was 0.52 (95% CI, 0.40-0.64); specificity, 0.91 (95% CI, 0.90-0.92); and PPV3, 0.38 (95% CI, 0.28-0.49; P < .001 all comparisons). Of the MRI participants, 16 women (2.6%) had breast cancer diagnosed. The supplemental yield of MRI was 14.7 per 1000 (95% CI, 3.5-25.9; P = .004). Sensitivity for MRI and mammography plus ultrasound was 1.00 (95% CI, 0.79-1.00); specificity, 0.65 (95% CI, 0.61-0.69); and PPV3, 0.19 (95% CI, 0.11-0.29). For mammography and ultrasound, sensitivity was 0.44 (95% CI, 0.20-0.70, P = .004); specificity 0.84 (95% CI, 0.81-0.87; P < .001); and PPV3, 0.18 (95% CI, 0.08 to 0.34; P = .98). The number of screens needed to detect 1 cancer was 127 (95% CI, 99-167) for mammography; 234 (95% CI, 173-345) for supplemental ultrasound; and 68 (95% CI, 39-286) for MRI after negative mammography and ultrasound results.

Conclusion The addition of screening ultrasound or MRI to mammography in women at increased risk of breast cancer resulted in not only a higher cancer detection yield but also an increase in false-positive findings.

Trial Registration clinicaltrials.gov Identifier: NCT00072501