2015年12月23日，一项发表在《临床肿瘤学》杂志上的研究表明，BRCA1/2突变体携带者可增加患对侧乳腺癌的风险 (CBC)，随着年龄的增长首次诊断为对侧乳腺癌的风险会增加。
荷兰阿姆斯特丹癌症研究所Alexandra J. van den Broek和他的同事们检测了携带或不携带BRCA1/2突变体的乳腺癌病人整体组和不同年龄组患有对侧乳腺癌风险的预估。这些数据包括6294例被诊断为浸润性乳腺癌的患者，他们平均在50岁以下并且在1970年和2003年之间接受过治疗；研究的参与者接受了最普遍的BRCA1/2突变体检测。
研究人员通过平均12年半的随访在研究对象中发现了578名对侧乳腺癌患者。与未携带突变体者相比，BRCA1和BRCA2突变体携带者患对侧乳腺癌的风险较高(风险率分别为3.31和2.17)。累积10年期BRCA1携带者患对侧乳腺癌风险是21.1%，BRCA2携带者患对侧乳腺癌风险是10.8%，未携带突变体者患对侧乳腺癌风险是5.1%。仅仅在BRCA1/2携带者中，首次诊断为乳腺癌的年龄组有较高的患对侧乳腺癌的风险；累积10年期小于41岁的乳腺癌患者患有对侧乳腺癌风险是23.9% ，相比之下， 41岁至49岁之间的乳腺癌患者患有对侧乳腺癌的风险为12.6%(P = 0.02)。
考虑到现有证据，不同年龄组风险估计应该被包括在内。作者写道。
doi: 10.1200/JCO.2015.62.3942
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Impact of Age at Primary Breast Cancer on Contralateral Breast Cancer Risk in BRCA1/2 Mutation Carriers
Alexandra J. van den Broek, Laura J. van t Veer, Maartje J. Hooning, Sten Cornelissen, Annegien Broeks, Emiel J. Rutgers, Vincent T.H.B.M. it, Cees J. Cornelisse, Mike van Beek, Maryska L. Janssen-Heijnen, Caroline Seynaeve, Pieter J. Westenend, Jan J. Jobsen, Sabine Siesling, Rob A.E.M. Tollenaar, Flora E. van Leeuwen and Marjanka K. Schmidt
Purpose To determine prospectively overall and age-specific estimates of contralateral breast cancer (CBC) risk for young patients with breast cancer with or without BRCA1/2 mutations. Patients and Methods A cohort of 6,294 patients with invasive breast cancer diagnosed under 50 years of age and treated between 1970 and 2003 in 10 Dutch centers was tested for the most prevalent BRCA1/2 mutations. We report absolute risks and hazard ratios within the cohort from competing risk yses. Results After a median follow-up of 12.5 years, 578 CBCs were observed in our study population. CBC risk for BRCA1 and BRCA2 mutation carriers was two to three times higher than for noncarriers (hazard ratios, 3.31 [95% CI, 2.41 to 4.55; P <.001] and 2.17 [95% CI,1.22 to 3.85; P = .01], respectively). Ten-year cumulative CBC risks were 21.1% (95% CI, 15.4 to 27.4) for BRCA1, 10.8% (95% CI, 4.7 to 19.6) for BRCA2 mutation carriers and 5.1% (95% CI, 4.5 to 5.7) for noncarriers. Age at diagnosis of the first breast cancer was a significant predictor of CBC risk in BRCA1/2 mutation carriers only; those diagnosed before age 41 years had a 10-year cumulative CBC risk of 23.9% (BRCA1: 25.5%; BRCA2: 17.2%) compared with 12.6% (BRCA1: 15.6%; BRCA2: 7.2%) for those 41 to 49 years of age (P = .02); our review of published studies showed ranges of 24% to 31% before age 40 years (BRCA1: 24% to 32%; BRCA2:17% to 29%) and 8% to 21% after 40 years (BRCA1: 11% to 52%; BRCA2: 7% to 18%), respectively.
