Lawrence S Bloomberg Faculty of Nursing, University of Toronto, Toronto, Canada.
Br J Cancer. 2011 Apr 26;104(9):1384-92. doi: 10.1038/bjc.2011.120. Epub 2011 Apr 12.
The objective of this study was to estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers; and measure the extent to which host, family history, and cancer treatment-related factors modify the risk.
Patients were 810 women, with stage I or II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up.
Overall, 149 subjects (18.4%) developed a contralateral breast cancer. The 15-year actuarial risk of contralateral breast cancer was 36.1% for women with a BRCA1 mutation and was 28.5% for women with a BRCA2 mutation. Women younger than 50 years of age at the time of breast cancer diagnosis were significantly more likely to develop a contralateral breast cancer at 15 years, compared with those older than 50 years (37.6 vs 16.8%; P=0.003). Women aged <50 years with two or more first-degree relatives with early-onset breast cancer were at high risk of contralateral breast cancer, compared with women with fewer, or no first-degree relatives with breast cancer (50 vs 36%; P=0.005). The risk of contralateral breast cancer was reduced with oophorectomy (RR 0.47; 95% CI 0.30-0.76; P=0.002).
The risk of contralateral breast cancer risk in BRCA mutation carriers declines with the age of diagnosis and increases with the number of first-degree relatives affected with breast cancer. Oophorectomy reduces the risk of contralateral breast cancer in young women with a BRCA mutation.
本研究旨在评估 BRCA1 和 BRCA2 携带者发生对侧乳腺癌的风险，并衡量宿主、家族史和癌症治疗相关因素对风险的影响程度。
患者为 810 名患有 I 期或 II 期乳腺癌的女性，这些患者的家族中发现了 BRCA1 或 BRCA2 突变。患者从癌症首次诊断开始随访，直至对侧乳房切除术、对侧乳腺癌、死亡或最后一次随访。
总体而言，149 例（18.4%）患者发生对侧乳腺癌。BRCA1 突变患者 15 年的对侧乳腺癌累积发生率为 36.1%，BRCA2 突变患者为 28.5%。诊断乳腺癌时年龄小于 50 岁的女性，与年龄大于 50 岁的女性相比，15 年内发生对侧乳腺癌的可能性明显更高（37.6% vs. 16.8%；P=0.003）。年龄<50 岁且有 2 个或更多有早发性乳腺癌的一级亲属的女性，发生对侧乳腺癌的风险较高，而一级亲属中有较少或没有乳腺癌的女性（50% vs. 36%；P=0.005）。卵巢切除术降低了对侧乳腺癌的风险（RR 0.47；95%CI 0.30-0.76；P=0.002）。
BRCA 突变携带者对侧乳腺癌的风险随诊断年龄的增加而降低，随受影响一级亲属数量的增加而增加。卵巢切除术可降低携带 BRCA 突变的年轻女性对侧乳腺癌的风险。
