Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, The University of Melbourne, Level 1, 723 Swanston Street, Melbourne, Carlton VIC 3053, Australia.
Br J Cancer. 2010 Sep 28;103(7):1103-8. doi: 10.1038/sj.bjc.6605876. Epub 2010 Sep 7.
Little is known regarding cancer risks for relatives of women with very early-onset breast cancer.
We studied 2208 parents and siblings of 504 unselected population-based Caucasian women with breast cancer diagnosed before age 35 years (103 from USA, 124 from Canada and 277 from Australia), 41 known to carry a mutation (24 in BRCA1, 16 in BRCA2 and one in both genes). Cancer-specific standardised incidence ratios (SIRs) were estimated by comparing the number of affected relatives (50% verified overall) with that expected based on incidences specific for country, sex, age and year of birth.
For relatives of carriers, the female breast cancer SIRs were 13.13 (95% CI 6.57-26.26) and 12.52 (5.21-30.07) for BRCA1 and BRCA2, respectively. The ovarian cancer SIR was 12.38 (3.1-49.51) for BRCA1 and the prostate cancer SIR was 18.55 (4.64-74.17) for BRCA2. For relatives of non-carriers, the SIRs for female breast, prostate, lung, brain and urinary cancers were 4.03 (2.91-5.93), 5.25 (2.50-11.01), 7.73 (4.74-12.62), 5.19 (2.33-11.54) and 4.35 (1.81-10.46), respectively. For non-carriers, the SIRs remained elevated and were statistically significant for breast and prostate cancer when based on verified cancers.
First-degree relatives of women with very early-onset breast cancer are at increased risk of cancers not explained by BRCA1 and BRCA2 mutations.
对于发病年龄早于 35 岁的女性乳腺癌患者的亲属，我们对其癌症风险知之甚少。
我们研究了 504 名发病年龄早于 35 岁（其中 103 例来自美国，124 例来自加拿大，277 例来自澳大利亚）的未经选择的白种人群中乳腺癌患者的 2208 位父母和兄弟姐妹，其中 41 例已知携带突变（24 例为 BRCA1，16 例为 BRCA2，1 例同时携带两种基因）。通过比较（总体 50%经证实）受累亲属的数量与根据国家、性别、年龄和出生年份确定的发病率计算出特定癌症的标准化发病比（SIR）。
对于突变携带者的亲属，BRCA1 和 BRCA2 的女性乳腺癌 SIR 分别为 13.13（95%CI 6.57-26.26）和 12.52（5.21-30.07）。BRCA1 的卵巢癌 SIR 为 12.38（3.1-49.51），BRCA2 的前列腺癌 SIR 为 18.55（4.64-74.17）。对于非携带者的亲属，女性乳腺癌、前列腺癌、肺癌、脑癌和膀胱癌的 SIR 分别为 4.03（2.91-5.93）、5.25（2.50-11.01）、7.73（4.74-12.62）、5.19（2.33-11.54）和 4.35（1.81-10.46）。对于非携带者，当基于经证实的癌症时，乳腺癌和前列腺癌的 SIR 仍然升高且具有统计学意义。
发病年龄早于 35 岁的女性乳腺癌患者的一级亲属患乳腺癌和前列腺癌的风险增加，这不能用 BRCA1 和 BRCA2 突变来解释。
