Abstract：
The risk of early-onset (EO) breast cancer is known to be increased in relatives of EO breast cancer patients, but less is known about the familial risk of other EO cancers. We assessed familial risks of EO cancers (aged ≤40 years) other than breast cancer in 54 753 relatives of 5562 women with EO breast cancer (probands) by using a population-based cohort from Finland. Standardized incidence ratios (SIRs) and 95% confidence intervals (CI) were estimated by using gender-, age- and period-specific cancer incidences of the general population as reference. The risk of any cancer excluding breast cancer in first-degree relatives was comparable to population cancer risk (SIR 0.99, 95% CI: 0.84-1.16). Siblings\' children of women with EO breast cancer were at an elevated risk of EO testicular and ovarian cancer (SIR = 1.74, 95% CI: 1.07-2.69 and 2.69, 95% CI: 1.08-5.53, respectively). The risk of EO pancreatic cancer was elevated in siblings of the probands (7.61, 95% CI: 1.57-22.23) and an increased risk of any other cancer than breast cancer was observed in children of the probands (1.27, 95% CI: 1.03-1.55). In conclusion, relatives of women with EO breast cancer are at higher familial risk of certain discordant EO cancers, with the risk extending beyond first-degree relatives.
摘要：
已知早发性（EO）乳腺癌的风险在EO乳腺癌患者的亲属中增加，但对其他EO癌症的家族风险知之甚少。我们使用来自芬兰的基于人群的队列，在5562名EO乳腺癌（先证者）的54753名亲属中评估了除乳腺癌以外的EO癌症（年龄≤40岁）的家族风险。标准化发生率(SIR)和95%置信区间(CI)通过使用性别、一般人群的年龄和时期特异性癌症发病率作为参考。一级亲属中除乳腺癌以外的任何癌症的风险与人群癌症风险相当(SIR0.99,95%CI:0.84-1.16)。患有EO乳腺癌的妇女的兄弟姐妹子女患EO睾丸癌和卵巢癌的风险升高（SIR=1.74，95％CI：1.07-2.69和2.69，95％CI：1.08-5.53，分别）。先证者的兄弟姐妹患EO胰腺癌的风险升高（7.61，95％CI：1.57-22.23），并且在先证者的儿童中观察到比乳腺癌任何其他癌症的风险增加（1.27，95％CI：1.03-1.55）。总之,患有EO乳腺癌的女性亲属患某些不一致的EO癌症的家族风险较高，风险超出一级亲属。
