Women's College Research Institute, Women's College Hospital, 76 Grenville St., 6th Floor, Toronto, ON, M5S 1B2, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
Breast Cancer Res Treat. 2018 Sep;171(2):421-426. doi: 10.1007/s10549-018-4822-y. Epub 2018 May 17.
In the general population, an early age at first full-term birth confers protection against the risk of developing breast cancer. The relationship between age at first birth and breast cancer risk is not clear for women with a mutation in the BRCA1 or BRCA2 gene. Thus, we undertook a case-control study of women with a BRCA1 or BRCA2 mutation to study the effects of age at first full-term birth matched for other reproductive factors.
Information about reproductive factors, including age at first birth as well as medical history, was collected from a routinely administered research questionnaire. There were 2,295 matched pairs of women with a BRCA1 or BRCA2 mutation included in the final analysis.
There was no significant difference in the mean age at first full-term birth among the BRCA1 (24.9 vs. 25.2; P = 0.10) or BRCA2 mutation carriers (26.5 vs. 26.6 years; P = 0.80). Findings were similar in the analysis limited to cases who were diagnosed with breast cancer prior to age 45.
This matched analysis of a large number of BRCA mutation carriers suggests that age at first birth has little influence on BRCA1 or BRCA2 breast cancer risk.
在普通人群中，初次足月分娩的年龄较早可降低乳腺癌发病风险。对于携带 BRCA1 或 BRCA2 基因突变的女性，初次分娩年龄与乳腺癌风险之间的关系尚不清楚。因此，我们开展了一项针对携带 BRCA1 或 BRCA2 基因突变的女性的病例对照研究，以研究初次足月分娩年龄对其他生殖因素的影响。
从常规管理的研究问卷中收集了有关生殖因素的信息，包括初次分娩年龄以及病史。最终分析纳入了 2,295 对 BRCA1 或 BRCA2 基因突变的匹配女性。
BRCA1 突变携带者（24.9 岁比 25.2 岁；P=0.10）或 BRCA2 突变携带者（26.5 岁比 26.6 岁；P=0.80）的初次足月分娩年龄均值无显著差异。在限定于 45 岁前被诊断为乳腺癌的病例分析中，结果相似。
本研究对大量 BRCA 突变携带者进行了匹配分析，结果表明初次分娩年龄对 BRCA1 或 BRCA2 乳腺癌风险的影响较小。
