Department of Epidemiology, Netherlands Cancer Institute, Amsterdam, The Netherlands.
Breast Cancer Res Treat. 2011 Feb;126(1):193-202. doi: 10.1007/s10549-010-1120-8. Epub 2010 Aug 21.
Obesity is an established risk factor for postmenopausal breast cancer in the general population. However, it is still unclear whether this association also exists in BRCA1/2 mutation carriers. We investigated the association between self-reported anthropometric measures and breast cancer risk in a nationwide retrospective cohort study, including 719 BRCA1/2 carriers, of whom 218 had been diagnosed with breast cancer within 10 years prior to questionnaire completion. All time-varying Cox proportional hazards analyses were stratified by menopausal status. For premenopausal breast cancer, no statistically significant associations were observed for any of the anthropometric measures. The association between body mass index (BMI) at age 18 and premenopausal breast cancer risk suggested a trend of decreasing risk with increasing BMI (HR(22.50-24.99 vs. 18.50-22.49) = 0.83, 95% CI = 0.47-1.44 and HR(≥ 25.00 vs. 18.50-22.49) = 0.41, 95% CI = 0.13-1.27). For postmenopausal breast cancer, being 1.67 m and taller increased the risk 1.7-fold (HR = 1.67, 95% CI = 1.01-2.74) when compared to a height <1.67 m. Compared with a current body weight < 72 kg, a current body weight of ≥ 72 kg increased the risk of postmenopausal breast cancer 2.1-fold (95% CI = 1.23-3.59). A current BMI of ≥ 25.0 kg/m², an adult weight gain of 5 kg or more, and a relative adult weight gain of 20% or more were all non-significantly associated with a 50-60% increased risk of postmenopausal breast cancer [HR = 1.46 (0.86-2.51), HR = 1.56 (95% CI = 0.85-2.87), and HR = 1.60 (95% CI = 0.97-2.63), respectively], when compared with having a healthy or stable weight. No associations for body weight or BMI at age 18 were observed. In conclusion, menopausal status seemed to modify the association between body weight and breast cancer risk among BRCA1/2 carriers. We observed no clear association between body weight and premenopausal breast cancer, while overweight and weight gain increased postmenopausal breast cancer risk. Carriers may reduce their risk of postmenopausal breast cancer by maintaining a healthy body weight throughout life.
肥胖是一般人群中绝经后乳腺癌的既定风险因素。然而，BRCA1/2 突变携带者中是否也存在这种关联仍不清楚。我们在一项全国性回顾性队列研究中调查了自我报告的人体测量指标与乳腺癌风险之间的关系，该研究纳入了 719 名 BRCA1/2 携带者，其中 218 名在完成问卷前 10 年内被诊断患有乳腺癌。所有时间变化的 Cox 比例风险分析均按绝经状态分层。对于绝经前乳腺癌，任何人体测量指标均未观察到统计学上显著的关联。18 岁时体重指数（BMI）与绝经前乳腺癌风险之间的关联表明，BMI 增加与风险降低呈趋势相关（HR（22.50-24.99 与 18.50-22.49）=0.83，95%CI=0.47-1.44 和 HR（≥25.00 与 18.50-22.49）=0.41，95%CI=0.13-1.27）。对于绝经后乳腺癌，与身高<1.67 m 相比，身高为 1.67 m 或更高的患者风险增加 1.7 倍（HR=1.67，95%CI=1.01-2.74）。与当前体重<72 kg 相比，当前体重≥72 kg 增加了绝经后乳腺癌的风险 2.1 倍（95%CI=1.23-3.59）。当前 BMI≥25.0 kg/m²、成年后体重增加 5 kg 或更多，以及相对成人体重增加 20%或更多，与绝经后乳腺癌风险增加 50-60%均无显著相关性[HR=1.46（0.86-2.51），HR=1.56（95%CI=0.85-2.87）和 HR=1.60（95%CI=0.97-2.63）]，与体重健康或稳定相比。18 岁时的体重或 BMI 与体重无关联。总之，绝经状态似乎改变了 BRCA1/2 携带者体重与乳腺癌风险之间的关联。我们未观察到体重与绝经前乳腺癌之间有明确关联，而超重和体重增加增加了绝经后乳腺癌的风险。携带者可以通过终生保持健康的体重来降低绝经后乳腺癌的风险。
