Epidemiology Research Program, American Cancer Society, Atlanta, GA, USA.
, 250 Williams Street NW, Atlanta, GA, 30303, USA.
Breast Cancer Res Treat. 2018 Jan;167(1):133-145. doi: 10.1007/s10549-017-4470-7. Epub 2017 Aug 31.
Nearly half of the 3.5 million female breast cancer survivors in the US are aged 65 years or older at diagnosis, yet little is known about associations of obesity and physical activity with breast cancer-specific mortality (BCSM) among older survivors.
Between 1992 and 2013, 5254 women in the Cancer Prevention Study-II Nutrition Cohort were diagnosed with local or regional breast cancer among whom 1771 deaths (505 breast cancer deaths) occurred. Multivariable Cox proportional hazards regression models were used to examine associations of pre- and post-diagnosis body mass index (BMI) and moderate-vigorous physical activity (MET-hours/week) with mortality outcomes stratified by age at diagnosis (<65, ≥65 years).
Among women ≥65 years of age at diagnosis (n = 4226), pre- and post-diagnosis BMI (per 5 kg/m) were associated with a higher risk of BCSM (pre-diagnosis, HR 1.27, 95% CI 1.14-1.41; post-diagnosis, HR 1.19, 95% CI 1.04, 1.36); neither pre- nor post-diagnosis physical activity was associated with BCSM. Among women <65 years of age at diagnosis (n = 1028), BMI at both time points were not significantly associated with BCSM; however, there was a significant inverse trend of post-diagnosis physical activity with BCSM (P-trend = 0.01). Among both age groups, BMI and physical activity, regardless of when assessed, were significantly associated with all-cause mortality.
Higher BMI, pre- or post-diagnosis, was associated with a higher risk of BCSM in older patients, independent of comorbidities and stage at diagnosis. Weight management should be discussed even with women aged 65 years or older to lower rates of BCSM.
在美国，350 万女性乳腺癌幸存者中，近一半在诊断时年龄在 65 岁或以上，但对于肥胖和身体活动与老年幸存者的乳腺癌特异性死亡率（BCSM）之间的关联知之甚少。
在 1992 年至 2013 年期间，癌症预防研究-II 营养队列中有 5254 名女性被诊断为局部或区域性乳腺癌，其中有 1771 人死亡（505 人死于乳腺癌）。使用多变量 Cox 比例风险回归模型，根据诊断时的年龄（<65 岁，≥65 岁），研究了诊断前和诊断后体重指数（BMI）和中高强度体力活动（MET 小时/周）与死亡率结局之间的关系。
在诊断时年龄≥65 岁的女性（n=4226）中，诊断前和诊断后的 BMI（每 5kg/m）与 BCSM 的风险增加相关（诊断前，HR 1.27，95%CI 1.14-1.41；诊断后，HR 1.19，95%CI 1.04，1.36）；诊断前和诊断后体力活动均与 BCSM 无关。在诊断时年龄<65 岁的女性（n=1028）中，两个时间点的 BMI 与 BCSM 均无显著相关性；然而，诊断后体力活动与 BCSM 呈显著负相关趋势（P 趋势=0.01）。在两个年龄组中，BMI 和体力活动，无论何时评估，均与全因死亡率显著相关。
诊断前或诊断后较高的 BMI 与老年患者 BCSM 风险增加相关，独立于合并症和诊断时的分期。即使对于 65 岁或以上的女性，也应讨论体重管理问题，以降低 BCSM 发生率。
