Manchester Cancer Research Centre and NIHR Manchester Biomedical Research Centre, Manchester, UK.
Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
Br J Cancer. 2020 May;122(10):1552-1561. doi: 10.1038/s41416-020-0807-9. Epub 2020 Mar 23.
We tested the hypothesis that body mass index (BMI) aged 20 years modifies the association of adult weight gain and breast cancer risk.
We recruited women (aged 47-73 years) into the PROCAS (Predicting Risk Of Cancer At Screening; Manchester, UK: 2009-2013) Study. In 47,042 women, we determined BMI at baseline and (by recall) at age 20 years, and derived weight changes. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for new breast cancer using Cox models and explored relationships between BMI aged 20 years, subsequent weight changes and breast cancer risk.
With median follow-up of 5.6 years, 1142 breast cancers (post-menopausal at entry: 829) occurred. Among post-menopausal women at entry, BMI aged 20 years was inversely associated [HR per SD: 0.87 (95% CI: 0.79-0.95)], while absolute weight gain was associated with breast cancer [HR per SD:1.23 (95% CI: 1.14-1.32)]. For post-menopausal women who had a recall BMI aged 20 years <23.4 kg/m (75th percentile), absolute weight gain was associated with breast cancer [HR per SD: 1.31 (95% CIs: 1.21-1.42)], but there were no associations for women with a recall BMI aged 20 years of >23.4 kg/m (P values <0.05).
Adult weight gain increased post-menopausal breast cancer risk only among women who were <23.4 kg/m aged 20 years.
我们检验了一个假设，即 20 岁时的体重指数（BMI）会改变成年后体重增加与乳腺癌风险之间的关联。
我们招募了年龄在 47-73 岁之间的女性参加 PROCAS（预测筛查时癌症风险；英国曼彻斯特：2009-2013 年）研究。在 47042 名女性中，我们确定了基线时和（通过回忆）20 岁时的 BMI，并得出体重变化。我们使用 Cox 模型估计了新乳腺癌的风险比（HR）和 95%置信区间（CI），并探讨了 20 岁时的 BMI、随后的体重变化与乳腺癌风险之间的关系。
中位随访时间为 5.6 年，共发生 1142 例乳腺癌（入组时绝经后：829 例）。在入组时绝经后的女性中，20 岁时的 BMI 与乳腺癌呈负相关[每标准差的 HR：0.87（95%CI：0.79-0.95）]，而绝对体重增加与乳腺癌相关[每标准差的 HR：1.23（95%CI：1.14-1.32）]。对于 20 岁时 BMI<23.4kg/m（第 75 百分位数）的绝经后女性，绝对体重增加与乳腺癌相关[每标准差的 HR：1.31（95%CI：1.21-1.42）]，但对于 20 岁时 BMI>23.4kg/m 的女性没有关联（P 值<0.05）。
只有在 20 岁时 BMI<23.4kg/m 的女性中，成年后体重增加才会增加绝经后乳腺癌的风险。
