JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, SAR, China.
Department of Oncology, Princess Margaret Hospital, Kwai Chung, Hong Kong, SAR, China.
Horm Cancer. 2020 Aug;11(3-4):191-199. doi: 10.1007/s12672-020-00386-2. Epub 2020 Jun 3.
Previous studies reported heterogeneous associations between obesity and reproductive-related breast cancer risk factors and breast cancer intrinsic subtypes; however, few studies have been conducted in Asian populations. Here, we aimed to examine whether risks associated with established breast cancer risk factors varied by breast cancer subtypes in Chinese women. We conducted a hospital-based case-control study in Hong Kong, including a total of 2169 Chinese women. Unconditional polytomous logistic regression models were used to calculate adjusted odds ratios (AORs) and 95% confidence intervals(95%CIs) to estimate relative risks associated with examined risk factors in case-control analyses and to test for heterogeneity across breast cancer subtypes in case-case analyses. In case-case analyses, compared with luminal A patients, luminal B (AOR = 1.76, 95% CI = 1.07-2.88), HER2 overexpressing (AOR = 3.40, 95% CI = 1.56-7.39), and triple negative (TNBC, AOR = 2.39, 95% CI = 1.18-4.82) patients were more likely to be postmenopausal. In case-control analyses, reduced risks associated with parity and younger age at first birth were only seen for luminal A and B cases especially among postmenopausal women, whereas having ≥ 3 children was associated with increased risk for HER2 overexpressing and TNBC among premenopausal women. Obesity was associated with increased risk for all subtypes. We found heterogeneous associations between parity-related risk factors by menopausal status and breast cancer subtypes among Chinese patients, which is similar to those observed in Western populations. Interestingly, obesity was associated with increased breast cancer risk regardless of menopausal status or subtypes, except for premenopausal luminal patients, which appears to be unique in Asian populations.
先前的研究报告称，肥胖与生殖相关乳腺癌风险因素和乳腺癌内在亚型之间的关联存在异质性；然而，在亚洲人群中进行的此类研究较少。在此，我们旨在研究在中国女性中，与已确定的乳腺癌风险因素相关的风险是否因乳腺癌亚型而异。我们在香港进行了一项基于医院的病例对照研究，共纳入 2169 名中国女性。我们使用条件多项逻辑回归模型计算调整后的优势比（AOR）和 95%置信区间（95%CI），以在病例对照分析中估算与所检查的风险因素相关的相对风险，并在病例-病例分析中检验乳腺癌亚型之间的异质性。在病例-病例分析中，与 luminal A 型患者相比，luminal B 型（AOR=1.76，95%CI=1.07-2.88）、HER2 过表达型（AOR=3.40，95%CI=1.56-7.39）和三阴性乳腺癌（TNBC，AOR=2.39，95%CI=1.18-4.82）患者更有可能处于绝经后状态。在病例对照分析中，仅在 luminal A 和 B 型病例中，较低的生育次数和首次生育年龄与绝经后妇女相关，而生育≥3 个孩子与绝经前妇女中 HER2 过表达和 TNBC 风险增加相关。肥胖与所有亚型的风险增加相关。我们发现，在中国患者中，与生育相关的风险因素与绝经状态和乳腺癌亚型之间存在异质性关联，这与西方人群中的观察结果相似。有趣的是，肥胖与乳腺癌风险增加相关，与绝经状态或亚型无关，除了绝经前 luminal 型患者，这在亚洲人群中似乎是独特的。
