Slone Epidemiology Center at Boston University, Boston, MA, USA.
Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, USA.
Int J Epidemiol. 2022 Jan 6;50(6):1936-1947. doi: 10.1093/ije/dyab165.
The history of gestational diabetes mellitus (GDM) has been associated with breast cancer risk in some studies, particularly in young women, but results of cohort studies are conflicting.
We pooled data from 257 290 young (age <55 years) women from five cohorts. We used multivariable Cox proportional-hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between GDM history and risk of breast cancer, overall and by oestrogen receptor (ER) status, before age 55 years, adjusted for established breast cancer risk factors.
Five percent of women reported a history of GDM and 6842 women reported an incident breast-cancer diagnosis (median follow-up = 16 years; maximum = 24 years). Compared with parous women without GDM, women with a history of GDM were not at increased risk of young-onset breast cancer overall (HR = 0.90; 95% CI: 0.78, 1.03) or by ER status (HR = 0.96; 95% CI: 0.79, 1.16 for ER-positive; HR = 1.07; 95% CI: 0.78, 1.47 for ER-negative). Compared with nulliparous women, parous women with a history of GDM had a lower risk of breast cancer overall (HR = 0.79; 95% CI: 0.68, 0.91) and of ER-positive (HR = 0.82; 95% CI: 0.66, 1.02) but not ER-negative (HR = 1.09; 95% CI: 0.76, 1.54) invasive breast cancer. These results were consistent with the HRs comparing parous women without GDM to nulliparous women.
Results of this analysis do not support the hypothesis that GDM is a risk factor for breast cancer in young women. Our findings suggest that the well-established protective effect of parity on risk of ER-positive breast cancer persists even for pregnancies complicated by GDM.
一些研究表明，妊娠期糖尿病（GDM）病史与乳腺癌风险相关，尤其是在年轻女性中，但队列研究的结果存在矛盾。
我们汇总了来自五个队列的 257290 名年轻（<55 岁）女性的数据。我们使用多变量 Cox 比例风险回归来估计 GDM 病史与乳腺癌风险之间的关联的风险比（HR）和 95%置信区间（CI），总体以及在 55 岁之前按雌激素受体（ER）状态进行分层，调整了已确定的乳腺癌风险因素。
5%的女性报告有 GDM 病史，6842 名女性报告了乳腺癌的发病（中位随访时间为 16 年；最长随访时间为 24 年）。与无 GDM 的多产妇相比，GDM 病史的女性总体上年轻乳腺癌的发病风险没有增加（HR=0.90；95%CI：0.78，1.03）或按 ER 状态分层（HR=0.96；95%CI：0.79，1.16 为 ER 阳性；HR=1.07；95%CI：0.78，1.47 为 ER 阴性）。与未产妇相比，有 GDM 病史的多产妇总体上乳腺癌发病风险较低（HR=0.79；95%CI：0.68，0.91）和 ER 阳性（HR=0.82；95%CI：0.66，1.02），但 ER 阴性（HR=1.09；95%CI：0.76，1.54）浸润性乳腺癌发病风险无差异。这些结果与将无 GDM 的多产妇与未产妇进行比较的 HR 结果一致。
本分析结果不支持 GDM 是年轻女性乳腺癌的危险因素这一假说。我们的研究结果表明，多产对 ER 阳性乳腺癌风险的明确保护作用即使在伴有 GDM 的妊娠中也仍然存在。
