Charlot Marjory, Castro-Webb Nelsy, Bethea Traci N, Bertrand Kimberly, Boggs Deborah A, Denis Gerald V, Adams-Campbell Lucile L, Rosenberg Lynn, Palmer Julie R
Section of Hematology and Oncology, Department of Medicine, Evans Biomed Research Center, Boston University School of Medicine, 650 Albany Street, Suite 406, Boston, MA, 02118, USA.
Slone Epidemiology Center, Boston University, Boston, MA, USA.
Cancer Causes Control. 2017 Jan;28(1):61-67. doi: 10.1007/s10552-016-0837-z. Epub 2016 Dec 19.
Breast cancer mortality is higher in Black women than in White women. The prevalence of type 2 diabetes mellitus is also higher, yet data on whether diabetes affects breast cancer mortality in this population are lacking. We investigated the relation of diabetes at the time of breast cancer diagnosis to breast cancer mortality in the Black Women's Health Study, a prospective cohort study.
1,621 Black women with invasive breast cancer diagnosed in 1995-2013 were followed by mailed questionnaires and searches of the National Death Index. Multivariable Cox regression analysis was used to compute hazard ratios (HRs) for diabetes in relation to breast cancer mortality and all-cause mortality, with adjustment for age, stage, treatment modality, estrogen receptor (ER) status, and body mass index.
There were 368 deaths during follow-up, of which 273 were due to breast cancer. Breast cancer mortality was significantly increased in women who had been diagnosed with diabetes at least 5 years before breast cancer occurrence, HR 1.86 (95% CI 1.20-2.89), with elevations observed for both ER+ and ER- breast cancer. All-cause mortality was also higher in diabetics, with HRs of 1.54 (95% CI 1.12-2.07) overall and 2.26 (95% CI 1.62-3.15) for ≥5-year duration of diabetes relative to non-diabetics.
Our results present the first solid evidence of a positive association of type 2 diabetes with breast cancer mortality in Black women. Given the higher prevalence and earlier onset of type 2 diabetes in Black women, it is likely that diabetes contributes to racial disparities in breast cancer mortality.
黑人女性的乳腺癌死亡率高于白人女性。2型糖尿病的患病率在黑人女性中也更高，但缺乏关于糖尿病是否影响该人群乳腺癌死亡率的数据。我们在一项前瞻性队列研究——黑人女性健康研究中，调查了乳腺癌诊断时糖尿病与乳腺癌死亡率之间的关系。
对1995年至2013年诊断为浸润性乳腺癌的1621名黑人女性进行随访，通过邮寄问卷和查询国家死亡指数。多变量Cox回归分析用于计算糖尿病与乳腺癌死亡率和全因死亡率相关的风险比（HRs），并对年龄、分期、治疗方式、雌激素受体（ER）状态和体重指数进行调整。
随访期间有368例死亡，其中273例死于乳腺癌。在乳腺癌发生前至少5年被诊断为糖尿病的女性中，乳腺癌死亡率显著增加，HR为1.86（95%CI 1.20-2.89），ER+和ER-乳腺癌均有升高。糖尿病患者的全因死亡率也更高，总体HR为1.54（95%CI 1.12-2.07），糖尿病病程≥5年的患者相对于非糖尿病患者的HR为2.26（95%CI 1.62-3.15）。
我们的结果首次提供了2型糖尿病与黑人女性乳腺癌死亡率呈正相关的有力证据。鉴于黑人女性中2型糖尿病的患病率较高且发病较早，糖尿病很可能导致了乳腺癌死亡率的种族差异。
