Department of Medicine, University of North Carolina, Chapel Hill, 27599-7280, USA.
Cancer Causes Control. 2012 Jul;23(7):1193-203. doi: 10.1007/s10552-012-9989-7. Epub 2012 May 22.
Diabetes has been associated with increased risk of breast cancer in a number of epidemiologic studies, but its effects on survival among women diagnosed with breast cancer have been examined less frequently. Importantly, prior investigations have rarely considered the influence of factors associated with diabetes such as obesity, age at diabetes diagnosis, duration of diabetes, or diabetes treatments.
We evaluated the effect of self-reported diabetes on breast cancer incidence and mortality in the Long Island Breast Cancer Study Project, which includes 1,447 breast cancer cases and 1,453 controls. Follow-up data for all-cause (n = 395) and 5-year breast cancer-specific mortality (n = 104) through December 2005 were determined for case women from the National Death Index. Adjusted logistic regression and Cox proportional hazards models were used to estimate odds ratios (OR) and hazards ratios (HR), respectively.
Postmenopausal women with diabetes were at increased risk of developing breast cancer [OR = 1.35; 95 % confidence interval (CI) = 0.99-1.85], as were those who were not of white race regardless of menopausal status [OR = 3.89; 95 % CI = 1.66-9.11]. Among case women, diabetes was associated with a modestly increased risk of death from all causes [HR = 1.65; 95 % CI = 1.18-2.29], an association that was stronger in women who were obese at breast cancer diagnosis [HR = 2.49; 94 % CI = 1.58-3.93]. In analyses restricted to diabetics, there was no statistically significant effect of duration of diabetes or type of treatment on breast cancer incidence or mortality.
Our findings suggest that diabetes may increase incidence of breast cancer in older women and non-whites, and mortality due to all causes.
多项流行病学研究表明，糖尿病会增加罹患乳腺癌的风险，但糖尿病对乳腺癌患者生存的影响却鲜有研究。重要的是，既往研究很少考虑到与糖尿病相关的因素的影响，如肥胖、糖尿病诊断时的年龄、糖尿病的持续时间或糖尿病的治疗。
我们评估了长岛乳腺癌研究项目中自我报告的糖尿病对乳腺癌发病率和死亡率的影响，该项目包括 1447 例乳腺癌病例和 1453 例对照。通过国家死亡索引确定了病例女性所有原因（n=395）和 5 年乳腺癌特异性死亡率（n=104）的随访数据，随访截止日期为 2005 年 12 月。采用调整后的逻辑回归和 Cox 比例风险模型分别估计比值比（OR）和风险比（HR）。
绝经后女性患有糖尿病，罹患乳腺癌的风险增加（OR=1.35；95%置信区间（CI）=0.99-1.85），无论绝经状态如何，非白种人女性也是如此（OR=3.89；95%CI=1.66-9.11）。在病例女性中，糖尿病与全因死亡风险轻度增加相关（HR=1.65；95%CI=1.18-2.29），在乳腺癌诊断时肥胖的女性中这种相关性更强（HR=2.49；94%CI=1.58-3.93）。在仅针对糖尿病患者的分析中，糖尿病的持续时间或治疗类型对乳腺癌发病率或死亡率没有统计学上的显著影响。
我们的研究结果表明，糖尿病可能会增加老年女性和非白种人罹患乳腺癌的风险，以及全因死亡率。
