Influence of diabetes mellitus type 2 and prolonged estrogen exposure on risk of breast cancer among women in Armenia.

Diabetes mellitus type 2 (DM2) and breast cancer (BrCa) are prevalent in Armenia. We investigated DM2, reproductive factors, and BrCa in a case control study of 302 women. Multiple logistic regression analyses revealed DM2 increased adjusted odds of BrCa by 5.53 (95% CI 1.34-22.81). Any birth was protective (adjusted OR=0.36, 95% CI 0.20-0.66). Each year delay in first pregnancy increased risk (adjusted OR=1.13, 95% CI 1.01-1.27) as did induced abortions (adjusted OR=2.86, 95% CI 1.02-8.04). Odds ratios were adjusted for age and body mass index (BMI), which confounded associations between DM2 and BrCa. We suggest our findings imply the need for further investigation in Armenian and in other populations with similar characteristics.