Breast cancer: biological characteristics in postmenopausal type 2 diabetic women. Identification of therapeutic targets.

Hypothesis: Epidemiological data have suggested a possible relationship between diabetes mellitus and cancer risk, particularly breast cancer. We set out to investigate the effect of diabetes mellitus on the expression of estrogen and progesteron receptors and on the proliferative activity of primary breast cancer.

Methods: We selected 77 diabetic women and 578 control patients all in post-menopause and diagnosed with primary breast cancer. All patients underwent surgical excision of the tumor and on the specimens were performed an assessment of estrogen receptor and progesteron receptor and proliferative activity assay by (3)H-Thymidine incorporation.

Results: Diabetic women showed a decreased proliferative activity, while having the same estrogen receptor and progesteron receptor status and mean cytoplasmic concentration of their receptors than control group. Insulin treated women had a lower proliferative activity than non-insulin treated ones.

Conclusion: Hyperinsulinemia and hyperglicemia influence in negative way the proliferative activity of diabetic women, likely inducing the expression of transforming growth factor beta, despite the high serum levels of Insulin-like growth factor and estrogen.