BRCA1 mutation, leptin and estrogen levels in breast cancer patients.

Pre- and postmenopausal patients with breast cancer were screened for mutation of the BRCAI gene and estrogens and leptin levels were measured. In postmenopausal BRCA1 mutation carriers, leptin levels were significantly lower and correlated with the body mass index (BMI). No significant difference in leptin levels was revealed between pre- and postmenopausal patients. Our findings suggest the existence of an alternative mechanism responsible for carcinogenesis in breast cancer patients with a genetic background.