Abstract
Breast cancer is the most common cancer among women where it is associated with considerable morbidity and mortality. The aim of this study was to investigate the association between insulin, estradiol levels and body mass index (BMI) as risk factors for breast cancer. Methods: 80 women newly diagnosed with breast cancer stage I–III invasive breast cancer, were selected randomly and divided in two groups: 40 pre-menopausal aged 26–46 years and 40 post-menopausal aged 52–90 years. Radioimmunoassay used for serum insulin levels measurement, ELISA was used for estradiol levels and BMI calculated by weight (kg)/height (m2). Results: Insulin levels in premenopausal (16.6 ± 10.5) and postmenopausal (17.9 ± 8.8); breast cancer patients showed increasing pattern from the normal levels (4.0–16.0 μIU/ml). While, the levels of estradiol in premenopausal (233 ± 173) and postmenopausal, (549 ± 468); estradiol level in postmenopausal was higher than normal level (50–300 ng/ml), its level showed significantly increase in postmenopausal breast cancer (P.Value = 0.001). Conclusion: Insulin levels increased in pre- and post-menopausal breast cancer patients while estradiol levels do not showed association with premenopausal breast cancer. High BMI, high insulin and estradiol levels in post-menopausal women may be considered as risk factors for breast cancer.