Risk factors of breast cancer in a sample of Kurdish women of Kurdistan region - Iraq: A comparative study between pre-menopausal and post-menopausal women

Abstract

Background and objectives: To evaluate the difference between pre- and post-menopausal breast cancer regarding menstrual and reproductive risk factors for ca breast.. Methods: A prospective case-control study was conducted in Nanakaly Oncology Hospital in Erbil city-Kurdistan- Iraq, between September 2009 and April 2011. Cases were breast cancer patients admitted in the oncology floor of the hospital. Controls were hospital pa-tients without breast cancer (other cancers). The study enrolled 300 cases and 600 con-trols. Menstrual and reproductive history was taken from both the cases and the controls. For every risk factor age-adjusted odds ratio (OR) and 95% confidence interval (CI) was calculated by logistic regression analysis, separate for pre- and post-menopausal women . Results: Among the breast cancer patients, 42.7% were pre-menopausal and 57.3% were post-menopausal. Age at menarche had no association with breast cancer for both pre- and post-menopausal women. Nulliparity was a risk factor for both pre-menopausal (OR = 2.42, 95% CI (1.1-4.6) and post-menopausal breast cancer (OR = 3.7, 95% CI (2.04-6.87)). Among parous women only post-menopausal females having <3 children were at in-creased risk for breast cancer (OR = 2.18, 95% CL (1.45-3.27) compared with females having > 3 children. Younger age at first live birth decreased breast cancer risk in both pre- and post-menopausal women. Breastfeeding was not associated with both pre- and post-menopausal breast cancer.Conclusion: Majority of risk factors for pre-menopausal breast cancer are also associated with post-menopausal breast cancer except less parity, which increased the risk for post-menopausal breast cancer only.