ABSTRACT
The totality of experimental and epidemiological evidence that ovarian hormones cause breast cancer is sufficiently compelling that epidemiologists are increasingly focused on using the data to develop prevention strategies. Cell division is necessary for the series of genetic changes required for a cell to undergo transformation from normal to a fully malignant phenotype. Breast cancer is characterized by a series of risk factors that emphasize the importance of ovarian steroid hormones in breast cancer etiology. Based on the established effects of oophorectomy in reducing breast cancer risk, Pike, colleagues proposed that the induction of a medical menopause in premenopausal women would result in a substantial reduction in breast cancer incidence. Although hormonal chemoprevention of breast cancer is increasingly promising, there is clearly a need for prevention strategies for breast cancer via life-style change. Although precise age at natural menopause is often difficult to recall in epidemiological studies, ages at natural versus surgical menopause have roughly effects on breast cancer risk.
