The impact of oral contraceptive use on breast cancer risk: State of the art and future perspectives in the era of 4P medicine.

Breast cancer is the most commonly occurring cancer in women, the second most frequent cancer overall, and it causes the greatest number of cancer-related deaths among women. The significant increased concern of breast cancer worldwide may be attributed to the prolonged life expectancy and the adoption of the western lifestyle with its related risks factors. A woman's risk for breast cancer is linked to her reproductive history and with her lifetime hormonal exposure. Among the known risk factors for breast cancer, several studies investigated the possible role of the assumption of hormonal "pills" in both breast cancer incidence and development. Nevertheless, data about the association between the assumption of oral contraceptives and breast cancer incidence are still controversial and not conclusive. Given the public health importance of breast cancer and the popularity of hormonal "pills" as contraceptive, the impact of oral contraceptive use on breast cancer risk assumes relevance from both a clinical and a social point of view. Therefore, in this review we wanted to illustrate this issue by addressing the following major themes: a) the role of sex steroid hormones in female breast development and carcinogenesis; b) the clinical impact of hormonal oral contraception according to the state of the art literature; c) the actual scientific debate and future perspectives.