[Oral contraception and the risk of breast cancer]

The evaluation of carcinologic risks associated with various types of oral contraceptives remains unclear, because the constant evolution of composition and dosages in oestrogen and progestagen of pill. Since the oral contraceptives introduction 30 years ago, numerous epidemiological studies have analysed the association between OC and breast cancer risk. The recent meta-analysis of the Collaborative Group on Hormonal Factors in Breast Cancer provides large results. Original data from 54 studies representing about 90% of the published epidemiological studies were reanalyzed. The main findings are that is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. However, the cancers diagnosed in women who had used oral contraceptives are less advanced clinically than the cancers diagnosed in women who had not used them, suggesting a bias of screening in oral contraceptives users. However, the benefice-risk balance of OC is largely positive. The evaluation of third generation of pill is not yet available. Studies of third generation pill use and breast cancer risk are necessary.