[Contraception and breast cancer].

The role of oral contraceptives in the development of breast cancer has given rise and still gives rise to many debates, accentuated by the economic and social impact of contraception. Several problems can the brought forward: can oral contraceptives (OC) play a role in the development of breast cancer? Can they aggravate it? Can they prevent it? We have various means at our disposal to help us in answering those difficult questions: fundamental studies, mechanisms of action of steroid hormones in the development of the mammary gland, comprehension of the mechanisms of carcinogenesis, epidemiological studies which enable us to define the notion of relative risk. At present, there is no emergence of the notion of an aggravation of the risk of breast cancer linked with the intake of oral contraceptives. However, it must be reminded that the use of oral contraceptives is still recent if we take into account the existence of a latency period before an eventual harmful effect appears and the fact that the oestro-progestative compositions have been greatly modified in those last few years. However, the present studies are centred on the populations said to be "at risk". The results of studies on women who have taken an OC before their first pregnancy or before the age of 25 still remain contradictory. Those of women with a family history of breast cancer or hyperplastic lesions are reassuring but need to be confirmed. Finally, a protective effect of a contraceptive composition is yet to be demonstrated.