[Treatment of the menopause: estrogens and breast cancer].

The responsibility of oestrogens in the aetiology and development of cancer of the breast is critically discussed. There are in fact perfectly contradictory theoretical and clinical arguments. The work of epidemiologists and biologists results in no less heterogeneous results. It is possible that oestrogens may be incapable of inducing the development of cancer of the breast, but it is very probable that the oestrogens are capable of accelerating the development of a quiescent tumour of small volume. The lesion is clinically and radiologically undetectable.