Cancer risk of hormone replacement treatment in the menopause

For the last 40 years oestrogens have been prescribed for treating the menopause and their effects are beginning to be well recognised. Many epidemiological surveys have shown that giving oestrogens by themselves increases the risk of cancer of the endometrium. This most undesirable secondary effect can be neutralised if progestogens are given at the same time. It is even possible to treat endometrial hyperplasia, the precursor stage of cancer of the endometrium. No effects on cancers of the ovary, of the cervix, of the vagina and of the vulva have been found resulting from the use of replacement oestrogens. The epidemiological surveys to study the risk of cancer of the breast linked with oestrogen treatment have not shown that there is any increased risk. There are, however, still some doubts about sub-groups and in particular those women whose ovaries have been removed. As with cancer of the endometrium, taking progestogens at the same time lessens the risk, doubtless because the deficiency in progesterone is more important as a causative agent for the development of tumours in the breast than excess oestrogens. It is necessary to weigh the risks and the benefits of hormone replacement therapy after the menopause, but overall the results of studies that have been carried out until now favour greatly the prescription of such therapy.