WHI risks: Any relevance to menopause management?

Abstract 

Two randomised controlled trials of hormone therapy (HT) were conducted within the US Women's Health Initiative. Both were chronic disease prevention trials, undertaken to determine whether HT reduced cardiovascular risk and increased breast cancer risk. Because the majority of subjects in both trials were asymptomatic and many years postmenopausal, and because substantial numbers had received HT prior to recruitment to the trials, care must be taken in drawing conclusions that the observed risks are applicable to women for whom HT is conventionally prescribed. Each of the reported risks must be examined critically to determine its likely applicability to symptomatic women treated for two to three years to relieve symptoms, but sometimes for substantially longer periods. Further, the risks reported in each of the two trials must be considered separately.

Concerning cardiovascular disease, many subjects in the trials were at increased baseline risk because of their age, body mass index, smoking status, blood pressure and years since menopause, in contrast to the usual situation for symptomatic perimenopausal women. Therefore the reported overall cardiovascular risks in WHI, in both treatment arms, should be regarded as irrelevant to menopause management.

In contrast, breast cancer risk is relevant, providing that proper note is taken of the fact that there was no increased risk after five years of combined hormone therapy in non-prior HT users and there was a tendency to a decreased risk in oestrogen only treated individuals. Other risks are analysed similarly.

Keywords: Hormone therapy, Cardiovascular disease, Breast cancer, Venous thromboembolism, Dementia