Since the first publication of results from the randomized controlled trial by the Women’s Health Initiative (WHI) , consumption of menopausal hormone therapy (MHT) has decreased in most countries . Several studies have reported a coincidental decrease in incidence of breast cancer (BC), but the extent of this decrease and the length of time between the drop in MHT use and the change in BC incidence have varied between countries . This may reflect differences between studies, in BC incidence, in MHT use (prevalence of use and regimens used), in confounding factors (i.e. BC screening), but also in study methodology.
We recently published the results of a study, ‘Menopausal hormone therapy use in relation to BC incidence in 11 European countries’, whose aim was to analyze the changes in BC incidence and MHT use, using the same methodology . BC incidence data were provided from cancer registries, and MHT sales data were extracted from health sales databases for the years 2003 to 2013.
The changes in BC incidence varied widely between the countries. There was an increase in some countries, a decrease in others and no change in the remainder. Conversely, for MHT sales, the drop was consistent in all countries for the whole period of follow-up, varying between 42.1% and 76%. We found no statistical evidence of an association between BC incidence and MHT sales in the past year (p = 0.60).
Caroline Antoine and Serge Rozenberg
OBGYN Department, Menopause Clinic, CHU Saint-Pierre (ULB/VUB), Brussels, Belgium