Wednesday, April 04, 2012
Link Between an Injectable Contraceptive and Breast Cancer Risk in Young Women Discovered
The first large-scale U.S.-based study to evaluate the link between an injectable form of progestin-only birth control and breast cancer risk in young women has found that recent use of a year or more doubles the risk. The results of the study, led by breast cancer epidemiologist Christopher I. Li, M.D., Ph.D., of Fred Hutchinson Cancer Research Center, are published online ahead of the April 15 print issue of Cancer Research.
While the contraceptive, called depo-medroxyprogesterone acetate, or DMPA, contains the same kind of progestin as the menopausal hormone-therapy regimen found by a Women’s Health Initiative clinical trial to increase breast cancer risk among postmenopausal women, few studies have evaluated the link between DMPA use and breast cancer risk in younger women.
“While DMPA is widely used by women throughout the world, there are limited data on the association between DMPA and breast cancer incidence,” said Li, a member of the Hutchinson Center’s Public Health Sciences Division. “Our study adds to the body of knowledge from international studies conducted in a diverse group of countries – Kenya, New Zealand, Thailand, Mexico and Costa Rica – which have shown that one of the risks associated with DMPA use may be an increased risk of breast cancer,” he said.