Physical activity has been found to be associated with decreased risk of breast cancer in postmenopausal women in the majority of epidemiologic studies, but the association is inconsistent in premenopausal women.
Berman Center for Outcomes and Clinical Research, Division of Clinical Epidemiology, Hennepin County Medical Center, Suite 440, 825 South 8th Street, Minneapolis, MN 55404, USA. margo006@umn.edu
