Drop in Breast Cancer Rates Linked to Less Hormone Use
Decline in invasive breast cancers not attributed to fewer mammograms
WEDNESDAY, Aug. 15 (HealthDay News) -- Falling invasive breast cancer rates coincide with a sharp drop in postmenopausal hormone use and are probably not connected to a modest decline in routine mammograms, according to a report published online Aug. 14 in the Journal of the National Cancer Institute.
Karla Kerlikowske, M.D., of the San Francisco Veterans Affairs Medical Center in San Francisco, Calif., and colleagues analyzed 603,411 routine mammogram results involving 50- to 69-year-old women between 1997 and 2004 in four U.S. screening registries, including 3,238 women diagnosed with breast cancer up to a year later.
The researchers found that postmenopausal hormone use dropped 7 percent from 2000 to 2002, and 34 percent from 2002 to 2003. Ductal carcinoma in situ rates remained consistent; invasive cancer rates fell 5 percent annually from 2000 to 2003; estrogen receptor-positive invasive breast cancer rates dropped 13 percent between 2001 and 2003.
"Our finding of a statistically significant decline in the rate of estrogen receptor-positive invasive breast cancer in a screening mammography population after the start of a concomitant substantial decline in postmenopausal hormone therapy use suggests that a decline in screening mammography rates is unlikely to account for the recent decline in U.S. breast cancer incidence," the authors write.