Invasive Breast Cancer Risk Dropping in Young U.S. Women
At same time, increased risk of localized breast cancer and greater mammogram use
FRIDAY, Sept. 1 (HealthDay News) -- The risk of invasive breast cancer appears to be dropping for young women in the United States, despite an increase in rates of in situ breast cancer, according to a report in the September issue of Epidemiology.
Robert E. Tarone, Ph.D., of the International Epidemiology Institute in Rockville, Md., analyzed trends in breast cancer rates in American women aged 20 to 49 between 1975 and 2003.
The rates of invasive breast cancer dropped for women under 50, even though in situ breast cancer rates went up after 1980, paralleling the greater reliance on mammograms, the researcher reports. This decline suggests a drop in the risk of invasive breast cancer in repeated birth cohorts of women since 1945.
"Invasive breast cancer incidence rates are not increasing in young U.S. women despite increases in mammography and trends in known risk factors (e.g., reproductive factors) that would predict increasing risk," the authors conclude.