CDC Reports a Decrease in the Incidence of Breast Cancer

Although breast cancer is the most commonly diagnosed cancer in U.S. women, the Centers for Disease Control and Prevention (CDC) reports that the incidence of breast cancer has decreased since 1999. Data from population-based cancer registries show that invasive breast cancer decreased annually between 1999 and 2003; and, after increasing between 1999 and 2002, noninvasive breast cancer decreased between 2002 and 2003.

Data were collected from the CDC's National Program of Cancer Registries and the National Cancer Institute's Surveillance, Epidemiology, and End Results program. The largest decline occurred between 2002 and 2003 (6.1 percent for invasive disease and 2.7 percent for non-invasive disease). The decrease in breast cancer occurred across several age, cancer stage, and racial groups, with the most significant decrease occurring in women 50 years and older. Factors that may have contributed to the decrease in breast cancer include mammography screening, a decrease in the use of hormone therapy, and differences in risk-factor prevalence, diet, and lifestyle.