Bad Breast Cancer on the Rise in Young Women

In women aged 25 to 39, the incidence of stage IV disease has increased, on average, 2.07% per year from 1976 to 2009; no similar trend was observed in older women.

A new report analyzing the U.S. National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database suggests that the incidence of de novo metastatic (stage IV) breast cancer in young women is increasing. To identify this trend, investigators obtained data on breast cancer incidence, incidence trends, and survival rates as a function of age and extent of disease at diagnosis from three SEER registries spanning the years 1973 to 2009, 1992 to 2009, and 2000 to 2009.

The incidence of stage IV breast cancer at diagnosis for young women (aged 25 to 39) increased from 1.53 per 100,000 (95% confidence interval, 1.01–2.21) in 1976 to 2.90 per 100,000 (95% CI, 2.31–3.59) in 2009. This difference represents an absolute increase of 1.37 per 100,000 during the 34-year interval, or an average compounded increase of 2.07% per year (95% CI, 1.57%–2.58%; P<0.001). The incidence of stage IV disease in young women increased among all races and ethnicities evaluated, especially blacks and non-Hispanic whites, in both metropolitan and nonmetropolitan areas, and increased more for those with estrogen receptor–positive versus estrogen receptor–negative subtypes. In contrast, women in this age group did not experience similar increases in localized or regional disease. Women aged 40 to 54 also experienced a significant increase in stage IV disease, but all of the increases occurred before 1990, and no other age groups experienced significant increases in local, regional, or stage IV disease during the study period.

CITATION(S):

Johnson RH et al. Incidence of breast cancer with distant involvement among women in the United States, 1976 to 2009. JAMA 2013 Feb 27; 309:800.