Study Finds Small Increase in Incidence of Advanced Breast Cancer Among Younger Women
An analysis of breast cancer trends in the U.S. finds a small but statistically significant increase in the incidence of advanced breast cancer for women 25 to 39 years of age, without a corresponding increase in older women, according to a study appearing in the Journal of the American Medical Association.
"In the United States, breast cancer is the most common malignant tumor in adolescent and young adult women 15 to 39 years of age, accounting for 14 percent of all cancer in men and women in the age group. The individual average risk of a woman developing breast cancer in the United States was 1 in 173 by the age of 40 years when assessed in 2008. Young women with breast cancer tend to experience more aggressive disease than older women and have lower survival rates. Given the effect of the disease in young people and a clinical impression that more young women are being diagnosed with advanced disease, we reviewed the national trends in breast cancer incidence in the United States," the authors write.
Rebecca H. Johnson, M.D., of Seattle Children's Hospital and University of Washington, Seattle, and colleagues conducted a study in which breast cancer incidence, incidence trends, and survival rates as a function of age and extent of disease at diagnosis were obtained from 3 U.S. National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) registries. These registries provide data spanning 1973-2009, 1992-2009, and 2000-2009. SEER defines localized as disease confined to the breast, regional to contiguous and adjacent organ spread (e.g., lymph nodes, chest wall), and distant disease to remote metastases (bone, brain, lung, etc).
Since 1976, there has been a steady increase in the incidence of distant disease breast cancer in 25- to 39-year-old women, from 1.53 per 100,000 in 1976 to 2.90 per 100,000 in 2009. The researchers note that this is an absolute difference of 1.37 per 100,000, representing an average compounded increase of 2.07 percent per year over the 34-year interval, a relatively small increase, "but the trend shows no evidence for abatement and may indicate increasing epidemiologic and clinical significance."