The Decrease in Breast-Cancer Incidence in 2003 in the United States
Ravdin, Peter M; Cronin, Kathleen A; Howlader, Nadia; Berg, Christine D; Chlebowski, Rowan T; Feuer, Eric J; Edwards, Brenda K; Berry, Donald A
19 April 2007
New England Journal of Medicine
1670
Volume 356; Issue 16; ISSN: 00284793
© 2007 New England Journal of Medicine. Provided by ProQuest Information and Learning. All Rights Reserved.
An initial analysis of data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries shows that the age-adjusted incidence rate of breast cancer in women in the United States fell sharply (by 6.7%) in 2003, as compared with the rate in 2002. Data from 2004 showed a leveling off relative to the 2003 rate, with little additional decrease. Regression analysis showed that the decrease began in mid-2002 and had begun to level off by mid-2003. A comparison of incidence rates in 2001 with those in 2004 (omitting the years in which the incidence was changing) showed that the decrease in annual age-adjusted incidence was 8.6% (95% confidence interval [CI], 6.8 to 10.4). The decrease was evident only in women who were 50 years of age or older and was more evident in cancers that were estrogen-receptor-positive than in those that were estrogen-receptor-negative.
The decrease in breast-cancer incidence seems to be temporally related to the first report of the Women's Health Initiative and the ensuing drop in the use of hormone-replacement therapy among postmenopausal women in the United States. The contributions of other causes to the change in incidence seem less likely to have played a major role but have not been excluded.N Engl J Med 2007;356:1670-4.
Copyright © 2007 Massachusetts Medical Society. All rights reserved.