[5] A sharp decrease in breast cancer incidence in the United States in 2003. Ravdin PM, Cronin KA, Howlander N, Chlebowski RT, Berry DA.. MD Anderson; National Cancer Institute; Harbor UCLA Medical Center Introduction: The epidemiology of breast cancer may provide useful insights into risk factors for this disease, and the impact of various interventions on this disease's incidence and mortality. Modeling efforts, such as those of the Cancer Intervention and Surveillance Modeling Network (CISNET) have provided insight into the relative impact of screening and adjuvant therapy on these endpoints (NEJM 353:1784-1792,2005). Although randomized clinical trials such as those investigating the impact of hormone therapy, diet, and exercise provide the strongest evidence as to the influence of these factors, epidemiologically based models, particularly when there is a large change in these factors, may allow additional insights. Methods: SEER public use data from 1990 to the end of 2003 was used in these analyses. Results: Breast cancer incidence in the United States gradually increased at 1.7% per year from 1990 to 1998. Between 1998 and 2003 incidence began to decrease at 1% per year. In 2003 there was a 7% decrease in incidence within a single year. This marked decrease was seen both for in situ cancers (5.5%) and malignant cancers (7.3%). In order to gain additional insight as the possible reasons for the decline in incidence of breast cancer we conducted further subset analyses. The steep decline seemed to begin in early 2003 with relative rates (compared to a 2000/2001) showing a 1% decline in the first and second halves of 2002, 6% in the first half of 2003, and 9% in the second half of the year. The decline in incidence in 2003 relative to 2000/2001 was most evident in patients older than 50 (a 1%, 11%, 11%, and 7% decline in incidence for women in their 40's, 50's, 60's, and 70's respectively). The decline in incidence in ER positive invasive tumors was greater than ER negative tumors (8% versus 4%). When the analysis was restricted to patients 50-69 years of age this difference in decline in the incidence by ER was more striking (12% versus 4%). Conclusions: In 2003 a steep decrease in the incidence of breast cancer occurred in the United States. This decrease was most evident in patients older than 50, and largely occurred because of a decrease in the incidence of estrogen receptor positive breast cancer. Trends in use of hormone therapy (which decreased markedly in late 2002 following the publication of Women's Health Initiative results) and other medications potentially linked to breast cancer risk will be discussed in this context. San Antonio Breast Cancer Symposium, 12/06 Ann's NOTE: This created the BIGGEST media buzz at the conference. We all want to see what happens for 2004. Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.