[1110] Declining recurrence rates among DCIS patients treated with breast-conserving surgery in the community setting. Habel LA, Achacoso NS, Nekhlyudov L, Haque R, Schnitt S, Collins L, Acton LL, Fletcher S, Quesenberry CP.. Kaiser Permanente, Oakland, CA; Harvard Pilgrim Health Care, Boston, MA; Kaiser Permanente, Pasadena, CA; Beth Israel Deaconess Medical Center, Boston, MA Background: The aim of this analysis was to examine whether recurrence rates among DCIS patients treated with breast-conserving surgery have been changing over time and the extent to which use of adjuvant radiotherapy and tamoxifen are associated with these changes. Material and Methods: Cancer registries and electronic medical records were used to establish a cohort of DCIS patients diagnosed from 1990-2001 and treated with breast conserving surgery in three health plans. We excluded patients over age 84 years at initial DCIS diagnosis, those with a prior history of breast cancer (in situ or invasive), and those with bilateral disease at diagnosis. Medical records were reviewed to identify subsequent breast cancer events and to obtain additional information on clinical and patient factors. Recurrences were defined as a subsequent ipsilateral DCIS or invasive breast cancer or a regional/distant metastasis. We calculated the cumulative incidence of recurrence (overall and separately for invasive disease) at 5 years following diagnosis of the initial DCIS. Rates were also calculated for patients according to treatment (radiotherapy, tamoxifen). Results: We identified 3072 eligible patients; 362 (11.8%) of whom had a recurrence during a median follow-up of 3.0 years (range 0.5-13.3). The 5-year cumulative recurrence rate (DCIS or invasive disease) declined markedly over the study period, from 15.0% (95% CI 10.5-19.5) among patients diagnosed in 1990-91 to 8.7% (95% CI 6.4-11.0) in 1998-99. The 5-year cumulative incidence of an invasive recurrence decreased from 8.2% (95% CI 4.8-11.7) in 1990-91 to 3.6% (95% CI 2.1-5.1) in 1998-99. Use of adjuvant radiotherapy, increased from approximately 26% in 1990-91 to 59% in 1998-99, and use of adjuvant tamoxifen increased from 2.7% in 1990-91 to 19.8% in 1998-99. Rates during this period appeared to decline somewhat even after adjusting for or stratifying on these treatment factors. For example, among women who had neither adjuvant radiotherapy or hormonal therapy in the two periods, there was a suggestion of a slight decrease in recurrence (DCIS or invasive disease), from 17.9% (95% CI 12.2-23.7) in 1990-91 to 15.4% (95% CI 10.3-20.4) in 1998-99. Discussion: The marked increase in the 1990s in the use of adjuvant radiotherapy and/or hormonal therapy for DCIS patients treated with breast conserving therapy appears to be associated with substantially lower recurrence rates, though recurrence rates also appeared to fall somewhat in women not receiving these treatments, suggesting other protective factors are involved as well. These factors should be clarified. San Antonio Breast Cancer Symposium, 12/06 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.