TREATMENT DIFFERENCES AND OTHER PROGNOSTIC FACTORS RELATED TO BREAST-CANCER SURVIVAL - DELIVERY SYSTEMS AND MEDICAL OUTCOMES

Objective.-To determine differences in and relative importance of trea tment modalities by hospital type and their effect on survival of brea st cancer patients. Design.-Cohort of population-based cancer registry breast cancer patients diagnosed from 1984 through 1990. The analysis was done within this cohort, stratified by hospital type and treatmen t modality. Setting.-Orange County, California, residents diagnosed an d treated for breast cancer in 126 hospitals (small community, large c ommunity, health maintenance organization [HMO], or teaching). Patient s.-A total of 5892 non-Hispanic white women with no known prior cancer and with localized or regional, histologically confirmed breast cance r. Main Outcome Measures.-Effects of treatment modality and hospital t ype on survival. Adjustments for differences in age, tumor size, numbe r of positive lymph nodes, and histology were included in the analysis . Results.-Use of recommended breast-conserving surgery (BCS) was grea test among teaching hospitals, where more than 50% of patients with lo calized disease received BCS between 1988 and 1990 and 40% to 50% with regional disease received BCS between 1984 and 1990. At nonteaching h ospitals, 30% or less of patients received BCS between 1984 and 1989, regardless of stage. Rates of survival after BCS were at least as good as rates of survival after total mastectomy, other factors being equa l. Survival rates varied by hospital type for patients with localized disease, with significantly better rates at large community hospitals and significantly worse rates at HMO hospitals in comparison with smal l hospitals. Patients with regional disease at large hospitals had a s ignificant survival advantage. Conclusions.-Greater use of BCS is stro ngly urged. Overall, large community hospitals had significantly bette r survival rates than small community and HMO hospitals. Further follo w-up will determine if treatment and survival differences by hospital type persist.