Hospital volume differences and five-year survival from breast cancer.

OBJECTIVES: The purpose of this study was to determine the effect of hospital volume on long-term survival for women with breast cancer. METHODS: Survival analysis and proportional-hazard modeling were used to assess 5-year survival and risk of death, adjusting for clinical and sociodemographic variables. RESULTS: At 5 years, patients from very low-volume hospitals had a 60% greater risk of all-cause mortality than patients from high-volume hospitals. CONCLUSIONS: Hospital volume of breast cancer surgical cases has a strong positive effect on 5-year survival. Research is needed to identify whether processes of care, especially postsurgical adjuvant treatments, contribute to survival differences.