Influence of hospital procedure volume on outcomes following surgery for colon cancer

Context Survival following high-risk cancer surgery, such as pancreatectomy and esophagectomy, is superior at hospitals where high volumes of these pr ocedures are per formed. Conflicting evidence exists as to whether the asso ciation between hospital experience and favorable health outcomes also appl ies to more frequently performed operations, such as those for colon cancer . Objective To determine whether hospital procedure volume predicts survival following colon cancer surgery. Design, Setting, and Participants Retrospective cohort study of data from t he Surveillance, Epidemiology and End Results-Medicare linked database on 2 7986 colon cancer patients aged 65 years and older who had surgical resecti on for primary adenocarcinoma diagnosed between 1991 and 1996. Main Outcome Measures Thirty-day postoperative mortality and overall and ca ncer-specific long-term survival, by hospital procedure volume. Results We found small differences in 30-day postoperative mortality for pa tients treated at low- vs high-volume hospitals (3.5% at hospitals in the t op-volume quartile vs 5.5% at hospitals in the bottom-volume quartile). How ever, the correlation was statistically significant and persisted after adj usting for age at diagnosis, sex, race, cancer stage, comorbid illness, soc ioeconomic status, and acuity of hospitalization (P<.001). The association was evident for subgroups with stage I, II, and III disease. Hospital Volum e directly correlated with survival beyond 30 days and also was not attribu table to differences in case mix (P<.001). The association between hospital volume and long-term survival was concentrated among patients with stage I I and III disease (P<.001 for both). Among stage III patients. Variation in use of adjuvant chemotherapy did not explain this finding. Conclusion Our data suggest that hospital procedure volume predicts clinica l outcomes following surgery for colon cancer, although the absolute magnit udes of these differences are modest in comparison with the variation obser ved for higher-risk cancer surgeries.