Low-volume centre vs high-volume: the role of a quality assurance programme in colon cancer surgery.

AIM: The study aimed to determine whether hospitals within a quality assurance programme have outcomes of colon cancer surgery related to volume. METHOD: Data were used from an observational study to determine whether outcomes of colon cancer surgery are related to hospital volume. Hospitals were divided into three groups (low, medium and high) based on annual caseload. Cancer staging, resected lymph nodes, perioperative complications and follow up were monitored. Between 2000 and 2004, 345 hospitals entered 31,261 patients into the study: 202 hospitals (group I) were classified as low volume (<30 operations; 7760 patients; 24.8%), 111 (group II) as medium volume (30-60; 14,008 patients; 44.8%) and 32 (groups III) as high volume (>60; 9493 patients; 30.4%). RESULTS: High-volume centres treated more patients in UICC stages 0, I and IV, whereas low-volume centres treated more in stages II and III (P<0.001). There was no significant difference for intra-operative complications and anastomotic leakage. The difference in 30-day mortality between the low and high-volume groups was 0.8% (P=0.023).Local recurrence at 5 years was highest in the medium group. Overall survival was highest in the high-volume group; however, the difference was only significant between the medium and high-volume groups. For the low and high-volume groups, there was no significant difference in the 5-year overall survival rates. CONCLUSION: A definitive statement on outcome differences between low-volume and high-volume centres participating in a quality assurance programme cannot be made because of the heterogeneity of results and levels of significance. Studies on volume-outcome effects should be regarded critically.