Impact of surgeon volume on outcomes of rectal cancer surgery: a systematic review and meta-analysis.

AIM: To clarify the relationship between surgeon caseload and patient outcomes for patients undergoing rectal cancer surgery in order to inform debate about organisation of services. METHODS: We searched Medline and Embase for articles published up to March 2010, and included studies examining surgeon caseload and outcomes in rectal cancer patients treated after 1990. Outcomes considered were 30-day mortality, overall survival, anastomotic leak, local recurrence, permanent stoma and abdominoperineal excision rates. We assessed the risk of bias in included studies and performed random effects meta-analyses based on both unadjusted and casemix adjusted data. RESULTS: Eleven included studies enrolled 18,301 rectal cancer patients undergoing resective surgery. Unadjusted meta-analysis showed a statistically significant benefit in favour of high volume surgeons for 30-day postoperative mortality (OR = 0.57, 95% CI: 0.43-0.77; based on three studies, 4809 patients) and overall survival (HR = 0.76, 95% CI 0.63-0.90; based on two studies, 1376 patients), although the former relationship was attenuated and non-significant when based on two studies (9685 patients) that adjusted for casemix (OR = 0.79, 95% CI: 0.59-1.06). Pooling of three studies (2202 patients) showed no significant relationship between surgeon volume and anastomotic leak rate. Permanent stoma formation was less likely for high volume surgeons (adjusted OR = 0.75, 95% CI: 0.64 to 0.88; based on two studies, 9685 patients) and APER rates were lower for high volume surgeons (unadjusted OR = 0.58, 95% CI: 0.45 to 0.76); based on six studies, 3921 participants. CONCLUSIONS: This review gives evidence that higher surgeon volume is associated with better overall survival, lower permanent stoma and APER rates.