Multivariate analyses to assess the effect of surgeon volume on survival rate in oral cancer: a nationwide population-based study in Taiwan.

Patients with oral cancer utilize considerable health care resources, particularly when wide resection of the tumor and reconstruction with pedicle flap/free flap is performed. This study was conducted to explore the relationship between survival rates and surgeon volume. A total of 1256 patients who underwent resections for oral cancer in 2005 were identified from the Taiwan National Health Insurance Research Database. Survival analysis, the Cox proportional regression model, and propensity score were used to evaluate the association between 3-year survival rates and surgeon caseloads. Oral cancer patients treated by high-volume surgeons (caseload 22-117) had better survival rates (hazard ratio [HR]=0.656; 95% confidence interval [CI], 0.484-0.89; P=0.007) using the Cox proportional regression model after adjusting for patients' comorbid conditions, hospital, and surgeon characteristics. When analyzed by propensity score, the adjusted 3-year survival rate was 74% for patients treated by high-volume surgeons compared to 58% in the low/medium-volume group (P=0.019). We concluded that for patients who underwent oral cancer resection and reconstruction, after adjusting for differences in the case mix, high-volume surgeons had better 3-year survival rates. Treatment strategies adopted by high-volume surgeons should be analyzed further and utilized more widely.