Influence of the level of sacrectomy on survival in patients with locally advanced and recurrent rectal cancer

Background: Exenterative surgery for locally advanced rectal cancer may involve partial sacrectomy to achieve complete resection. High sacrectomy is technically challenging, and can be associated with high morbidity and mortality rates. The aim of this study was to determine the influence of the level of sacrectomy on the survival of patients with locally advanced rectal cancer. Methods: This was an international multicentre retrospective analysis of patients undergoing exenterative abdominosacrectomy between July 2006 and June 2016. High sacrectomy was defined as resection at or above the junction of S2-S3; low sacrectomy was below the S2-S3 junction. Kaplan-Meier survival analysis was used to assess overall survival and cancer-specific survival. Predictive factors were determined using Cox regression analysis. Results: A total of 345 patients were identified, of whom 91 underwent high sacrectomy and 254 low sacrectomy. There was no difference in 5-year overall survival (53 versus 44.1 per cent; P=0.216) or cancer-specific survival (60 versus 56.1 per cent; P=0.526) between high and low sacrectomy. Negative margin rates were similar for primary and recurrent disease: 65 of 90 (72 per cent) versus 97 of 153 (63.4 per cent) (P=0.143). Level of sacrectomy was not a significant predictor of mortality (P=0.053). Positive resection margin and advancing age were the only significant predictors for death, with hazard ratios of 2.78 (P < 0.001) and 1.02 (P = 0.020) respectively. Conclusion: There was no survival difference between patients who underwent high or low sacrectomy. In appropriately selected patients, high sacrectomy is feasible and safe.