Does oncological outcome differ between restorative and nonrestorative low anterior resection in patients with primary rectal cancer?

Abstract
Aim Nonrestorative low anterior resection (n-rLAR) (also known as low Hartmann's) is performed for rectal cancer when a poor functional outcome is anticipated or there have been problems when constructing the anastomosis. Compared with restorative LAR (rLAR), little oncological outcome data are available for n-rLAR. The aim of this study was to compare oncological outcomes between rLAR and n-rLAR for primary rectal cancer. Method This was a nationwide cross-sectional comparative study including all elective sphincter-saving LAR procedures for nonmetastatic primary rectal cancer performed in 2011 in 71 Dutch hospitals. Oncological outcomes of patients undergoing rLAR and n-rLAR were collected in 2015; the data were evaluated using Kaplan-Meier survival analysis and the results compared using log-rank testing. Uni- and multivariable Cox regression analysis was used to evaluate the association between the type of LAR and oncological outcome measures. Results A total of 1197 patients were analysed, of whom 892 (75%) underwent rLAR and 305 (25%) underwent n-rLAR. The 3-year local recurrence (LR) rate was 3% after rLAR and 8% after n-rLAR (P < 0.001). The 3-year disease-free survival and overall survival rates were 77% (rLAR) vs 62% (n-rLAR) (P < 0.001) and 90% (rLAR) vs 75% (n-rLAR) (P < 0.001), respectively. In multivariable Cox analysis, n-rLAR was independently associated with a higher risk of LR (OR = 2.95) and worse overall survival (OR = 1.72). Conclusion This nationwide study revealed that n-rLAR for rectal cancer was associated with poorer oncological outcome than r-LAR. This is probably a noncausal relationship, and might reflect technical difficulties during low pelvic dissection in a subset of those patients, with oncological implications.