Local excision for T1 rectal tumours: are we getting better?

Abstract

The objective was to assess the effect of three different surgical treatments for T1 rectal tumours, radical resection (RR), open local excision (open LE) and laparoscopic local excision (laparoscopic LE), on overall survival (OS). Adults from the National Cancer Database (2008-2016) with a diagnosis of T1 rectal cancer were stratified by treatment type (LE vs RR). We assumed that laparoscopic LE equates to transanal minimally invasive surgery (TAMIS) or transanal endoscopic microsurgery. The primary outcome was 5-year OS. Subgroup analyses of the LE group stratified by time period [2008-2010 (before TAMIS) vs 2011-2016 (after TAMIS)] and approach (laparoscopic vs open) were performed. Among 10053 patients, 6623 (65.88%) underwent LE (74.33% laparoscopic LE vs 25.67% open LE) and 3430 (34.12%) RR. The use of LE increased from 52.69% in 2008 to 69.47% in 2016, whereas RR decreased (P<0.001). In unadjusted analysis, there was no significant difference in 5-year OS between the LE and RR groups (P=0.639) and between the two LE time periods (P=0.509), which was consistent with the adjusted analysis (LE vs RR, hazard ratio 1.05, 95% CI 0.92-1.20, P=0.468; 2008-2010 LE vs 2011-2016 LE, hazard ratio 1.09, 95% CI 0.92-1.29, P=0.321). Laparoscopic LE was associated with improved OS in the unadjusted analysis only (P=0.006), compared to the open LE group (hazard ratio 0.94, 95% CI 0.78-1.12, P=0.495). This study supports the use of a LE approach for T1 rectal tumours as a strategy to reduce surgical morbidity without compromising survival.