National Early Rectal Cancer Treatment Revisited.

Abstract

Treatment of early stage rectal cancer has excellent oncological results. To reduce treatment-related mortality and morbidity and improve functional results, a focus on local resections is increasingly important. The purpose of this study was to compare outcomes after transanal endoscopic microsurgery and total mesorectal excision for early stage rectal cancer (T1 + T2) in Norway. This was an observational study based on prospective data from the Norwegian Colorectal Cancer Registry. The study was conducted as a national, population-based study. All 543 patients with T1 and 1593 patients with T2 rectal cancer without distant metastases that was treated by transanal endoscopic microsurgery or total mesorectal excision without radiochemotherapy during 2000-2009 were included. The primary outcomes were 5-year relative survival and 5-year local recurrence rate. Among 543 patients with T1 cancer, the 5-year overall survival rate was 65.3% after transanal endoscopic microsurgery versus 81.5% after total mesorectal excision (p = 0.012). Adjusted for age and sex there was no excess mortality for transanal endoscopic microsurgery (HR = 1.28 (95% CI, 0.8-1.9); p = 0.22). The 5-year relative survival rate was 96.8% after transanal endoscopic microsurgery versus 98.2% after total mesorectal excision (p = 0.603), and the 5-year local recurrence rate was 14.5% versus 1.4% (p < 0.001). Among 1593 patients with T2 cancer, 5-year overall survival was 42.1% versus 76.1% (p < 0.001), 5-year relative survival was 65.4% versus 93.9% (p < 0.001), and 5 year local recurrence rate was 11.4% versus 4.4% in the 2 groups. The study is limited by its observational design and that the 2 groups were different according to patient and tumor characteristics. Another limitation was the low number of transanal endoscopic microsurgery procedures. Transanal endoscopic microsurgery had comparable 5-year relative survival to total mesorectal excision in T1 rectal cancer but inferior 5-year relative survival in T2 rectal cancer. Transanal endoscopic microsurgery was associated with higher local recurrence rates for both T1 and T2 tumors.