Local excision and adjuvant chemoradiation vs radical surgery for early-stage low-risk rectal cancer

Total mesorectal excision for early-stage rectal adenocarcinoma provides maximal oncologic control but is associated with impaired quality of life. Local excision with adjuvant chemoradiotherapy may be an acceptable alternative approach while minimizing morbidity. This study compared overall survival of patients with low-risk pT2N0/x rectal adenocarcinoma treated with total mesorectal excision and those treated with local excision and adjuvant chemoradiotherapy. We hypothesized that there would not be a statistically significant difference in overall survival between these 2 groups.

The National Cancer Database (2004-2020) was queried for patients with cT1N0 and cT2N0 rectal adenocarcinoma who underwent surgery and had pT2N0 or pT2Nx tumors. Patients with tumors that lacked high-risk features were included in a low-risk cohort. Patients were classified by treatment: total mesorectal excision, local excision with adjuvant chemoradiotherapy, or local excision only. The primary outcome of overall survival was compared using Kaplan-Meier survival analysis and Cox proportional hazards regression.

In this study, 8484 patients were included. A total of 6815 (80.3%) underwent total mesorectal excision, 685 (8.1%) underwent local excision with adjuvant chemoradiotherapy, and 984 (11.6%) underwent local excision alone. Median follow-up was 62.1 months. Among patients with low-risk cancer (47.4%), overall survival was similar between those who underwent total mesorectal excision and those who underwent local excision with adjuvant chemoradiotherapy (hazard ratio, 1.25; 95% CI, 0.91-1.72).

In patients with low-risk pT2N0/x rectal adenocarcinoma, a statistically significant difference in overall survival was not observed between treatment with total mesorectal excision and local excision with adjuvant chemoradiotherapy. This finding supports conducting prospective trials to further evaluate this research question.