Salvageable locoregional recurrence and stoma rate after local excision of pT1-2 rectal cancer - A nationwide cross-sectional cohort study

Background: Screening has increased the incidence of early-stage rectal cancer and interest in rectal-preserving treatment strategies. Although guidelines recommend completion total mesorectal excision (cTME) in the presence of histological risk factor(s) after local excision, surgery-related morbidity often deters patients from cTME. Additionally, locoregional recurrences (LR) identified during surveillance may still be salvageable. This study evaluates oncological and surgical outcomes in pT1-2 rectal cancer patients who received local excision with or without additional therapy. Methods: A retrospective cross-sectional national cohort study was conducted in 67 Dutch hospitals, including all patients who underwent curative surgical resection for rectal cancer in 2016. Patients with pT1-2 tumours who received surveillance, cTME or adjuvant chemoradiotherapy after local excision were selected. The primary outcome was LR. Secondary endpoints included ostomy rate, disease-free survival (DFS), and overall survival (OS). Results: Of 3057 patients, 219 underwent local excision, followed by surveillance in 74 % (n = 162), cTME in 23 % (n = 51), and adjuvant (chemo)radiation in 3 % (n = 6). Median follow-up was 46 months (IQR 29-54). Fouryear LR rates were 14 % and 4 % after surveillance and cTME, respectively (p = 0.033). In the surveillance group, 16 of 20 patients (80 %) who developed LR were treated with curative intent. cTME resulted in a substantially higher ostomy rate (43 % vs 4 %, p = 0.001). No significant differences were found in 4-year DFS and OS. Conclusion: Despite a LR rate of 14 % after local excision alone, the majority of these recurrences could be treated with curative intent. Additionally, the risk of stoma was 10-fold lower after surveillance compared to cTME. Trial registration: ClinicalTrials.gov, identifier: NCT05539417, https://www.clinicaltrials.gov/ct2/show/NC T05539417.