Non-operative management in low-lying rectal cancers undergoing chemoradiation.

Purpose: To evaluate the outcomes of post-neoadjuvant chemoradiation (NACTRT) wait-and-watch Strategy (WWS) in distal rectal cancers.

Materials And Methods: All consecutive patients from December 2012 to 2019 diagnosed with distal rectal tumors (T2-T4 N0-N+) having a complete or near-complete response (cCR or nCR, respectively) post-NACTRT and wishing for the non-surgical treatment option of WWS were included in this study. Patients were observed with 3 monthly magnetic resonance imaging (MRIs), sigmoidoscopies, and digital rectal examination for 2 years and 6 monthly thereafter. Organ preservation rate (OPR), local regrowth rate (LRR), non-regrowth recurrence-free survival (NR-RFS) and overall survival (OAS) were estimated using the Kaplan-Meier method, and factors associated with LRR were identified on univariate and multivariate analysis using the log-rank test (P < 0.05 significant).

Results: Sixty-one consecutive patients post-NACTRT achieving cCR[44 (72%)] and nCR[17 (28%)], respectively, were identified. All patients received pelvic radiotherapy at a dose of 45-50Gy conventional fractionation and concurrent capecitabine. An additional boost dose with either an external beam or brachytherapy was given to 39 patients. At a median follow-up of 39 months, 11 (18%) patients had local regrowth, of which seven were salvaged with surgery and the rest are alive with the disease, as they refused surgery. The overall OPR, NR-RFS, and OS were 83%, 95%, and 98%, respectively. Seven (11%) patients developed distant metastasis, of which six underwent metastatectomy and are alive and well. LRR was higher in patients with nCR versus cCR (P = 0.05).

Conclusion: The WWS is a safe non-operative alternative management for selected patients attaining cCR/nCR after NACTRT with excellent outcomes.