Nonoperative management in low-lying rectal cancers undergoing chemoradiation.

Background: To evaluate outcomes of postneoadjuvant chemoradiotherapy (NACTRT) wait and watch strategy (WWS) in distal rectal cancers.

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 wished for nonsurgical treatment option of WWS were included in this study. Patients were observed with 3 monthly MRI, sigmoidoscopy, and digital rectal examination (DRE) for 2 years and 6 monthly thereafter. Organ preservation rate (OPR), local regrowth rate (LRR), nonregrowth recurrence-free survival, and overall survival (OS) 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 to a dose of 45-50Gy conventional fractionation with concurrent Capecitabine. Additional boost dose with either 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 disease, as they refused surgery. The overall OPR, nonregrowth recurrence-free survival, OS was 83%, 95%, and 98%, respectively. Seven (11%) patients developed distant metastasis, of which six underwent metastasectomy and are alive and well. LRR was higher in patients with nCR versus cCR (P = 0.05).

Conclusion: The wait-and-watch strategy is a safe nonoperative alternative management for selected patients attaining cCR/nCR after NACTRT with excellent outcomes.