Upfront surgery versus preoperative chemoradiotherapy: a comparative survival analysis for stage II/III resectable rectal cancer.

Abstract

Purpose: Current international guidelines recommend neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME) for locally advanced rectal cancer (LARC). Although nCRT reduces the risk of local recurrence, it has not demonstrated a survival advantage and increases the likelihood of preoperative overtreatment. This study investigated whether upfront TME could be offered without compromising oncologic outcomes.

Methods: From January 2015 to December 2020, patients with stage II/III LARC who underwent either upfront TME or nCRT followed by TME were analyzed using propensity score matching. Long-term survival outcomes were compared between the 2 groups. The primary endpoint was 5-year disease-free survival. Secondary endpoints included 5-year local recurrence-free survival, distant metastasis-free survival, and overall survival.

Results: A total of 348 patients were included, of whom 138 (39.7%) underwent upfront TME. The upfront TME group showed significantly higher 5-year disease-free survival (63.3% vs. 43.9%) and distant metastasis-free survival (88.1% vs. 70.3%). However, after excluding patients with preoperative mesorectal fascia (MRF) involvement, no significant differences were observed in long-term oncologic outcomes. Following 1:1 propensity score matching, 47 patients from each group were compared. Kaplan-Meier survival analysis revealed no significant differences in any endpoints. Cox regression analysis of the matched cohort indicated that preoperative MRF involvement, positive extramural vascular invasion, and tumor deposits were not independent prognostic factors.

Conclusion: Upfront TME may represent a viable treatment option for selected patients with LARC, particularly those without MRF involvement, providing comparable oncologic outcomes to the standard nCRT approach.