Work

Complete pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer and systemic oncologic benefit: a retrospective cohort study in Korea

Year: 2026

Type: article

Abstract: PURPOSE: Neoadjuvant chemoradiotherapy (CRT) improves local control in locally advanced rectal cancer (LARC) but has not consistently demonstrated a survival benefit. This study evaluated whether pathological complete response (ypCR) after CRT confers systemic oncological benefit beyond local tumor control. METHODS: A total of 1,105 patients with clinically staged T3 or node-positive rectal cancer who underwent total mesorectal excision at a single tertiary center between 2004 and 2019 were categorized into 3 groups: no CRT (n=608), non-ypCR (n=414), and ypCR (n=83). Primary outcomes were 5-year overall survival (OS) and relapse-free survival (RFS). Secondary outcomes were 5-year cumulative incidences of local recurrence and distant metastasis. RESULTS: Five-year OS rates were 77.6%, 82.0%, and 95.7% in the no-CRT, non-ypCR, and ypCR groups, respectively. The ypCR group demonstrated superior OS compared with both no-CRT and non-ypCR groups (P=0.001 and P=0.007, respectively). The marginal OS difference between the no-CRT and non-ypCR groups (P=0.047) was no longer significant after multivariable adjustment (hazard ratio, 0.903; P=0.622). Five-year RFS rates were 69.6%, 72.5%, and 91.1% in the no-CRT, non-ypCR, and ypCR groups, respectively. The 5-year cumulative incidence of distant metastasis was lower in the ypCR group (7.5%) than in the no-CRT and non-ypCR groups (23.8% and 25.0%, respectively; P=0.005). On multivariable analysis, ypCR remained independently associated with reduced risks of death, relapse, and distant metastasis. CONCLUSION: The ypCR after neoadjuvant CRT in LARC was associated with superior survival and reduced distant metastasis, suggesting effective systemic tumor control rather than a local treatment effect alone.

Source: Annals of Coloproctology

DOI: 10.3393/ac.2026.00549.0078