Preoperative Risk Analysis for Postoperative Recurrence in Locally Advanced Rectal Cancer Following Chemoradiotherapy

Abstract

Background/aim: In patients with locally advanced rectal cancer (LARC), identifying cases in which chemoradiotherapy (CRT) alone is insufficient for disease control may help define the optimal indications for total neoadjuvant therapy (TNT), particularly before its widespread adoption. This is especially relevant in regions where TNT has not yet become the standard of care. The aim of this study was to identify preoperative risk factors for postoperative recurrence in patients with LARC who underwent CRT followed by total mesorectal excision (TME).

Patients and methods: This single-center, retrospective cohort study used prospectively collected clinical data. Patients aged ≥18 years who underwent preoperative CRT, followed by TME for clinical stage II-III primary, middle-to-low rectal adenocarcinoma between January 2018 and March 2024, were included.

Results: During the 75-month study period, 121 patients met the inclusion criteria, and 33% of postoperative recurrences were confirmed during the observation period, including 14% local, 28% distant, and 9% both local and distant recurrences. Multivariate analysis revealed that tumor size ≥50 mm and extramural venous invasion (EMVI) score 4 were independent preoperative risk factors for postoperative recurrence. Relapse-free survival (RFS) was significantly shorter in the high-risk group, with a tumor size ≥50 mm and an EMVI score of 4.

Conclusion: RFS was significantly shorter in the high-risk group, with a tumor size ≥50 mm and an EMVI score of 4. The site of postoperative recurrence in the high-risk group was distant in all cases. In this group, CRT alone may be insufficient as neoadjuvant therapy to control distant recurrence.

Keywords: Chemoradiotherapy; extramural venous invasion; magnetic resonance imaging; neoadjuvant therapy; rectal neoplasm.