Local excision of a residual tumor after neoadjuvant chemoradiotherapy for rectal cancer (a systematic review and meta-analysis of comparative studies)

Vollständiger Abstract

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B ACKGROUND: the optimal treatment strategy for patients with rectal cancer who achieve a complete or nearcomplete clinical response after neoadjuvant chemoradiotherapy is challenging. AIM: to assess oncological outcomes after neoadjuvant chemoradiotherapy followed by total mesorectumectomy (TME) or local excision of residual rectal tumor (TEM). MA TERIALS AND METHODS: a systematic review and meta-analysis were done according to the PRISMA 2020 guidelines. A literature search included PubMed, MEDLINE, and e-library databases until April 2025. Inclusion criteria were studies comparing long-term outcomes in patients treated with neoadjuvant chemoradiotherapy followed by surgical treatment consisting of total mesorectumectomy or local excision of residual rectal tumor. Exclusion criteria were lack of information on the study endpoints, unbalanced group sizes, preliminary results and a high risk of bias in quality of full-text articles. The primary endpoints of the study were 5-year disease-free survival (DFS) and overall survival (OS). Secondary endpoints included 1and 3-year DFS, 3-year OS, local recurrence rate and distant metastases. Generalized Kaplan-Meier curves were constructed for the meta-analysis of DFS and OS. RESULT S: the study included 10 comparative studies (3 randomized, 1 prospective, and 6 retrospective). The incidence of local recurrence was significantly higher in the TEM group than in TME — 36/496 (7.3%) versus 22/577 (3.8%) (OR = 1.85; 95% CI: 1.05–3.25; p = 0.032). The groups were comparable in distant metastases rate — 35/420 (8.3%) cases in the TEM group and 52/498 (10.4%) in TME (OR = 0.79; 95% CI: 0.49–1.27; p = 0.326). The median follow-up was 52.5 (95% CI: 49.4–52.5) months for the TEM group and 55.2 (95% CI: 55.2–59.7) months for TME. No significant differences in DFS were found between groups (p, log-rank test = 0.39). Five-year DFS was 79.2% (95% CI: 74.8–83.9) for TEM and 80.9% (95% CI: 76.9–85.1) for TME. When analyzing the hazard ratio, no advantage of TME over TEM was proven in DFS (HR = 1.31; 95% CI: 0.93–1.85; p = 0.117). In terms of overall survival, both treatment methods were comparable (p, log-rank test = 0.43), and the 5-year OS was 88.9% (95% CI: 85.4–92.6) for TEM and 87.6% (95% CI: 84.1–91.2) for TME. Hazard ratio analysis revealed no statistically significant differences (HR = 1.11; 95% CI: 0.70–1.71; p = 0.656). CONCLUSION: TEM is comparable to TME in oncological outcomes of patients with complete or near-complete clinical response after neoadjuvant chemoradiotherapy. However, selection criteria for this group of patients should be taken into account, such as the presence of a near-complete clinical response, small residual tumor size, affected mesorectal lymph nodes, and a tumor regression grade mrTRG 0-1.