ESTRO 2025 - Abstract Book

S1182

Clinical – Lower GI

ESTRO 2025

planned 7-9 weeks after CRT and the type of surgical approach was left to the surgeon’s discretion. Long-term survival outcomes and toxicity rates according to CTCAEv5.0 were assessed. Overall survival (OS) and disease-free survival (DFS) were calculated in months from the date of the end of CRT to the first event, including last follow-up or death (OS) and/or relapse (DFS) and were estimated by the Kaplan-Meier method. Results: Between October 2015 and October 2022, 44 patients (mean age 64, range 28-78) underwent intensified TNT. All but one had regional lymph node involvement at diagnosis. Of the 44 patients who started induction chemotherapy, 37 (84.1%) received an intensified scheme. All 44 patients started CRT, of which 11 (25%) patients received only concomitant 5-fluorouracil, due to induction chemotherapy-related peripheral neuropathy. During CRT, moderate gastrointestinal toxicity was the most common acute complication, with tenesmus (n = 12; 27.3%), diarrhea (n = 7; 15.9%) and constipation (n = 5; 11.4%). There was no evidence of severe long-term toxicities. Fecal incontinence was recorded in 8 (18.2%) patients and sensory neuropathy in 4 (9.1%) cases. Conservative surgery was carried out in the vast majority of patients (n = 38; 86.4%). Thirteen patients (29.5%) achieved complete (n = 11) or nearly complete response (n = 2). Overall, 11 patients (25.0%) had relapsed either loco-regionally (n = 2) or at metastatic level (n = 9). After a median follow-up of 44.8 months, the 5-year OS and DFS rates were 70.2% (95%CI 0.49-0.84) and 62.2% (95% CI 0.43-0.76), respectively (Figure 1).

Figure 1. Survival curves

Conclusion: Intensified TNT seems to be a plausible regimen in LARC management, with high rate of complete response, survival outcomes and manageable toxicity, opening a new perspective on the organ preservation strategy. An accurate patient stratification should be prioritized in the near future to develop patient-tailored strategies.

Keywords: TNT, rectal cancer, long-term outcomes