ESTRO 2025 - Abstract Book

S1222

Clinical – Lower GI

ESTRO 2025

Keywords: Inflammatory biomarkers, treatment response, LIPI

3023

Proffered Paper Heterogeneity of TNT in rectal cancer - A post-hoc analysis on individual quality of life in disease-free patients in the CAO/ARO/AIO-12 trial Markus Diefenhardt 1,2 , Maximilian Fleischmann 1,3 , Daniel Martin 1,2,3 , Claus Rödel 1,2,3 , Emmanouil Fokas 1,2,4 1 Department of Radiotherapy, University Hospital, Goethe University Frankfurt, Frankfurt, Germany. 2 Frankfurt Cancer Institute, University Hospital, Goethe University Frankfurt, Frankfurt, Germany. 3 Partnersite Frankfurt, German Cancer Research Center (DKFZ) and German Cancer Consortium (DKTK), Frankfurt, Germany. 4 Department of Radiation Oncology, Cyberknife and Radiation Therapy, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologone, Germany Purpose/Objective: Although total neoadjuvant treatment (TNT) results in high rates of tumor regression and potential organ preservation, the potential long-term impact of TNT on individual health-related quality of life (QoL) in rectal cancer patients who remain disease-free is less well understood. Material/Methods: Clinical data from 306 rectal cancer patients treated in the phase II CAO/ARO/AIO-12 trial 1,2 were available to analyze the effects of TNT on health-related quality of life, as assessed by the EORTC QLQ-C30 and EORTC QLQ CR29 questionnaires. We analyzed patients' individual QoL at baseline and how it changed at the individual patient level at least 24 months after randomization in a sub cohort of patients without a DFS event. Exploratory analyses were performed using binary regression models, t-tests and Spearman correlation analyses. Results: Of the 306 eligible patients, 188 remained free from DFS events and QoL data after at least 24 months were available for 139 patients. At randomization, functional scores showed limited disease-related impairment, particularly in emotional functioning. In addition, the functional scores were significantly associated with each other and this correlation persisted during follow-up. In an exploratory regression model adjusted for sex, age and ECOG, baseline QoL status was not significantly correlated with the rate of pCR. At 24 months, overall health status improved in 45% of patients and worsened in 31%. Baseline ECOG 1 was associated with greater deterioration in most (27 of 35) functional scores and symptoms. The relative differences between women and men were most pronounced for buttock pain, diarrhea, stool frequency and urinary incontinence (worse in women) and for dysuria, weight and embarrassment (worse in men). In addition, older age correlated with an increase in stoma problems, while younger patients were more likely to experience an increase in bloating and urinary frequency. Financial worsening was more common in younger patients than in pensioners (39% vs. 13%). Conclusion: The present findings can help improve the selection of patients for watch-and-wait strategies and to better advise rectal cancer patients about the potential long-term effects of TNT on different health-related quality of life facets. In addition, the exclusion of patients with progressive disease from the analysis of QoL should be critically reconsidered.

Keywords: rectal cancer, TNT, QoL