ESTRO 2025 - Abstract Book

S1237

Clinical – Lower GI

ESTRO 2025

Conclusion: Hypofractionated PT should be considered an effective therapy for PIC. Tumor dimension was found to be associated with LC while an association trend was found between dose (BED >100) and better patients’ outcome.

Keywords: Protontherapy, Hypofractionation, Hepatic cancer

3391

Proffered Paper Vaginal and sexual health after radiotherapy for anal cancer: A national Danish prospective cohort study Johanne H. Steffensen 1,2 , Eva Serup-Hansen 3 , Camilla J.S. Kronborg 4,2 , Karen-Lise G. Spindler 1,5,2 1 Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark. 2 Department of Clinical Medicine, Aarhus University, Aarhus, Denmark. 3 Department of Oncology, Copenhagen University Hospital, Herlev and Gentofte, Denmark. 4 Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark. 5 Department of Oncology, Aarhus University Hospital, Aarhus, Denmark Purpose/Objective: Pelvic radiotherapy (RT) often leads to long-term vaginal and sexual dysfunction 1 , yet prospective data regarding women with anal cancer (AC) remain sparse 2 . To address the scarcity of prospective data on vaginal and sexual health outcomes in women with AC undergoing RT, we aim to evaluate both the prevalence and longitudinal progression of these adverse effects using data from a national Danish cohort. Material/Methods: We conducted a sub-study within the DACG-I prospective cohort (NTC 05570279), including patients treated for AC with curative RT from 2015 to 2020. NCI-CTCAE v4.0 and EORTC Quality of Life Questionnaires C30 and CX24 were used to assess gynecological and sexual toxicities before RT and 1, 3, and 5 years after treatment. We used descriptive analysis to report characteristics before RT and frequencies of CTCAE and PRO responses. The Wilcoxon signed-rank test was used to compare symptom severity across time points. Results: In total, 221 women were enrolled pre-RT; 213, 188, and 131 remained at 1, 3, and 5 years, respectively. Dropout occurred due to death (n=32), withdrawal by patient choice (n=14), and 44 patients who were either not scheduled for or had not yet reached the 5-year follow-up. The mean age at enrollment was 62.2 years. T-site and N+ doses were 60 Gy (25%), 64 Gy (69%), and ≤54 Gy (6%) over 27-32 fractions; elective nodes received 48-51.2 Gy. PRO response rates among the remaining patients were 82.4%-95.5% across time points. Sexual inactivity, reported by 72% before RT, remained stable during follow-up (71% at 5 years). CTCAE ≥ 2: Vaginal dryness increased from 4.8% pre-RT to 9.9% at 1 year (p=0.018), stabilizing at 11.4% at 5 years. Vaginal pain rose from 1.0% to 4.1% at 1 year (p=0.005), remaining stable. The most reported vaginal symptom (EORTC-Cx24) was irritation, increasing from 8.8% pre-RT to 12.7% at 1 year (p=0.008) before plateauing. Among sexually active women, sexual enjoyment dropped from 73.8% pre-RT to 48.7% at 1 year, stabilizing at 53.6% at 5 years. In this group, 42% reported severe vaginal symptoms, rising significantly by 1 year and persisting at 5 years (Table 1).