S733
Clinical – Lower GI
ESTRO 2026
United Kingdom. 3 Sussex Cancer Centre, Royal Sussex County Hospital, Brighton, United Kingdom. 4 Dept of Medical Physics & Biomedical Engineering, University College London, London, United Kingdom. 5 Department of Oncology, Oxford University Hospitals NHS Trust, Oxford, United Kingdom. 6 Division of Cancer Sciences, School of Medical Sciences, Faculty of
Results: Between February 2017 and August 2023, 709 patients were recruited from 36 UK sites with 3 ACT4 patients excluded from the modified intention to treat population. 698/706 (98.9%) consented to PRO completion, and 86.0% completed PROs at 6-months. ACT3 observation arm serves as calibration. At baseline, ACT5 patients reported markedly worse scores (>10 points) than ACT3 and ACT4 for role, social and bowel function, fatigue, anorectal pain, planning activities, and cleaning yourself more often. Across all arms, large declines (>20 points) in these domains occurred at end of treatment, with recovery to baseline by 6-months for most issues. However, ACT5 patients continued to report >10-point worse mean scores at 6-months compared to ACT3 and ACT4. Sexual function in ACT4 standard arm and ACT5 remained >10 points worse than baseline for males and females at 6-months, while ACT4 reduced-dose arm returned to baseline. ACT3 sample was too small for meaningful interpretation of sexual function scores. Conclusion: PLATO demonstrates the feasibility of risk-adapted radiotherapy within a multi-arm platform, achieving excellent PRO compliance. While quality of life declined significantly during treatment, most domains recovered by 6-months. These findings highlight the sensitivity of the EORTC QLQ-ANL27 in detecting both acute treatment effects and persistent disease-related impairments, particularly in patients receiving dose- escalated therapy (ACT5). Incorporating validated, disease-specific PRO measures such as QLQ-ANL27 is essential for guiding future treatment optimisation. Longer-term follow-up to 36-months will provide critical insights into the late impact of risk-adapted
Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom. 7 Manchester Cancer Research Centre, NIHR
Manchester Biomedical Research Centre, Manchester, United Kingdom. 8 National Radiotherapy Trials QA (RTTQA) Group, RTTQA, Cardiff, United Kingdom. 9 Medical Physics, St. Bartholomew’s Hospital, London, United Kingdom. 10 Patient Advocate, n/a, London, United Kingdom. 11 Mount Vernon Centre for Cancer Treatment, Mount Vernon Hospital, Northwood, United Kingdom. 12 School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom. 13 Institute of Cancer Research and the Royal Marsden, Royal Marsden, London, United Kingdom. 14 Centre for Trials Research, Cardiff University, Cardiff, United Kingdom. 15 Leeds Cancer Centre, St. James’s University Hospital, Leeds, United Kingdom. 16 Bristol Haematology and Oncology Centre, University Hospitals Bristol, Bristol, United Kingdom. 17 Department of Oncology, Royal Surrey Hospital, Guildford, United Kingdom. 18 Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom Purpose/Objective: The Personalising Radiotherapy Dose in Anal Cancer (PLATO) platform was designed to evaluate risk- adapted optimisation of radiotherapy dose for anal squamous cell carcinoma (ASCC). A key secondary endpoint was the impact of risk-adapted treatment on patient-reported outcomes (PROs), using the EORTC QLQ-ANL27—the first validated, disease-specific PRO measure for anal cancer(1). Material/Methods: The PLATO platform comprises three trials:ACT3: Non- randomised, assessing adjuvant low dose chemoradiotherapy for locally excised T1N0/x anal margin ASCC (41.3 Gy/23 fractions involved field vs observation).ACT4: Randomised, reduced-dose chemoradiotherapy for early T1/2N0/x (<4 cm) ASCC (41.3 Gy/23 fractions vs 50.4 Gy/28 fractions).ACT5: Randomised, dose-escalated chemoradiotherapy for locally advanced T3/4 or N+ ASCC (53.2 Gy, 58.8 Gy, or 61.6 Gy/28 fractions).Validated PROs (EORTC QLQ-C30 and ANL27) were collected at baseline, end of treatment, and 6-weeks, 6-, 12-, 24-, and 36-months post-treatment. Descriptive analysis was performed up to 6-months; mean changes >10 points were considered clinically relevant(2, 3)(26).
radiotherapy. References:
1. Sodergren SC, Johnson CD, Gilbert A, Darlington A-S, Cocks K, Guren MG, et al. International validation of the EORTC QLQ-ANL27, a field study to test the anal cancer-specific health-related quality of life questionnaire. International Journal of Radiation Oncology*Biology*Physics. 2022.2. Fayers P, Aaronson NK, Bjordal K, Groenvold M, Curran D, Bottomley A. EORTC QLQ-C30 scoring manual. Brussels, Belgium: European Organisation for Research and Treatment of Cancer; 1999.3. Osoba D, Rodrigues G, Myles J, Zee B, Pater J. Interpreting the significance of changes in health-related quality-of-life scores. J Clin Oncol. 1998;16(1):139-44. Keywords: anal cancer, quality of life
Made with FlippingBook - Share PDF online