ESTRO 2024 - Abstract Book

S1481

Clinical - Lower GI

ESTRO 2024

4. Hanna GG, Hounsell AR, O’sullivan JM. Geometrical Analysis of Radiotherapy Target Volume Delineation: a Systematic Review of Reported Comparison Methods Statement of Search Strategies Used and Sources of Information. Clin Oncol. 2010;22.

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Mini-Oral

Assessing the benefit of adjuvant chemotherapy for rectal cancer: a real-world analysis

Catherine R Hanna 1 , Hans W de Wilt 2 , Amy Downing 3 , Tijmen Koeter 4 , Harm JT Rutten 5 , Felice van Erning 6 , Henk MW Verheul 7 , Eva Morris 8 , Rebecca Muirhead 9 1 University of Glasgow, CRUK Glasgow Clinical Trials Unit, Institute of Cancer Sciences, Glasgow, United Kingdom. 2 Radboud University Medical Center, Department of Surgery, Nijmegen, Netherlands. 3 University of Leeds, Leeds Institute of Medical Research at St James's and Leeds Institute for Data Analytics, Leeds, United Kingdom. 4 Elisabeth-TweeSteden Hospital, Department of Surgery, Tilburg, Netherlands. 5 Catharina Hospital, Department of Surgery, Eindhoven, Netherlands. 6 Netherlands Comprehensive Cancer Organisation, Department of Research and Development, Utrecht, Netherlands. 7 University Medical Center, Department of Medical Oncology, Rotterdam, Netherlands. 8 University of Oxford, Nuffield Department of Population Health, Big Data Institute, Oxford, United Kingdom. 9 Oxford University Hospitals NHS Foundation Trust, Department of Oncology, Oxford, United Kingdom

Purpose/Objective:

There is no consensus for the use of adjuvant chemotherapy after radical resection in rectal cancer. As such, international practise varies widely. The UK extrapolate from colon trials, offering adjuvant chemotherapy widely amongst Stage II/III patients, while in the Netherlands, its use is not recommended in national guidelines. While the main objective of the recent RAPIDO [1] and PRODIGE-23 [2] trials was to assess the benefit of intensifying neoadjuvant treatment, they both included adjuvant chemotherapy as part of treatment protocols both in experimental and control arms. As such, it is challenging to interpret and apply results without quantifying the benefit of adjuvant chemotherapy. In this study we use real-world data from England and the Netherlands to explore the potential benefit of adjuvant chemotherapy.

Material/Methods:

Routinely collected administrative healthcare data from England (2014-2019) and the Netherlands (NK) (2012 2017) was used to identify patients diagnosed with a clinical or pathological T3, T4, or N+ rectal cancer who were managed with TME resection +/- neoadjuvant (chemo)radiotherapy). All those with metastatic disease or who received neo-adjuvant chemotherapy were excluded. Survival times for patients who received adjuvant chemotherapy versus those who did not receive this treatment were compared using the Kaplan-Meier method and log-rank test. The potential influence of treatment related factors on survival in both groups was explored.

Results: