ESTRO 2021 Abstract Book

S199

ESTRO 2021

OC-0293 TNT in rectal cancer: Final results of the CAO/ARO/AIO-12 randomized phase 2 trial E. Fokas 1 , A. Schlenska-Lange 2 , B. Polat 3 , G. Klautke 4 , R. Fietkau 5 , T. Kuhnt 6 , T. Brunner 7 , A. Grosu 8 , S. Kirste 8 , M. Flentje 9 , C. Germer 10 , W. Bechstein 11 , T. Friede 12 , R. Hofheinz 13 , M. Ghadimi 14 , C. Rödel 15 1 University of Frankfurt, Department of Radiotherapy and Oncology, Frankfurt, Germany; 2 Barmherzige Brüder Hospital Regensburg, Department of Haematology and Oncology, Regensburg, Germany; 3 University of Würzburg, Department of Radiation Oncology, Würzburg, Germany; 4 DiaCura & Klinikum Coburg, Department of Radiation Oncology and Radiotherapy, Coburg, Germany; 5 University of Erlangen-Nürnberg, Department of Radiation Therapy, Erlangen, Germany; 6 University of Leipzig, Department of Radiation Therapy, Leipzig, Germany; 7 University of Magdeburg, Department of Radiation Therapy, Magdeburg, Germany; 8 Medical Center University of Freiburg, Faculty of Medicine, Freiburg, Department of Radiation Oncology, Freiburg, Germany; 9 University of Würzburg, Department of Radiation Oncology, Würzburg, Germany; 10 University of Würzburg, Department of General and Visceral Surgery, Würzburg, Germany; 11 University of Frankfurt, Department of General and Visceral Surgery, Frankfurt, Germany; 12 University Medical Center Göttingen, Department of Medical Statistics, Göttingen, Germany; 13 University Hospital Mannheim, Department of Medical Oncology, Mannheim, Germany; 14 University Medical Center Göttingen, Department of General and Visceral Surgery, Göttingen, Germany; 15 University of Frankfurt, Department of Radiotherapy and Oncology , Frankfurt, Germany Purpose or Objective In this multicenter, randomized, phase 2 total neoadjuvant therapy (TNT) trial, the sequence chemoradiotherapy (CRT) followed by consolidation chemotherapy (CT) and total mesorectal excision (TME) resulted in a higher pathologic complete response rate (pCR, primary endpoint) than CT followed by CRT in patients with stage II/III rectal cancer. Here, we report long-term results. Materials and Methods Patients were randomly assigned to group A for 3 cycles of fluorouracil, leucovorin, oxaliplatin prior to fluorouracil/oxaliplatin CRT (50.4 Gy), or to group B for CRT prior to CT. Secondary endpoints included oncological outcomes, chronic toxicity, patient reported outcome measures (PROM) for global health status (GHS)/quality of life (QoL), and Wexner stool incontinence score. Results