Oncological outcomes after a pathological complete response following total neoadjuvant therapy or chemoradiotherapy for high-risk locally advanced rectal cancer in the RAPIDO trial

• DOI: 10.1016/j.ejca.2024.114044
• Publication Date: 2024-04-07T05:40:23Z
• Authors: Wouter H. Zwart; Sofieke J.D. Temmink; Geke A.P. Hospers; Corrie A.M. Marijnen; Hein Putter; Iris D. Nagtegaal; Lennart Blomqvist; Elma Meershoek-Kl...; Annet G.H. Roodvoets; Anna Martling; Cornelis J.H. van...; Bengt Glimelius; Koen C.M.J. Peeters; Boudewijn van Etten; Per J. Nilsson
• Keywords: Neoadjuvant Therapy; Carcinoembryonic antigen; Chemoradiotherapy

Background A pathological complete response (pCR) following chemoradiation (CRT) or short-course radiotherapy (scRT) leads to a favourable prognosis in patients with rectal cancer. Total neo-adjuvant therapy (TNT) doubles the pCR rate, but it is unknown whether oncological outcomes remain and same characteristics are associated as after CRT. Methods Comparison between RAPIDO trial experimental [EXP] (scRT, chemotherapy, surgery, TNT) standard-of-care treatment [STD] (CRT, postoperative chemotherapy depending on hospital policy) groups. Primary secondary were time-to-recurrence (TTR), overall survival (OS) association patient, tumour, pCR. Results Among resection within six months preoperative treatment, 120/423 (28%) 57/398 (14%) achieved Following pCR, 5-year cumulative TTR OS rates EXP STD arms 8% vs. 7% (hazard ratio 1.04, 95%CI 0.32-3.38) 94% 93% 1.41, 0.51-3.92), respectively. Besides (odds 2.70, 1.83-3.97), pre-treatment carcinoembryonic antigen (CEA) <5, tumour size <40 mm cT2 Distance from anal verge was only characteristic statistically significant difference (Pinteraction=0.042). did not increase prolonged time. Conclusions The doubled rate of TNT compared CRT results similar outcomes. Characteristics normal CEA, small size.