FACTORS PREDICT COMPLETE HISTOLOGICAL RESPONSE FOLLOWING NEOADJUVANT RADIOCHEMOTHERAPY FOR RECTAL CANCER

Introduction and Objective:Radiotherapy combined withconcomitant chemotherapy, followed by surgery, is currently the standard treatment for locally advanced rectal cancer. This therapeutic strategy improves local control and increases the sphincter preservation rate. In addition, a pathological complete response (pCR) can be achieved in up to 20% of cas. The objective of our study was to determine the predictive factors for pCR after neoadjuvant RCT. Methods: This is a retrospective study of a series of 430 patients with rectal carcinoma, collected from January 2018 to December 2023 at the National Institute of Oncology in Rabat, who received radiotherapy with concomitant chemotherapy based on Capecitabine and subsequent surgery. Conclusions: Pathological characteristics that have been reported to significantly influence patient outcomes after neoadjuvant RCC include post-treatment pathological stage (ypTNM). They provide a good indicator of tumourradiosensitivity and chemosensitivity. The incidence of complete histological response in our study was 21%. Tumour site, size and differentiation were clinical predictors of a complete histological response associated with a very good prognosis.