Tumour grade regression (trg) and correlation with magnetic resonance imaging (mri) in rectal cancer

Purpose: Colorectal cancer is the third most common cancer worldwide, neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer (LARC) and Magnetic Resonance Imaging (MRI) plays an important role in the management of this cases, determining the response to treatment but nowadays does not exist an unique criteria to unify tumour regression grade (TRG) and determinate possible patients for watch and wait and surgical option. 137 patients: 71 (51,8%) m Method: en and 66 (48,2%) women with newly diagnosis of LARC underwent to nCRT and evaluate locally with MRI were analyzed to determinate the circumferential resection margin (CRM), extramural vascular invasion (EMVI), satellite tumour deposit (STD), the state of the sphincter complex (SC) and mrTRG evaluated by experienced abdominal radiologist. Complete pathological response (cPR) was determinate in Result: 30 patients, 57,5% presented partial pathological response (pPR), CRM were 26,4%, EMVI were 18,4%, STD were 14,6% and SCI 6,9% all of them with statistical signicative (p<0,05) relationated with overall survival (OS), mrTRG 1-2 were 43,33% and mrTRG 3-5 40%. MRI is a Conclusion: feasible option to determinate TRG in patients with LARC underwent to nCRT and mrTRG criteria are the best option to classify these patients and with new biopsy could be the standard of care for offers watch and wait option to determinate patients, avoiding in many cases surgical option.