Molecular subtypes in early colorectal cancer associated with clinical features and patient prognosis

AbstractPurposeAfter surgical resection, an ample prognosis variability among stages is observed. Multiple prognostic factors are individually studied and some CRC classifiers have been proposed. Not one have been implemented into clinical practice.Methods/patientsWe classified 105 patients with resected CRC (stage I –III) into five molecular subtypes usingBRAFV600E andRAS (KRAS;NRAS) status, and the expression of DNA mismatch repair (MMR) proteins (MLH1 and MSH2). Clinicopathological features and DFS) of distincts groups were evaluated.Results and conclusionsRAS andBRAFV600E mutations were detected in 43.8 and 11.4% of patients, respectively. 19% of tumours had lack of expression of any MMR proteins reflecting a system deficiency (dMMR). Patients with anyRAS mutation had lower DFS that patients withRAS wild type (wt) (40.23 vs 45.26  months;p value  = 0.035). Of a total of five molecular subtypes, three were MMR proficient (pMMR):RAS mutated (39%),BRAFV600E mutated (6.7%) andRAS/BRAFV600E wt (35.2%); and two were dMMR:BRAFV600E mutated (4.8%) andBRAFV600E wt (14.3%). Left side tumours were more frequently observed in pMMR/RAS andBRAFV600E wt subtype, and right side tumours in dMMR subtypes. Among the three pMMR subtypes, a benefit survival was observed for patients without any mutation inBRAFv600E orRAS oncogenes (median of DFS  = 45.5 vs 40.98 months inRAS mutated group;p = 0.084 and vs 34.13 inBRAFv600E mutated group;p = 0.031). Molecular classification...
Source: Clinical and Translational Oncology - Category: Cancer & Oncology Source Type: research