Caracterización de pacientes con cáncer colorrectal esporádico basado en la nueva subclasificación molecular consenso

Resumen

Background: Colorectal cancer (CRC) is an heterogeneous disease. Three carcinogenic pathways determine its molecular profile: microsatellite instability (MSI), chromosomal instability (CIN) and CpG island methylator phenotype (CIMP). Based on the new molecular classification, four consensus CRC molecular subtypes (CMS) are established, which are related to clinical, pathological and biological characteristics of the tumor. Aim: To classify Chilean patients with sporadic CRC according to the new consensus molecular subtypes of carcinogenic pathways. Material and Methods: Prospective analytical study of 53 patients with a mean age of 70 years (55% males) with CRC, operated at a private clinic, without neoadjuvant treatment. From normal and tumor tissue DNA of each patient, CIN, MSI and CIMP were analyzed. Combining these variables, tumors were classified as CMS1/MSI-immune, CMS2/canonical, CMS3/metabolic and CMS4/mesenchymal. Results: CMS1 tumors (19%) are located in the right colon, are in early stages, have MMR complex deficiencies and 67% have an activating mutation of the BRAF oncogene. CMS2 tumors (31%) are located in the left colon, have moderate differentiation, absence of vascular invasion, lymphatic and mucin. CMS3 tumors (29%) are also left-sided, with absence of vascular and lymphatic invasion, and 29% have an activating mutation of the KRAS oncogene. CMS4 tumors (21%) show advanced stages and presence of metastases. Conclusions: This new molecular classification contributes to understanding the heterogeneity of tumors. It is possible to differentiate molecular subgroups of a single pathological diagnosis of adenocarcinoma, opening the door to personalized medicine.