Principles of Molecular Utility for CMS Classification in Colorectal Cancer Management.

Colorectal cancer (CRC) is the second cause of cancer-related deaths in both sexes globally and presents different clinical outcomes that are described by a range of genomic and epigenomic alterations. Despite the advancements in CRC screening plans and treatment strategies, the prognosis of CRC is dismal. In the last two decades, molecular biomarkers predictive of prognosis have been identified in CRC, although biomarkers predictive of treatment response are only available for specific biological drugs used in stage IV CRC. Translational clinical trials mainly based on "omic" strategies allowed a better understanding of the biological heterogeneity of CRCs. These studies were able to classify CRCs into subtypes mainly related to prognosis, recurrence risk, and, to some extent, also to treatment response. Accordingly, the comprehensive molecular characterizations of CRCs, including The Cancer Genome Atlas (TCGA) and consensus molecular subtype (CMS) classifications, were presented to improve the comprehension of the genomic and epigenomic landscapes of CRCs for a better patient management. The CMS classification obtained by the CRC subtyping consortium categorizes CRC into four consensus molecular subtypes (CMS1-4) characterized by different prognoses. In this review, we discussed the CMS classification in different settings with a focus on its relationships with precursor lesions, tumor immunophenotype, and gut microbiota, as well as on its role in predicting prognosis and/or response to pharmacological treatments, as a crucial step towards precision medicine.

Plasma miR-183-5p in colorectal cancer patients as potential predictive lymph node metastasis marker.

Background: Lymph node metastasis (LNM) is a point that often, treatment is not effective in colorectal cancer (CRC). Clinical and pathologic markers of prognosis help clinicians in selecting patients for adjuvant therapy after surgical resection in CRC. MiR-183-5p has been demonstrated to play as an oncogene in CRC, although its biological role still remains unclear. The aim of this study was to evaluate the expression of miR-183-5p in CRC and its potential relevance to clinicopathological characteristics as a prognostic biomarker. Materials and Methods: In this case-control study, 33 CRC plasma samples at stage I-II-III, as well as plasma samples from 13 healthy controls, were collected. The relative expression levels of miR-183-5p in cancer and the normal samples were measured by quantitative real-time PCR. We analyzed their correlation with clinicopathological parameters and prognostic value. Results: Our results indicated that miR-183-5p was significantly overexpressed in CRC samples compared to healthy controls (P < 0.001) from a cutoff value of 3.9 with a sensitivity of 89% and a specificity of 91% and an AUC value of 0.74. Further analysis showed that a high plasma expression level of miR-183-5p was significantly associated with LNM and higher tumor/node/metastases stage (III) (P-value < 0.001).In conclusion, the overexpression of miR-183-5p is highly related to advanced clinical stage, LNM and poor prognosis of CRC, indicating that miR-183-5p may serve as a predictive biomarker for the prognosis or the aggressiveness of CRC.