Metachronous serrated neoplasia is uncommon after right colectomy in patients with methylator colon cancers with a high degree of microsatellite instability

Serrated Polyps and Serrated Polyposis Syndrome

Colorectal serrated polyps are intermediate lesions in the serrated neoplastic pathway, which account for up to 30% of colorectal cancers. This pathway is biologically distinct from the adenoma-to-carcinoma sequence, with associated cancers exhibiting mutations in the BRAF oncogene, DNA promoter hypermethylation, and microsatellite instability. An evolving understanding of these unique lesions has led to the development of a more accurate classification, improved endoscopic identification, and tailored clinical management guidelines. This article reviews serrated polyps and serrated polyposis syndrome.

BRAF-mutated colorectal cancer: clinical implications for a distinct subset of the disease

SUMMARY 

Colorectal cancer (CRC) is many diseases, with each case defined by the underlying genetic and molecular changes of that particular tumor. The heterogeneity of CRC emphasizes the need to understand this disease within the context of genetic subsets. BRAF mutations mark a subpopulation that arises through the serrated pathway to carcinogenesis. This subset of cancers is associated with unique clinical and histopathologic characteristics. BRAF-mutated CRCs have a worse prognosis compared with their wild-type counterparts, and may not be as responsive to chemotherapy. Target therapies specifically against BRAF and its related signaling pathways are under both scientific and clinical investigation. This article highlights the clinical relevance of the subset of BRAF-mutated CRCs.

The molecular pathogenesis of colorectal cancer and its potential application to colorectal cancer screening

INTRODUCTION

Advances in our understanding of the molecular genetics and epigenetics of colorectal cancer have led to novel insights into the pathogenesis of this common cancer. These advances have revealed that there are molecular subtypes of colon polyps and colon cancer and that these molecular subclasses have unique and discrete clinical and pathological features. Although the molecular characterization of these subgroups of colorectal polyps and cancer is only partially understood at this time, it does appear likely that classifying colon polyps and cancers based on their genomic instability and/or epigenomic instability status will eventually be useful for informing approaches for the prevention and early detection of colon polyps and colorectal cancer.

CONCLUSIONS

In this review, we will discuss our current understanding of the molecular pathogenesis of the polyp to cancer sequence and the potential to use this information to direct screening and prevention programs.