Serrated colorectal cancer: Molecular classification, prognosis, and response to chemotherapy

World J Gastroenterol. 2016 Apr 7;22(13):3516-30. doi: 10.3748/wjg.v22.i13.3516.


Molecular advances support the existence of an alternative pathway of colorectal carcinogenesis that is based on the hypermethylation of specific DNA regions that silences tumor suppressor genes. This alternative pathway has been called the serrated pathway due to the serrated appearance of tumors in histological analysis. New classifications for colorectal cancer (CRC) were proposed recently based on genetic profiles that show four types of molecular alterations: BRAF gene mutations, KRAS gene mutations, microsatellite instability, and hypermethylation of CpG islands. This review summarizes what is known about the serrated pathway of CRC, including CRC molecular and clinical features, prognosis, and response to chemotherapy.

Keywords: CIMP; Chemotherapy; Colorectal cancer; Methylator phenotype; Serrated pathway.

Publication types

  • Review

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Biomarkers, Tumor / genetics*
  • Colorectal Neoplasms* / classification
  • Colorectal Neoplasms* / drug therapy
  • Colorectal Neoplasms* / genetics
  • Colorectal Neoplasms* / pathology
  • CpG Islands
  • DNA Methylation
  • Genetic Predisposition to Disease
  • Humans
  • Microsatellite Instability
  • Molecular Diagnostic Techniques*
  • Mutation
  • Neoplasm Staging
  • Phenotype
  • Predictive Value of Tests
  • Proto-Oncogene Proteins B-raf / genetics
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Treatment Outcome


  • Antineoplastic Agents
  • Biomarkers, Tumor
  • KRAS protein, human
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf
  • Proto-Oncogene Proteins p21(ras)