Molecular subtyping in colorectal cancer: A bridge to personalized therapy (Review)

Colorectal cancer (CRC) is a malignant tumor and a major cause of morbidity and mortality globally. The classic Tumor-Node-Metastasis staging system, which currently underlies the diagnosis and treatment of CRC, is primarily a 'one drug fits all' model for patients exhibiting the same pathological features. However, a high degree of variability has been established in the long-term survival outcomes of patients with CRC with similar pathological types and stages, which can be partially attributed to tumor-specific molecular biology to some extent. Molecular classification of CRC can further assist with understanding the biological behavior of tumor genesis, development and prognosis, and assist clinicians in improving or customizing the treatment strategy of CRC. In the present study, clinical studies carried out to date are reviewed, and their clinical value is discussed. A multilevel overview of the major molecular types of CRC is provided, in the hope that investigators are encouraged to combine multiple omics studies for interrogating cancer.