Personalized medicine in patients with colorectal cancer

Colorectal cancer (CRC) is the third and fourth most common cause of cancer and cancer death worldwide, respectively. One of the therapeutic approaches is to target Human epidermal growth factor receptor 2 (HER2) using Trastuzumab (Herceptin™), a monoclonal antibody that acts by blocking the HER2 receptor.HER2 is a well-established and effective therapeutic target in breast and gastric cancers. Importantly, HER2 was found to be overexpressed in some proportion of CRC cells, and seems to be a potentially valid target of interest in the management of colorectal tumors. However, unlike breast and stomach cancers, membranous overexpression of HER2 is usually found in a very low percentage (only 5%) of patients with CRC. In addition, the frequency of HER2 has been found to vary in colorectal tumors. This is the reason why a considerable number of patients do not respond or lose response to this therapy. The infrequency of HER2 overexpression in the membrane of CRC cells, which is required for trastuzumab therapy, is one of the main obstacles that hinder the therapeutic application of trastuzumab in CRC patients. There is a need for new therapy modalities to improve the survival time for patients with CRC. Personalized medicine using targeted therapy is one of the most significant and successful modalities in the development of novel treatment for patients with CRC. Identification of a subset of CRC patients with HER2 abnormalities represents an opportunity for precision oncology.The classification of CRC to various subtypes, as well as further subgrouping of HER2+ cancer based on the expression profiles of critical molecules such as other HER family receptors, makes it possible for the development of personalized medicine in treating CRC patients. Personalized medicine based on the molecular profile of each individual is the future of CRC management.

Keywords:

Colorectal Cancer , HER2 , Trastuzumab , Targeted therapy