Mini Review: Gut Microbiome & Early Detection of Colorectal Cancer

Colorectal cancer is the fourth most common diagnosed cancer in Canada, and the third and fourth leading cause of cancer-related deaths in men and women respectively. However, survival is often dependent on the stage of the cancer with stage I having 5-year survival rates as high as 92% while stage IV having a 5-year survival rate of only 11%. Hence, early detection has been key in improving colorectal cancer prognosis. Currently, colonoscopies, fecal immunochemical test (FIT), and guaiac fecal occult blood test (gFOBT) are used in current clinical settings as early detection and screening tools. There has been a growing interest in the gut microbiome, and the role of gut dysbiosis in the development of colorectal cancer. This includes Fusobacterium Nucleatum, Clostridium Symbiosum, and Bacteroides Fragilis. Recent studies have shown that identification of certain changes in the gut microbiota can be used to identify high-risk patients for developing colorectal cancer. Therefore, this mini review focuses on current evidence surrounding the role of gut microbiota and key microorganisms identified in colorectal cancer development. The review also discusses the limitations and gaps in the literature regarding the efficacy of using the gut microbiome as a screening tool for colorectal cancer.