Role of Infectious Agents in Carcinogenesis

There are infectious agents that play a significant role in carcinogenesis in no less than about 15% of cases and such carcinomas are associated with an infection by a specific pathogenic microorganism.A majority of infections that are carcinogenic usually present themselves as potentially modifiable risk factors, and thus, prevention tools already exist for them but are often not implemented.Human microbiome, is a microbiota with a collection of microbial taxa, of trillions of micro-organisms associated with humans and may have an advantageous or deleterious effect on their human host.Oral microbiome is of special significance owing to significantly high alpha diversity, many available niche with specific type of microbiome in each niche and significantly low beta diversity for individuals of a particular habitat.Longterm dysbiosis in any niche, leads to generation of primary & secondary metabolites by pathogenic microbes that, then cause, downstream effects from chronic infection & inflammation with presence of altered virulence factors and disruption of cell cycle and tumor signal transduction regulating cell proliferation and apoptosis as well as altered regulation of host immune response.These complex interactions then, lead to, not only oral carcinogenesis but also carcinomas of other areas of body due to, relatively unrestricted access of oral microbes to other parts of body directly or indirectly.