Possibility of Polymicrobial Synergy and Dysbiosis of Periodonto Pathogens in the Oral Squamous Cell Carcinoma Tumour Microenvironment

At least 15% of oral cancer is suspected to be associated with chronic inflammation. Hence, the role of infection associated inflammation in oral cancer gained much attention [1-3]. Recent past epidemiological evidence, facilitated the emergence of poor oral hygiene as an independent risk factor for oral squamous cell carcinoma (OSCC) [4-6]. Periodontitis is the most devastating outcome of poor oral hygiene [7]. In several epidemiological studies, periodontitis reported to be associated with increased risk of OSCC [8-12]. Periodontitis is an inflammatory disease of the periodontium with polymicrobial aetiology [13]. Interestingly, carcinogenic attributes of two periodontopathogenic bacteria Fusobacterium nucleatum [3] and Porphyromonas gingivalis [3] have been investigated by number of in vivo and in vitro experiments. Promising evidence has been obtained, thus inhibition of apoptosis, activation of uncontrolled cell proliferation, promotion of cell migration/ invasion as well production of carcinogenic virulence factors reported to be responsible for oral carcinogenesis [3]. Evidently, these two periodonto pathogens have been associated with oral, pancreatic and colorectal (CRC) cancers by facilitating chronic inflammation and suppressing immuno surveillance [3].