Liaison between micro-organisms and oral cancer

Abstract

Oral cancer which is a subtype of head and neck, cancer is any neoplastic tissue growth in the oral cavity. It comprises an abnormal mass of cells that foists genetic mutation and impedes the normal cell cycle, resulting in its unrestrained growth. Various studies on the plausible link between oral microbial flora and cancer notwithstanding, our understanding of their link remains obscure and inadequate. The multitude of mechanisms by which the microflora initiate or spur Carcinogenesis are still under study and scrutiny. As is widely known, the oral cavity is an abode to a wide assortment of microbes, each present in contrasting amounts. It is observed that increased growth of the microflora is concomitant with known clinical risk factors for oral cancer. Manifold bacterial species have been found to interfere directly with eukaryotic cellular signaling, adopting a style typical of tumor promoters. Bacteria are also known to impede apoptosis thereby potentially promoting carcinogenesis. The viral role in carcinogenesis (by annulling of p53 tumor suppressor gene and other cellular proteins with subsequent alteration in host genome function) is well documented. Furthermore, the changes occurring in the commensal microflora in accompaniment with cancer development could possibly be used as a diagnostic indicator for early cancer detection. The intention of this review is to obtain a better understanding of the "role" that micro-organisms play in oral cancer etiology.

Keywords: Candida albicans; bacteria; human papillomavirus; oral cancer.

Figure 1

Proposed paradigm for bacterial involvement in carcinogenesis