Loss of Heterozygosity in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma - A Scoping Review

This scoping review was conducted to ascertain the loss of heterozygosity (LOH) signatures reported in Oral Potentially Malignant Disorders (OPMD) and Oral Squamous Cell Carcinoma (OSCC), in the literature in the last fifty years.

The Joanna Briggs Institute recommendations (2023) for scoping review were used to extract, analyze, and present the results. The review was reported according to the PRISMA guidelines for Scoping Reviews (PRISMA-ScR). The most commonly reported genes associated with LOH in OPMD and OSCC are discussed. The Gene Ontology functional enrichment analysis gives the significance of the protein-protein interactions (PPI) of these genes using the STRING database.

An exhaustive database search of the title, abstract, and full-text screening consistent with the eligibility criteria yielded 277 studies. LOH commonly studied in OPMD and OSCC include p53 gene, p16 gene, adenomatous polyposis coli gene, retinoblastoma (Rb) gene, fragile histidine triad (FHIT) gene and phosphatase and tensin homolog (PTEN) gene. Chromosome loci involving 17p, 9p, 5q, 13q, 3p, and 10q were frequently reported in OPMD and OSCC. PPI analysis demonstrated strong evidence of p53 interaction with p16, FHIT, and Rb.

Distinctive signatures of LOH are seen in OPMD and OSCC. The LOH patterns identified in this scoping review underline the significance of advanced molecular techniques and the need for long-term prospective cohorts to understand LOH pathophysiology in oral carcinogenesis to enable their usefulness as biomarkers in early diagnosis, treatment, and prognostication of oral cancer.