Can biomarkers identify oral leukoplakia at high risk of malignant transformation? : A systematic review

Introduction Oral squamous cell carcinomas (OSCCs) frequently develop from oral potentially malignantdisorders (OPMDs). Oral leukoplakia (OL) is a white lesion in the oral mucosa and the mostprevalent OPMD. Malignant transformation rates for OL to OSCC has recently been reportedto 9.8%. Tobacco and alcohol abuse are risk factors. Brush biopsies of OL is a valid noninvasivemethod with high diagnostic accuracy and an alternative to scalpel biopsies. It’s hardto estimate which OL malignifies. An important question is if there are biomarkers obtainedfrom the cells from brush biopsies which can predict the malignant transformation of OL. Aim To elucidate available biomarkers in oral keratinocytes collected from brush biopsies, toidentify OL at risk of malignant transformation and early-stage oral squamous cell carcinoma. Methods Systematic literature search in PubMed and Cochrane was made to find relevant studies. Asystem of “PICOS” was made for inclusion which focused on OL and OSCC, brush biopsiesand biomarkers. Results Initial search resulted in 817 studies, after assessment of titles, abstracts and full texts tenarticles were included. Included articles had a total of 795 brush biopsy samples andinvestigated 39 different biomarkers. Conclusion We found a heterogeneity and lack of standardized reporting of data among the studiesincluded. Examination of the studies published so far indicated that biomarkers that couldpredict the risk of malignant transformation in patients with OL are still in a discovery phaseand biomarkers with high sensitivity and specificity are still not recognized