Is micronucleus assay in oral exfoliated cells a suitable biomarker for predicting cancer risk in individuals with oral potentially malignant disorders? A systematic review with meta-analysis.

This systematic review (SR) with meta-analysis aimed to evaluate the scientific data related to cytogenetic damage in oral exfoliated cells of patients diagnosed with oral potentially malignant disorders (OPMDs). The SR was conducted according to the PRISMA-P guidelines. The PICOS (Participants, Intervention, Comparison, Outcome, and Study Design) strategy was used to answer the question: "Is micronucleus assay in oral exfoliated cells a suitable biomarker for predicting cancer risk in individuals with OPMDs?" The search strategy was performed in the following electronic databases: PubMed, Medline, Scopus and Web of Science. The comparisons were defined as standardized mean difference (SMD), and 95% confidence intervals (CI). The quality of included studies was assessed using the EPHPP (Effective Public Health Practice Project). The GRADE tool was also utilized to assess the quality of evidence of the SR. A total of 110 potentially relevant studies were selected through the search strategy. After screening titles and abstracts, 20 full-text manuscripts were assessed for eligibility and three observational studies were included in the meta-analysis. After reviewing the 20 studies, 13 were considered weak. The meta-analysis data revealed a statistically significant difference in oral micronucleated cells by patients with OPMDs when compared to control (SMD=1.77, 95% CI, 0.36-3.18, p = 0.01), with a Tau2 = 1.97; Chi2 = 66.64, and p < 0.001. Patients with OPMDs had a positive response related to mutagenicity in oral cells compared to control patients. However, SR was not able to validate the micronucleus assay as a putative biomarker in individuals with oral potentially malignant disorders since the majority of studies were considered weak based on high risk of bias.