Occurrence of field cancerization in clinically normal oral mucosa: A systematic review and meta-analysis

OBJECTIVE: The purpose was to describe whether there are field cancerization (FC) indicators in clinically normal mucosa opposite to primary oral squamous cell carcinoma (OSCC). METHODS: A search of the Cochrane Library, PubMed, Embase, Web of Science, Scopus, and Livivo databases was performed on June 12, 2022, which retrieved 152 records without duplicates. Studies that analyzed FC in biopsies in clinically normal tissue opposite to primary OSCC were included. The search was conducted under the PRISMA guideline and the protocol was registered in PROSPERO (CRD42017077125). RESULTS: 73.284 %; n = 205). p53 and Ki-67 immunohistochemical analysis may be predictive for detecting changes. There was p53 immunoexpression in 41.3 % of cases (p = 0.872) (n = 55), ki-67 immunoexpression (< 20 %) in 68 % (p = 0.001) (n = 97) and ki-67 immunoexpression (> 20 %) in 28.4 % of cases (p = 0.000) (n = 110). CONCLUSIONS: The findings suggest that FC can occur, and there are histopathological changes in clinically normal tissue opposite to primary OSCC. Nevertheless, the review showed that more longitudinal studies on FC are needed to draw a conclusive indication of the occurrence of FC in oral tissues opposite to OSCC.