Differences among oral carcinomas arising de novo from those associated with oral potentially malignant disorders: a systematic review and meta-analysis.

OBJECTIVE: To analyze the frequency of sequential oral squamous cell carcinomas (s-OSCC), preceded by oral potentially malignant disorders, and OSCC de novo (OSCC-dn) and explore differences in their clinicopathologic presentations.

STUDY DESIGN: A structured electronic search strategy identified studies that analyzed frequency, clinical, biological, demographic, biomarkers, and prognostic features of s-OSCC and OSCC-dn according to PRISMA guidelines in PubMed, Scopus, Cochrane Library, and Google Scholar, up to January 31, 2023. Inclusion criteria were original English, Spanish, Portuguese, French, Italian, and German cross-sectional, cohort, and case-control studies. The quality of studies was assessed using the Agency for Research and Health Quality tool and the Newcastle-Ottawa Scale tool.

RESULTS: The final selection included 40 studies. OSCC-dn and s-OSCC represent, respectively, 71% and 29% of cases of OSCC (P = .00), showing a higher percentage of T1 or of T1+T2 in s-OSCC (P < .0001). The association meta-analysis showed OSCC-dn with a significant association. The meta-analysis showed that s-OSCC was significantly associated with smaller tumor size, absence of distant metastases, relapses, male sex, and tumor sites different from tongue; and OSCC-dn was associated with more advanced tumor size, more regional and distant metastases, more advanced stages, and worse survival.

CONCLUSIONS: S-OSCC was less frequent than expected. OSCC-dn seems to have specific clinical, biological, and prognostic features. Future perspectives on oral cancer prevention should address novel approaches and alternatives to screening, such as urgent referral of OSCC-dn.