Molecular basis of oral squamous cell carcinoma in young patients: Is it any different from older patients?

Oral squamous cell carcinoma (OSCC) is the commonest subtype of oral cancer, mainly affecting older patients. It used to be a rare disease among individuals younger than 40 years, but recently increased incidences in this age group are being reported worldwide. The pathogenesis of OSCC affecting young patients remains controversial, and the well-known etiological factors for oral cancer, tobacco, and alcohol use are believed to play a minor role in the carcinogenesis of the neoplasm, suggesting that the etiology and the molecular basis of OSCC may differ between younger and older patients. Although several molecular markers and chromosomal abnormalities have been demonstrated to differ between both groups, most of the studies have failed to find significant differences. Moreover, divergent results have also been obtained regarding the presence of high-risk human papillomavirus infection in OSCC of young patients. Given these contradictory results and the limited methodological approaches of the majority of the studies, the exact difference between both age groups remains to be fully established. In this review, we evaluate the available data to establish the current evidence that might support the hypothesis that the molecular basis of OSCC in young patients (especially those under 40 years) differ from the older patients.