Tobacco use and its impact on survival in young patients with oral cancer.

Background: Tobacco is a major risk factor associaetd with developing oral factor. Recent studies have shown that the age of onset, especially in Asia, is reducing. This study was to determine if tobacco exposure correlated with prognosis in oral squamous cell carcinoms (OSCC) based on age at diagnosis.
Methods: Six hundred and forty three patients of OSCC treated in our institution were divided into four groups, younger patients (≤45 years) with or without tobacco exposure and older patients (>45 years) with or without tobacco exposure, and compared with respect to prognostically relevant variables, disease-free survival (DFS) and overall survival (OS). Survival analysis was performed.
Results: The percentage of those with tobacco exposure was comparable in both age groups. Tobacco correlated with known pathological determinants in OSCC; however, perineural invasion, lymphovascular invasion, and extranodal extension were significantly more common in the young. On survival analysis, tobacco exposure impacted OS (P = 0.04) and DFS (P = 0.03) in patients ≤45 years, and not in older patients >45 years. On multivariate analysis, tobacco exposure in the young was significantly associated with recurrence (P = 0.03, hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.07-2.94) but not survival.
Conclusion: Younger patients with a history of tobacco use have a significantly higher risk of recurrence and mortality due to OSCC, but this difference could not be attributed to any of the known prognostic determinants in OSCC. Younger patients also had more adverse pathological features. Whether this occurs because of altered disease biology or pathways of carcinogenesis in the young with tobacco exposure is unknown. Younger tobacco users with oral cancer are more likely to have a poor prognosis.