Gender and ethnic disparities in incidence and survival of squamous cell carcinoma of the oral tongue, base of tongue, and tonsils: a surveillance, epidemiology and end results program-based analysis.

BACKGROUND Squamous cell carcinomas (SCC) of the oral tongue (OT) and of the base of the tongue and tonsils (BTT) differ with respect to etiology, treatment and prognosis. Human papillomavirus has been linked to the increased incidence of BTT, yet, the trends in incidence of BTT and OT tumors among gender and ethnic origin groups have not been well examined. We sought to examine the trend in gender-, ethnic origin- and age-specific incidence of these tumors over time. METHODS Data were obtained from the Surveillance, Epidemiology and End Results Program of the US National Cancer Institute. We examined temporal trends in sex- and ethnic origin-specific incidence of SCC by calculating the annual percent changes followed by joinpoint analyses evaluating changes in trend. RESULTS While BTT increased in age-adjusted rates among white males with a more pronounced increase observed in the mid-1990s, white females experienced a significant increase in incidence of OT tumors. Patients with advanced OT carcinoma had a significantly lower survival compared to those with advanced BTT disease; however, patients with early-stage OT tumors had a better survival compared to patients with BTT. CONCLUSIONS While the increase in incidence of BTT tumors in white men is likely human papillomavirus driven, more studies are needed to elucidate the increasing incidence of OT tumors in white women. The differences in outcomes across ethnic origin groups are also described and discussed.