Racial disparities in squamous cell carcinoma of the oral tongue among women: A SEER data analysis

Objectives: The incidence of oral tongue cancer (OTC) in the US is increasing in women. To understand this phenomenon, we examined factors influencing OTC incidence and survival. Materials and methods: We identified women diagnosed with OTC that were reported to the Surveillance, Epidemiology and End Results (SEER) program from 1973 to 2010. Incidence and survival rates were compared across metropolitan, urban and rural residential settings and several other demographic categories by calculating rate ratios (RRs) with the corresponding 95% confidence intervals (CIs). We examined changes in incidence of OTC across racial groups using joinpoint analyses since 1973, and assessed factors associated with survival. Patients diagnosed prior to 1988 were excluded from the survival analysis due to lack of data on treatment. Results: OTC incidence in white females demonstrated a significant upward trend with 0.53 annual percentage change (APC) between 1973 and 2010. The change seems to be limited to white women under the age of 50 years and appears to have become pronounced in the 1990s. For African Americans (AA) on the other hand, the incidence has decreased. Incidence estimates did not differ in metropolitan, small urban and rural setting. The 1-, 5- and 10-year relative survival estimates were 86%, 63% and 54% for white women, and 76%, 46% and 33% for AA women. On multivariable analyses factors significantly associated with better survival included lower stage, younger age, married status, and receipt of surgical treatment, but not race. Conclusion: The racial disparity in OTC survival is evident, but may be attributable to the differences in stage at diagnosis as well as access to and receipt of care. As the incidence of OTC is increasing in young white women, identifying the risk factors in this group may lead to a better understanding of OTC causes. (C) 2015 Elsevier Ltd. All rights reserved.