Defining the Young Oral Cavity Cancer Patient

Abstract

Emerging data have suggested an increased incidence of oral cavity squamous cell (OCSCC) in young patients without traditional risk factors. However, the cause remains unclear. Here we seek to further characterize the young OCSCC patient population and better define the transition from young to traditional oral cancer patients. The Surveillance, Epidemiology, and End Results (SEER) database (2004-2011) and the University of Michigan Head and Neck Cancer Epidemiology Database (UMHNC) (1998-2016) were queried for cases of OCSCC (excluding stage IVb and Lip) resulting in 9,766 and 232 patients respectively. Additional clinical and histopathologic variables were collected. Data were extracted from the electronic medical record and research databases, with institutional IRB approval. Descriptive statistics and Kaplan-Meier survival analyses were performed using SPSS Statistics Version 24 (IBM Corp, NY). Using the SEER database, we identified two significant demographic shifts in OCSCC that described 40 years of age as a transition point defining the young cohort. There is a transition in the male to female ratio from near equivalence (1.2:1) in young patients to a greater male predominance (1.6:1) in patients over 40 (P =.002). The second shift is seen in anatomic subsite, where the vast majority of tumors arise in the oral tongue among young patients compared to a more even distribution of subsites in traditional patients (90.3% vs 58.5% oral tongue primary; P < .001). These demographic trends were validated in the UMHNC cohort, where patients in the young (<40) group showed a male: female ratio of 0.8:1.0 (compared to 1.3:1.0) and 84.1% (compared to 35.6%) of tumors arising from the oral tongue (P =.183 and <.001, respectively). Traditional patients were significantly more likely to have exposure to known risk factors for OCSCC (tobacco use 81.0% vs 43.2%, P<.001; alcohol use 52.1% vs 9/1%, P<.001). In the SEER cohort, the 5-year disease-specific (DSS) of young and traditional patients did not differ significantly among stage III and IV patients, although both remained poor for stage IV disease at 49% and 37%, respectively. We have objectively identified 40 years of age as a transition point for two distinct features for young, low-risk OCSCC patients, including a higher proportion of female patients and tumors airing from the oral tongue, using national cohort data validated with our institutional data. DSS does not differ between young and traditional patients for advanced disease and remains very poor. These patients comprise an interesting and important cohort given their lack of traditional risk factors yet similarly poor outcomes. By defining an objective measure of age, further investigation into the biologic mechanisms for tumorigenesis in this group is essential for characterizing disease in these patients.