Abstract IA02: Racial and gender-based survival disparities in head and neck cancer
Authors: Cullen Kevin 
Published: October 2015

Abstract
Background: Racial and gender disparities in the incidence and outcome of head and neck cancers have been known Men are much more likely to develop HNSCC than women (40,220 cases v 14,850 cases in the US in 2014). Racial outcome disparities have been observed in head and neck cancer with black patients consistently reported to have diminished survival compared to whites. Nationally, from 2003-2009, 5 year relative survival for oral cavity and pharyngeal cancer was 67% for whites and 46% for blacks. For laryngeal cancer, the relative survival was 64% for whites and 52 % for blacks (www.cancer.org/research/cancerfactsstatistics/cancerfactsfigures2014/). The etiology of this racial survival disparity appears to be multifactorial in origin. To investigate this further, we performed a retrospective analysis of HNSCC patients treated at the University of Maryland Greenebaum Cancer Center (UMGCC)
Methods: We retrospectively analyzed 1318 patients with first primary HNSCC treated at the UMGCC from 2000 to 2010. Demographic and clinical characteristics as well as overall survival (OS) were compared between black and white patients.
Results: Of the 1318 patients analyzed, 65.9% were white, 30.7% were black and 3.3% were other races. Striking differences in the distribution of patients by disease site were noted. Black patients were far less likely to present with oral cavity cancer (15.6% of cases) and far more likely to present with laryngeal or hypopharyngeal (65.6% of cases) cancer. White patients were more likely to have early stage (I and II) disease, especially in the oral cavity. In the full cohort, overall survival for black patients was significantly worse than for white patients (median 2.5 years vs. 4.8 years, p&lt;0.0001). Multivariable Cox regression analysis showed black patients had significantly worse survival accounting for age, gender, stage, primary site, tobacco and alcohol consumption. Black patients had worse median OS in both oral cavity (5.7 vs 3.2 years, p&lt;0.0001) and oropharyngeal cancer (4.9 vs.2.1 years p&lt;0.0001). However, multivariable analysis showed that race was only significantly associated with survival in oropharyngeal cancer. There was no difference in OS between races in laryngeal or hypopharyngeal cancer. The difference in survival in oral cavity cancers resulted from the larger proportion of white patients with Stage I or II disease. White patients with oral cavity and oropharyngeal cancer were more likely to have surgery as primary treatment than blacks reflecting the higher prevalence of early stage disease. No difference was noted in the rates of chemoradiotherapy between black and white patients with advanced disease in oropharynx, hypopharynx and larynx.
Analysis of HPV associated oropharyngeal cancer over time shows that these cancers are much more common in blacks than in whites, but are increasing for both races.
Our data are corroborated by SEER data and other investigators. Interestingly between 1975 and 2007 the incidence of oral cavity cancer as a whole fell by 51%. For black women, the incidence of oral tongue cancer fell by a similar 55% during that time period. The incidence of oral tongue cancer for white women increased by 21% during the same period, driven significantly by a 111% increase in young white women. (Patel 2011, JCO 29: 1488). The etiology of this increase in oral tongue cancer among white women does not appear to be associated with HPV or smoking and its causes are unclear.
Conclusion: We observed striking differences in site of disease, stage at presentation and survival comparing black and white patients. The difference in survival between the two groups overall is driven by a large difference specifically in oropharyngeal cancer. This is consistent with previous reports of differences in the incidence of HPV in the two ethnic groups, but likely reflects other factors as well. An emerging gender and racial disparity in the incidence of oral tongue cancer remains unexplained.
Citation Format: Kevin Cullen. Racial and gender-based survival disparities in head and neck cancer. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr IA02.