Quantifying the Mediation Effect of Disease Stage on Racial Disparities in Head and Neck Cancer Survival

There are significant racial and ethnic disparities in head and neck cancer (HNC) survival. Disparities in cancer stage appear to account for some of the disparities in survival. However, the proportion of the survival disparities mediated by cancer stage is unclear. This study aimed to quantify the mediation effects of stage at diagnosis on racial/ethnic disparities in HNC survival using data from the California Cancer Registry. We found that T3-4 disease accounted for 36.3% (95% CI 15.6% to 57.0%) of the association between Black (versus White) and worse OS, and for 44.2% (95% CI 10.9% to 77.4%) of the association between Black (versus White) and worse DSS. This suggests that interventions aimed at improving access to care and early detection of malignancies may have highest impact in reducing racial/ethnic disparities in HNC survival. Future studies are needed to further understand factors that drive racial disparities in HNC stage at diagnosis, and to inform the development of intervention strategies to address these disparities.