Introduction
On a global scale, head and neck cancers (HNC) account for 650,000 new cancer cases and 330,000 deaths annually (1,2). In the United States, HNC encompasses three percent of all cancers and accounts for 53,000 new cases and 10,800 deaths annually (1,3). Recent case reports have suggested that the age at diagnosis may be getting younger for many of the HNC subsites (12-18). However, there is no large scale study in the literature evaluating this possibility. Although there is substantial data documenting risk factors, genetic markers of HNC and trends of HNC epidemiology, we have been unable to find published data that clearly identifies whether there has been a true increase or decrease in the proportion of young patients diagnosed with HNC. This study is different from the published literature and unique in that it tracks the relative change in prevalence between HNC age cohorts to highlight proportional changes amongst age groups over time. We show the proportion of patients within age-cohorts diagnosed with HNC, stratified by primary tumor site subtype, throughout the last few decades. Evaluated HNC subtypes include oral cavity, larynx, oropharynx and hypopharynx. The purpose of this study is to determine whether HNC patients are truly “becoming younger”.
Currently, the incidence of HNC is decreasing in the United States (4,5). This is attributed to reduction of tobacco use in the general population (6,7,8). However, the incidence of oropharyngeal squamous cell carcinoma, a subset of HNC, has increased over the last few decades (4,5,9,10). This has been linked to higher prevalence of HPV infection of the upper airway (4,5,10,11). There is currently contradicting data on the trends of other subsets of HNC. Population studies show that incidence of all subsets of HNSCC, besides OPSCC, is actually decreasing (4,5), but several independent studies report an alarming increase of patients younger than 40 being diagnosed with squamous cell carcinoma of the larynx and oral cavity (12-18). This is our primary point of interest – to determine whether a larger proportion of young patients are being diagnosed with HNC than before, even though overall HNC incidence is decreasing.
With the reduction of tobacco use and increase of upper airway HPV infection in the U.S. in recent decades, the risk factors for HNC have changed dramatically. This study breaks down, over time, HNC subtypes by age cohorts to clarify whether there are significant changes in the . Any possible changes in the age distribution of HNC could help uncover underlying risk factors. Further, this could guide physicians and researchers to develop more age-specific prevention and intervention methods.