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.