Competing causes of death in the head and neck cancer population

The increasing survivorship of head and neck squamous cell carcinoma (HNSCC) comes with a risk of death from other causes, known as competing causes. The demographics of HNSCC are also evolving with increasing incidence of Human Papillomavirus (HPV) associated tumors. This study describes competing causes of death for the HNSCC population compared to the general population and identifies associated risk factors.

Adult patients with first mucosal HNSCC (2004-2011) were identified from the Surveillance, Epidemiology and End Result database. Competing causes of death were compared to reference populations using proportion of deaths and Standardized Mortality Ratios (SMR). A multivariable competing risk survival analysis yielded subdistribution hazard ratios (HR) for competing mortality.

Of 64,598 HNSCC patients, 24,602 (38.1%) were deceased including 7142 deaths (29.0%) from competing causes. The most common were cardiovascular disease, lung cancer, and other cancers. All relative mortality rates were elevated, especially liver disease (SMR 38.7; 95% CI: 29.4-49.3), suicide (SMR 37.1; 95% CI: 26.1-48.6), and subsequent primary cancers (SMR 7.5; 95% CI: 6.78-8.32). Demographic and tumor factors independently increased risk of competing mortality, including age (HR per 5years 1.24; 95% CI: 1.22-1.25), sex (male HR 1.23; 95% CI: 1.16-1.32), race (Black HR 1.17; 95% CI: 1.09-1.26), insurance (uninsured HR 1.28; 95% CI: 1.09-1.50), and marital status (single HR 1.29; 95% CI: 1.21-1.37).

Nearly one in three HNSCC patients died from competing causes. When developing long term survivorship regimens for HNSCC patients, clinicians should be familiar with this population's specific risks.