Long-term Survivorship and Non-cancer Competing Mortality in Head and Neck Cancer: A Nationwide Population-Based Study in South Korea

PURPOSE: As the survival of head and neck cancer (HNC) improves, survivors increasingly confront non-cancer–related deaths. This nationwide population-based study aimed to investigate non-cancer–related deaths in HNC survivors. MATERIALS AND METHODS: Data from the Korean Central Cancer Registry were obtained to characterize causes of death, mortality patterns, and survival in patients with HNC between 2006 and 2016 (n=40,890). Non-cancer-related mortality relative to the general population was evaluated using standardized mortality ratios (SMRs). The 5- and 10-year cause-specific competing risks probabilities of death (cumulative incidence function, CIF) and subdistribution hazards ratios (sHR) from the Fine-Gray models were estimated. RESULTS: Comorbidity-related mortality was frequent in older patients, whereas suicide was predominant in younger patients. The risk of suicide was greater in patients with HNC than in the general population (SMR, 3.1; 95% confidence interval [CI], 2.7 to 3.5). The probability of HNC deaths reached a plateau at 5 years (5-year CIF, 33.9%; 10-year CIF, 39.5%), whereas the probability of non-HNC deaths showed a long-term linear increase (5-year, CIF 5.6%; 10-year CIF, 11.9%). Patients who were male (sHR, 1.56; 95% CI, 1.41 to 1.72), diagnosed with early-stage HNC (localized vs. distant: sHR, 1.86; 95% CI, 1.58 to 2.21) and older age (65–74 vs. 0–44: sHR, 6.20; 95% CI, 4.92 to 7.82; ≥ 75 vs. 0–44: sHR, 9.81; 95% CI, 7.76 to 12.39) had an increased risk of non-cancer mortality. CONCLUSION: Non-HNC–related deaths continue increasing. HNC survivors are at increased risk of suicide in the younger and comorbidity-related death in the older. Better population-specific surveillance awareness and survivorship plans for HNC survivors are warranted.