Age-Period-Cohort and Decomposition Analyses of Nasopharyngeal Cancer Mortality in Urban China from 2004 to 2019, with Projections for the Next 15 Years

This study aimed to assess the age, period, and cohort effects on long-term trends in nasopharyngeal cancer (NPC) mortality in urban China from 2004 to 2019 and to project mortality patterns for the next 15 years. Data on NPC were obtained from the Chinese Cancer Registry Annual Reports covering the years 2004-2019. The age-period-cohort model was applied to quantify trends in NPC mortality, including estimates of the overall annual percent change (net drift), age-specific annual percent changes (local drift), the longitudinal age-specific rate (longitudinal age curve), and the relative risks associated with different periods and birth cohorts. To further explore the drivers of disease burden, decomposition analysis was applied to separate the effects of population aging and growth. Finally, a Bayesian APC model was used to project NPC mortality for the next 15 years. The number of deaths and age-standardized death rates (ASDR) for NPC are higher in males than females. The ASDR for NPC decreased by 22.17% in males and 26.03% in females, respectively. The net drifts of mortality were below 0 (males: -0.82% [95% CI: -1.51 to -0.12], females: -1.23% [95% CI: -2.14 to -0.31]). The longitudinal age curve demonstrated increased NPC mortality with age groups for both males and females, except aged 85+ years group. The period RR indicated a decreased risk of NC mortality in both males and females. Cohort RR indicated that later birth cohorts have a lower risk of death from NPC compared to earlier birth cohorts in both males and females. Population growth and aging are the main driving factor behind the increased burden of NPC. According to projections, the ASDR of NPC among males and females aged 15 years and above in urban China is expected to decline to 1.77 and 0.61 per 100,000, respectively, by 2034. The decline in ASDR in urban areas indicates that China’s measures for the prevention and treatment of NPC are effective. However, the increasing population and aging demographic are driving factors behind the rising burden of NPC. Future policy decisions should take into account the growth of the urban population, the elderly and males.