Long-term trends of laryngeal cancer incidence and mortality in China from 2004 to 2019 by region: age-period-cohort analysis and 15-years projections

<b>Background</b> The aim of this study was to evaluate the incidence and mortality rates of laryngeal cancer (LC) across urban and rural in China, analyze its epidemiological characteristics, and project the disease burden for the next 15 years.<b>Methods </b>Data on incidence, death, age-standardized incidence rate (ASIR), and age-standardized death rate (ASDR) of LC were obtained from Chinese Cancer Registry Annual Report from 2004 to 2019. Joinpoint regression analysis and age-period-cohort models were used to assess trends in the incidence and mortality rates of LC and interpret its epidemiological characteristics. Decomposition analysis assessed the contributions of demographic and epidemiological factors to the evolving burden of LC. Finally, the ASIR and ASDR of LC were projected for the next 15 years using a Bayesian Age-Period-cohort model.<b>Results </b>From 2004 to 2019, the number of LC cases, deaths increased in Chinese Cancer Registry. During the study period, the ASIR of LC in urban and ASDR of LC in rural showed a down trend with estimate annual percent changes (EAPC) of -1.49% (95% confidence intervals [CI]: -2.11 to -0.87) and -1.32% (95% CI: -2.38 to -0.24). The impacts of age, period, and cohort on incidence and mortality rates varied between rural and urban areas. Population growth is the main driver of increased LC deaths in urban areas, while aging is the main driver in rural areas. The forecast predicts a decline in the ASIR of LC in urban areas, while it will rise in rural areas by 2034. The ASDR of LC is expected to decrease slightly in both urban and rural areas by 2034.<b>Conclusions </b>This study reveals the complex epidemiological characteristics of LC in urban and rural areas of China. Population growth and aging are the primary drivers of LC deaths in China. Over the next 15 years, the ASIR of LC is projected to increase in rural areas, necessitating the management of specific risk factors and the development of targeted public health strategies.<br>