Incidence trends of kidney cancer in China from 1990 to 2019: A joinpoint and age-period-cohort analysis

Background: Occupational carcinogens, smoking, and obesity are believed to be the main causing agents of kidney cancer. China is undergoing rapid industrialization, and hence the people's lifestyles have witnessed tremendous changes. However, the trend of kidney cancer incidence during the late 20th and early 21st centuries remains unexplored in China. Materials and methods: Data from the Global Burden of Dis-eases (GBD; 2019) was retrieved for the incidence of kidney cancer from 1990 to 2019. The rates of disease average annual percent-age changes (AAPC) were assessed using joinpoint regression analysis. Age-period-cohort (APC) model was used to assess age, period, and cohort effects on the incidence of the disease simultaneously. Results: An increase in age-standardized incidence rates (ASIR) of kidney cancer was observed from 1990 to 2019 in total residents (1.33 - 4.24), men (1.56 - 6.15), and women (1.11 - 2.31) per 100,000 population suggesting a more obvious increase in males than in females. A consistent increase in age effects was observed in all age groups, especially in males. On the other hand, the 70 - 74 age group in females showed greater age effects. In addition, the period effects analysis showed that the incidence of kidney cancer increased with time. Moreover, the analysis of cohort effects showed a decrease in the disease in birth cohorts, especially before 1940. Conclusion: The incidence of kidney cancer is in-creasing rapidly in China. The kidney cancer burden will rise in the next decades due to population aging, environmental pollution, occupation, food safety, and so on. Results of this study suggest that more etiological studies should be performed to identify the driving factors for kidney cancer trends, and appropriate preventive measures should be implemented for the age-, period-, and cohort-related factors in the population.