[Trends and age-period-cohort analysis of leukemia incidence in Qidong from 1972 to 2021].

Objective: To describe the epidemiological characteristics and trends of leukemia incidence in Qidong between 1972 and 2021, and provide guidelines for prevention and control measures and strategies. Methods: The cancer registry data was collected and analyzed on leukemia incidence during 1972-2021 in Qidong by sex, age and time. Crude incidence rate (CR), China age-standardized rate (ASRC), world age-standardized rate (ASRW), and average annual change percentage (AAPC) was calculated by Joinpoint software. Age-period-cohort (APC) model was used to analyze the influence of age, period and birth cohort on the changes in the incidence trend of leukemia patients. Results: From 1972 to 2021, there were 2 948 patients with leukemia in Qidong, accounting for 2.00% of all cancer new cases, CR of leukemia was 5.26/10⁵, ASRC was 4.34/10⁵, ASRW was 4.35/10⁵. The truncated incidence of 35-64 years old was 5.29/10⁵, the cumulative incidence rate between the ages of 0 and 74 years old was 0.40%, the cumulative risk was 0.40%. There were 1 608 male patients, the CR, ASRC, and the ASRW were 5.81/10⁵, 4.88/10⁵ and 4.85/10⁵. The number of female patients were 1 340, and the CR, ASRC, and the ASRW were 4.71/10⁵, 3.86/10⁵ and 3.91/10⁵, respectively. Temporal trends indicated significant upward trends in ASRC among both gender, males and females with AAPC values of 1.41% (P＜0.001), 1.15% (P＜0.001), and 1.73% (P＜0.001), respectively. The results of the APC model showed that the average net drift value of leukemia incidence in all age groups was 1.57% (95% CI, 1.24%-1.89%), and the highest value of local drift was 3.20% (95% CI, 1.63%-4.78%) in the 80~ years old group. The incidence of leukemia increased with age. With the passage of time, the risk of leukemia incidence increased gradually compared with the rate ratio of leukemia incidence (risk ratio [RR], 1.00) in 1992-1996, the RR of leukemia incidence increased from 0.70 during 1972-1976 to 1.57 during 2017-2021. The later the cohort was born, the greater the risk of leukemia incidence compared with the relative risk of leukemia incidence (RR, 1.00) in 1952-1956 cohort, the RR of leukemia incidence increased from 0.24 in the 1892-1896 cohort to 2.73 in the 2017-2021 cohort. Conclusions: The incidence of the leukemia has presented a rising trend in the past fifty years. Leukemia incidence increased with age, and the period and cohort effects on the risk of incidence increase. Further research is needed to investigate the risk factors related to leukemia.