Liver Cancer Mortality Over Six Decades in an Epidemic Area: What We Have Learnt

Background: There was rare data to describe decades’ long natural history or changes of a cancer. We describe and explore the characteristics and trend of liver cancer mortality in Qidong, China over the past 60 years. Methods: Mortality data of liver cancer in Qidong from 1958 to 1971 (death retrospective survey) and from 1972 to 2017 (cancer registration) were tabulated for the crude rate (CR), age-standardized rate (by China’s population, ASRC and by Worlld population, ASRW) and age-birth cohorts. The average annual percentage change (AAPC) was calculated by the Joinpoint Regression Program. Findings: The natural death rate during 1958-2017 decreased from 9‰ to 5.4‰ and then increased to 8‰; Cancer mortality rate rose continuously from 57/10 5 to 240/10 5 . Liver cancer mortality increased from 20/10 5 to 80/105, and then dropped to less than 52/105 in 2017. Liver cancer deaths in 1972-2017 accounted for 30.53% of all cancers, with CR of 60.48/105, ASRC of 34.78/105, and ASRW of 45.71/105. The truncated rate of 35-64 was 104.06/105, cumulative mortality rate of 0-74 years, and cumulative risk rate were 4.79% and 4.68%, respectively. The CR for males and females were 91.86/105 and 29.92/105, respectively, with a sex ratio of 3.07:1. From 1972 to 2017, the AAPC of the ASRW derived by the Joinpoint analysis was -1.3%, in which -1.5% for men and -1.0% for women. The AAPC of joinpoints was -1.8% for both sexes, and -1.8% for males, -1.4% for females, respectively. Period analysis shows that the age-specific mortality rates of the age groups under 54 years old had a significant decreasing trend. Birth cohort analysis showed that the mortality rate of liver cancer in 40-44, 35-39, 30-34, 25-29, 20-24, 15-19 years cohort decreased, but the rates in 70-74, and 75+ were increased. Interpretation: The crude mortality rate of liver cancer in Qidong has experienced trends from lower to higher levels, and from continued increase at a high plateau to most recently a gradual decline, and change greatest in younger people. Many years of comprehensive prevention and intervention measures may have influenced the decrease of the liver cancer epidemic in this area. The reduction of intake levels of aflatoxin might be one of the most significant factors as evidenced by the decline of exposure biomarkers in this population. Funding Statement: The US National Institutes of Health through grants R01 CA196610 and R35 CA197222, the Chinese National Key Projects (2008ZX10002-015, 2008ZX10002-017, 2012ZX10002009), the Scientifc Research Projet of “333 Project” in Jiangsu (BRA2019030), and the Nantong Science and Techonology Project (MS22019008). Declaration of Interests: The authors declare no competing interests related to this study.