Trends and age-period-cohort analysis of upper aerodigestive tract and stomach cancer mortality in Lithuania, 1987-2016

Objectives: Lithuania has among the highest mortality rates for upper aerodigestive tract (UADT) and stomach cancer in Europe. The aim of this study was to analyze trends during the period 1987-2016 in Lithuania, evaluating the effect of birth-cohort, period, and age. Study design: Observational time trends study. Methods: Data on numbers of deaths and population size by each calendar year in 5-year age groups in 1987-2016 were obtained from the WHO mortality database. Joinpoint regression analysis was used to evaluate changes in time trends. Age-period-cohort analysis was performed to assess age, calendar period of death, and birth-cohort effects. Results: UADT cancer mortality in men increased between 1987 and 1993, annual percentage change (APC) = 6.6% (95% confidence interval [CI]: 3.8, 9.4), and was stable thereafter, APC = 0.3% (95% CI: 0.0, 0.6). The age-standardized mortality rate (ASMR) was 23.6/100,000 in 2016. In women, rates increased steadily by 1.6% (95% CI: 0.9%, 2.3%) per year from 1987 to 2016, ASMR = 2.3/100,000 in 2016. Age-period-cohort analysis showed statistically significant cohort effects in both sexes. In men, rates peaked in birth-cohorts born around 1952, declined in 1957-1962 birth-cohorts, and fluctuated in later birth-cohorts. In women, rates started rising in 1947 birth cohort and peaked in the 1967 birth cohort. Stomach cancer mortality declined throughout the study period in men by -2.4%, (95% CI: -2.6%, -2.1%) annually, and women by -2.8% (95% CI: -3.1%, -2.4%), ASMR = 16.1/100,000 and 6.0/100,000 in 2016, respectively. Birth-cohort effects were significant in both sexes. Rates decreased in cohorts born around 1920 onwards, but declines in the youngest generations have slowed in men and reversed in women. Conclusions: The birth-cohort effects in UADT and stomach cancer mortality trends imply that the elevated burden in Lithuania could be reduced by effective strategies targeting known risk factors. Further research in causes of unfavorable trends in younger cohorts is warranted. (C) 2021 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.