Age-period-cohort effect on lung cancer mortality in Spain, 1982–2021

•ASMR shows a marked decline since the mid-1990s in men, while in women, since the early 1990s, rates began to gradually increase, resulting in a narrowing of the gender gap.•In both sexes, there is a rapid increase in age-specific rates, with higher rates in men than women.•Birth cohorts of men born in the 1950s–1960s had the highest LC mortality rate, which then levelled off and began to decline in younger generations. Female mortality rates in cohorts born between 1902 and 1932 remained relatively stable but increased in the following generations.•The period effect shows a change in the trend of men’s mortality, which began to decline in the early 1990s. However, for women, there has been an increase in rates since the late 1990s.•Our findings imply that the decline in mortality among males will continue. The onset of the LC epidemic in women may have been due to a higher prevalence of women smokers in these cohorts. The aim of the study is to provide up-to-date information and evaluate the age-period-cohort effects of age-period cohorts on lung cancer (LC) mortality in Spain for the period 1982 to 2021. We analysed deaths by LC and population for the period 1982–2021, available from the Spanish National Institute of Statistics. The LC corresponds to code 162 and codes C33 and C34 of the 9th and 10th editions of the International Classification of Diseases, respectively. Age-period-cohort (A-P-C) modelling was applied to compute the net drift, local drift, longitudinal age curve, and rate ratios (RR) of each period and cohort. A-P-C analysis was performed using the A-P-C Web Tool provided by the National Cancer Institute of the United States. Estimated relative risk in the male birth cohorts has followed a steady downward trend in all cohorts born since 1922, showing an initial period (1922–1947) of slight decline, followed by a more marked decrease in the cohorts born during the period 1947–1977. In the younger cohorts (1977–1997), the decline appears to have stabilised. In women, a strong cohort effect is observed. In those born after the Spanish Civil War (1936 to 1939), the risk increased until it peaked in the 1960s, after which it started to decrease with the same intensity. Period RR in men decreased from 1987 to 1991 (1.1) to 2017–2021 (0.6), while period RR in women increased during this time (from 0.8 to 1.6). The cohort effect observed in women born after the Civil War suggests that the onset of the LC epidemic may have been due to a higher p