Lung cancer mortality trends among women across Spain: the role of birth cohorts in diverging regional patterns

Smoking among Spanish women has increased during the last 50 years and is considered by some authors a modern epidemic. However, mortality risk by cohorts may differ at a regional level, given that health inequalities (and the determinants of smoking and its consequences) are regionally patterned. We applied an Age-Period-Cohort model to identify birth cohort effects on female lung cancer mortality in Spain. We found a strong linear increase in lung cancer mortality during the 1980–2019 period in all regions. Cohorts born between 1935 and 1955 presented a higher relative risk of death at a national and subnational level. However, we found diverging cohort patterns across regions afterward, with some regions presenting a slight mortality improvement (or stagnation) in their youngest cohorts, while in other regions mortality kept increasing. This suggests that inequalities in lung cancer mortality in Spain among women are not only generationally based, but that generational risks also vary across space. Some of the regions that presented improvements in mortality among its younger cohorts are Madrid, Navarra, and the Basque Country, which are some of the wealthiest in the Country. While speculative, this could imply that improvements at a regional level might be associated with factors related to structural conditions that result in the adoption of healthy behaviors.