Temporal Trends in Lung Cancer Mortality Across 48 Countries from 1950 to 2019: An Ecological Study

BackgroundThe widespread success of tobacco control policy and smoking cessation campaigns has led to considerable reductions in lung cancer mortality. However, it is currently not known how many more deaths might have occurred if not for the substantial progress made in lung cancer control.MethodsIn this retrospective study, we used age-specific population counts and lung cancer mortality rates from 1950 to 2019 (from 48 countries) from the Global Cancer Observatory. We estimated age-standardized mortality rates (ASMR), standardized to the WHO (2000-2025) Standard Population. Peak mortality was defined as the year when the maximum ASMR was reached for each country and sex. For each year in the period following peak mortality, the expected number of lung cancer deaths was estimated using peak-year age-specific mortality rates and age-specific population counts for that year. The number of avoided deaths was estimated as the difference between expected and observed lung cancer deaths in that period.ResultsLung cancer mortality peaked for males in all 48 countries but has yet to peak for females in 11 countries. There have been 3.08 million avoided lung cancer deaths since mortality rates peaked for many countries (2.93 million for males, 0.15 million for females). Across these countries, 21.4% and 4.3% of expected lung cancer mortality has been avoided since mortality peaked for males and females, respectively. Fourteen countries have reduced lung cancer mortality more than 25% for men, while only two countries have for women. There have been statistically significant reductions in lung cancer deaths for 46 out of 48 (96%) countries for men and 14 out of 48 (29%) countries for women.ConclusionThere has been a substantial number of lung cancer deaths avoided since mortality rates peaked for many countries, though the reduction in mortality has not been observed in all countries or equally for males and females.