Recent trends in lung cancer mortality in the United States

Background: Previous age-period-cohort analyses of lung cancer incidence an d mortality rates in the United States have demonstrated a decrease in risk by birth cohort through 1950, consistent with declining trends in smoking prevalence. This study was conducted to examine recent lung cancer trends, including trends among the cohorts born after 1950. Methods: Lung cancer mo rtality rates from 1970 through 1997 for whites aged 24-83 years and for bl acks aged 30-83 years were investigated. Using age-period-cohort analyses w ith a-year age and 2-year calendar-period intervals, we examined changes in the slope of the trends in birth-cohort and calendar-period effects. All s tatistical tests are two-sided. Results: There was an unexpected, statistic ally significant moderation in the rate of decrease of the birth-SUBJECTS A ND METHODS cohort trend in lung cancer mortality for whites born after 1950 , with a corresponding smaller and statistically nonsignificant moderation for blacks. These data are consistent with smoking initiation rates: Rates of both cigarette and marijuana smoking initiation increased for children a ged 12-17 years from 1965 through 1977, There was a statistically significa nt decrease in the slope of the calendar-period trend for lung cancer morta lity in 1990 for both whites and blacks that was observed primarily in peop le 55 years of age and older. Conclusions and Implications: The birth-cohor t pattern of lung cancer mortality after 1950 appears to reflect the early impact of teenage cigarette smoking on lung cancer risk in people under the age of 45 years, although a contribution from marijuana smoking cannot be ruled out. This result provides additional support for increasing smoking c essation and prevention programs for teenagers, The calendar-period decreas e in lung cancer mortality after 1990 may reflect the long-term benefits of reductions in tobacco carcinogens in cigarettes and increases in smoking c essation beginning around 1960.