Increasing lung cancer mortality rates in the elderly: a manifestation of differential survival.

Lung cancer mortality rates in the elderly are increasing. Using published United States mortality data, annual age-specific lung cancer mortality rates from 1968 to 1989 were determined for age groups over age 50 and compared to corresponding annual age group population sizes. Rising lung cancer mortality rates among the elderly in the United States from 1968 to 1989 were increasingly dependent, with increasing age, upon increasing age group population size. This finding suggests that differential survival, and its effect upon the surviving gene pool in an aging population, may account for observed increasing lung cancer mortality rates in recent successive elderly cohorts. That is, increasing lung cancer mortality rates in the elderly may reflect changes in the genetic susceptibility of the surviving population rather than changes in environmental exposures.