A 50-year projection of lung cancer deaths among Japanese males and potential impact evaluation of anti-smoking measures and screening using a computerized simulation model.

The lung cancer death rate among Japanese males was projected for 50 years to the year 2041 by a computerized simulation model. Long-term effects of anti-smoking measures and mass screening on lung cancer deaths were also evaluated. The simulation showed that the age-adjusted lung cancer death rate would increase and reach a peak of 166 per 100,000 in 1989 and then decrease to 148 per 100,000 in 2003. It then shows an increasing tendency again, up to 255 per 100,000 in 2028. The smoking initiation rates estimated from the observed lung cancer death rates showed that the changes in death rates may be attributed to a lower smoking initiation rate among those born in the 1930's. Promotion of mass screening programs is effective more quickly than anti-smoking measures but the reduction in annual cancer deaths is expected to be only 11%, even if 100% participation is achieved by the year 2000. A reduction in smoking initiation rate, on the other hand, affects lung cancer deaths very slowly. It was predicted that a 1% annual reduction in smoking initiation rate would result in a 20% decrease in the number of lung cancer deaths in 2041. A smoking cessation program is intermediate with regard to promptness. The predicted reductions in lung cancer deaths in 2041 were 13%, 47%, and 66%, respectively, when the annual smoking cessation rate was increased from 0.46% (present status) to 1%, 3%, and 5%. In conclusion, the combined application of all three preventive measures seems essential to realize the most effective reduction in lung cancer deaths.