A 50-YEAR PROJECTION OF LUNG-CANCER DEATHS AMONG JAPANESE MALES AND POTENTIAL IMPACT EVALUATION OF ANTISMOKING MEASURES AND SCREENING USINGA COMPUTERIZED SIMULATION-MODEL

The lung cancer death rate among Japanese males was projected for 50 y ears to the year 2041 by a computerized simulation model. Long-term ef fects of anti-smoking measures and mass screening on lung cancer death s were also evaluated. The simulation showed that the age-adjusted lun g 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 a n increasing tendency again, up to 255 per 100,000 in 2028. The smokin g initiation rates estimated from the observed lung cancer death rates showed that the changes in death rates may be attributed to a lower s moking initiation rate among those born in the 1930's. Promotion of ma ss screening programs is effective more quickly than anti-smoking meas ures but the reduction in annual cancer deaths is expected to be only 11%, even if 100% participation is achieved by the year 2000. A reduct ion in smoking initiation rate, on the other hand, affects lung cancer deaths very slowly. It was predicted that a 1% annual reduction in sm oking initiation rate would result in a 20% decrease in the number of lung cancer deaths in 2041. A smoking cessation program is intermediat e with regard to promptness. The predicted reductions in lung cancer d eaths in 2041 were 13%, 47%, and 66%, respectively, when the annual sm oking cessation rate was increased from 0.46% (present status) to 1%, 3%, and 5%. In conclusion, the combined application of all three preve ntive measures seems essential to realize the most effective reduction in lung cancer deaths.