[Prevention of lung cancer--primary and secondary prevention]

Prevention consists of primary and secondary prevention. For primary prevention of lung cancer, smoking control is considered to be most important and effective. If the present level of smokers in adults Japanese (52.8% in males and 13.4% in females) is decreased to the 50% level of the present level as it was once planned in "the Healthy Japanese 21", 32.3% of lung cancer in males and 7.6% in females (25.5% in both genders) could be prevented. For secondary prevention of lung cancer, periodic lung cancer screening may be useful. If the coverage rate of lung cancer screening is elevated to 30-50%, 15-25% of lung cancer deaths will be prevented assuming the odds ratio of lung cancer death is 0.50 for those who received lung cancer screening. It was estimated that if both smoking control and lung cancer screening were promoted extensively in Japan, as much as 30 to 50% of lung cancer incidences/deaths could be prevented.