Lung cancer screening-its present situation, problems and perspectives

Mortality from lung cancer is increasing at the rate of more than 7% annually, becoming 31.7 per 100,000 among males in 1983. Out of 3,278 cities, towns and villages all over Japan, 21% of them were carrying out mass screening programs for lung cancer in 1982, and many other municipalities have followed suit over the last few years. Lung cancer screening has spread because of the widespread use of mass miniature radiophotography (MMR) for tuberculosis which has been adopted for use for lung cancer on the one hand, and because many research programs have revealed rather high detection rats with excellent prognosis for occult lung cancer using sputum cytology on the other. As screening procedures differ from one area to another, evaluation of the various methods of screening has been made. Emphasis is laid on the importance of double reading of X-ray film, comparisons of X-ray findings with those of previous one, criteria of screening for doubtful lung cancer cases, criteria for high-risk groups in sputum cytology, and so on. Epidemiological effects of lung cancer screening have not yet been confirmed, but so many lung cancer cases have been detected and treated, that a realistic approach for the improvement of screening programs was discussed.