Overview on small cell lung cancer in the world: industrialized countries, Third World, eastern Europe.

Lung cancer cases were abstracted from cancer registries in 20 countries to study the distribution of small cell lung cancer around 1985. The international patterns of small cell lung cancer resemble those of squamous cell tumours, and of lung cancer as a whole. Cigarette smoking and occupational risk factors are more strongly associated with squamous and small cell lung cancers than with adenocarcinoma. Inspection of sex differences and time trends in incidence show some differences which may relate to a higher risk for small cell lung cancer in female smokers than in males, and a less rapid decline in risk on smoking cessation.