Lung cancer incidence rates by histologic type: an example of trends in Eastern Europe - Slovakia 1978-95

During the period 1978-1995 43206 cases of lung cancer-37967 in men and 523 9 in women - were recorded in Slovakia. Among 26240 microscopically confirm ed cases in men squamous cell carcinomas were the most frequent (57.1%) fol lowed by small cell carcinomas (18.3%) and adenocarcinomas (11.7%). In wome n from 3190 microscopically confirmed cases squamous cell carcinomas and ad enocarcinomas had nearly the same frequency (31.9% and 32.2%, respectively) , followed by small cell carcinomas (16.1%). In men after a marked increase of overall lung cancer incidence and mortality the rates started to flatte n and even decline from the early 1990s. The main histologic types peaked i n the late 1980s and declined thereafter but showed increase of percentage change when the rates at the beginning and the end of the studied period we re compared; the highest one was marked for adenocarcinomas. The correspond ing rates in women were much lower, but their increase was more pronounced than in men. Adenocarcinomas showed almost twofold increase in women during the first time-period of the study but after peaking in 1984-1986 they sta bilized, while squamous cell carcinomas continued to increase also in recen t years. The analysis of incidence rates by age groups showed that the init ial increase and subsequent decrease of all microscopically confirmed cases in men as well as their gradual increase in women was influenced mainly by the trends of squamous cell carcinomas in younger age groups in men and in all age groups in women. Absence of higher increase and proportion of aden ocarcinomas in Slovakia in both sexes could probably be explained by delaye d introduction of filter tipped and low tar cigarettes.