[Effect of smoking on the development of various histological types of lung cancer]

The aim of this clinically controlled trial was to assess the effect of different smoking patterns on development of different histological types of lung cancer. The study group consisted of 1,432 subjects that died due to lung cancer in the years 1980-1987. 627 of these had the histological type of the cancer determined; 54% had squamous cell cancer, 24% small cell lung cancer (SCLC), 17% adenocarcinoma. The control group consisted of 1,343 subjects that died due to other causes. Medical and social history was taken from the families of the deceased. The results of the analysis demonstrate that lung cancer development is related to smoking although differences were seen in the different types of cancer. The calculated risk of a smoker developing lung cancer-squamous cell and SCLC was respectively 15.4 and 13.5 while for adenocarcinoma it was much lower--3.1. Important differences were seen in ex-smokers developing squamous cell lung cancer and SCLC. The risk of developing squamous cell lung cancer and SCLC in this group was 89% and 88%, and adenocarcinoma only 64%. This suggests that adenocarcinoma is related more to environmental factors than the other two types of lung cancer.