Educational differences in lung cancer mortality in male smokers.

BACKGROUND To assess the extent of lung cancer mortality differentials by education while adjusting for exposure to tobacco smoke and asbestos based on survey questions. METHODS Alpha-Tocopherol, Beta Carotene Cancer Prevention (ATBC) Study of 50-69-year-old Finnish male smokers enrolled 1985-1988. These analyses are based on the placebo group and the alpha-tocopherol supplementation group, altogether 14 011 men, with full information on tobacco smoking. Mortality follow-up was to the end of April 1993 and it was based on the complete death certificate register of the Statistics Finland. RESULTS Lung cancer mortality of basic-educated men was 32% (rate ratio [RR] = 1.32; 95% CI : 0.93-1.87) higher than that of better-educated men in the ATBC Study. The excess is practically unchanged when additional adjustment was made for age at initiation, duration of smoking, current smoking at baseline and at first follow-up, smoke inhalation, occupational exposure to asbestos and interactions between asbestos exposure and all smoking variables. This excess mortality was about 40% of the similar excess observed in the general population of men of similar age. CONCLUSIONS Educational differences in lung cancer mortality in the total Finnish population are likely to be mainly caused by differences in exposure, particularly to active smoking. Further understanding of the determinants and consequences of socioeconomic differences in smoking behaviour are of major scientific and public health importance.