Cancer incidence in a cohort of Finnish male smokers.

A total of 29,133 male smokers, aged 50-69 years, were recruited into the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in 1984-1988. The nationwide Finnish Cancer Registry (FCR) recorded 5944 incident cases of cancer in this cohort through the end of 1999. Compared with the FCR data of the entire Finnish male population of same age the standardized incidence ratio (SIR) of total cancer in the ATBC cohort was 1.55 [95% confidence interval (CI) 1.51-1.59]. There was a significant excess of established smoking-related malignancies, such as lung cancer (SIR 2.45, 95% CI 2.35-2.56), and cancers of the tongue, mouth, pharynx, larynx, oesophagus, pancreas, stomach, liver, urinary bladder and kidney. In addition to these sites, cancers of the prostate and colon were slightly more common in the ATBC cohort than in the total Finnish male population (SIR 1.10, 95% CI 1.04-1.18 and SIR 1.14, 95% CI 1.00-1.30, respectively). In conclusion, the risk of many cancers was significantly higher in the ATBC Study cohort compared with the total Finnish male population of same age. In addition to the well known smoking-related cancers, cigarette smoking may increase slightly the risk of colon and prostate cancer, too.