CANCER RISK AND MORTALITY PATTERNS AMONG SILICOTIC MEN IN SWEDEN AND DENMARK

Data from nation-wide registry-based cohorts of patients hospitalized for silicosis in Sweden from 1965 to 1983 and Denmark from 1977 to 198 9 were linked to national cancer registries in both countries and to m ortality data in Sweden to evaluate the risk of cancer and other disor ders among hospitalized silicotic patients. The overall cancer standar dized incidence ratio (SIR) was 1.5 (95% confidence interval [CI], 1.3 to 1.7) in Sweden and 1.7 (95 % CI; 1.2 to 2.3) in Denmark, primarily because of elevations in primary lung cancer in both Sweden (SIR, 3.1 ; CI, 2.1 to 4.2) and Denmark (SIR, 2.9; CI; 1.5 to 5.2), For Sweden, the all-causes standardized mortality ratio (SMR) was 2.0 (1.9 to 2.2) . The SMR for all malignancies was 1.5 (1.2 to 1.7), primarily because of excesses of lung cancer (SMR, 2.9 CI, 2.1 to 3.9). The significant increase in mortality for all infectious and parasitic conditions (SM R, 11.2) was primarily due to tuberculosis (SMR, 21.8). Significant ex cesses in mortality from silicosis (SMR, 523), bronchitis (SMR, 2.6) a nd emphysema (SMR, 6.7) contributed to the elevation in nonmalignant r espiratory deaths (SMR, 8.8), whereas excess mortality from musculoske letal disorders (SMR, 5.9) was due to six deaths from autoimmune disea ses. Despite limitations of the available data our findings are consis tent with previous reports indicating that silicotic patients are at e levated risk of lung cancer, nonmalignant respiratory diseases, tuberc ulosis, and certain autoimmune disorders.