A cohort study of cancer among sarcoidosis patients.

Sarcoidosis is a chronic inflammatory condition that may increase the risk of cancer, but limited information is available on occurrence of cancer in these patients. We compared the incidence of cancer among 2,013 White and 3,755 Black male patients admitted to Veterans hospitals in the United States during 1969-1996 with a diagnosis of sarcoidosis, with that of 2,792,503 White and 662,204 Black nonsarcoidosis patients admitted to the same hospitals. Patients suffering from pulmonary and autoimmune diseases were excluded from the study, as was the first year of follow-up after first admission for sarcoidosis. A total of 241 malignant neoplasms were diagnosed in sarcoidosis patients [relative risk 0.99, 95% confidence interval (CI) 0.87-1.13]. The risks of rectal cancer (relative risk 2.12; 95% CI 1.27-3.52), colon cancer (relative risk 1.55; 95% CI 0.99-2.43) and kidney cancer (relative risk 1.84; 95% CI 1.02-3.33) were increased in sarcoidosis patients when compared with other Veterans hospital patients, whereas the risk of lung cancer was decreased (relative risk 0.60; 95% CI 0.42-0.85). The risk of kidney cancer remained elevated 10 years after first admission. Results were generally consistent among ethnic groups, although the increased risk of colon and kidney cancer was observed only in White patients. These results provide further evidence for an increased risk of specific cancers in patients with sarcoidosis, but do not support any additional increase in overall cancer risk.