Incidence of Cancer among Men with the Felty Syndrome

OBJECTIVE: To estimate the incidence of cancer (especially lymphoproliferative malignancies) in patients with the Felty syndrome. DESIGN: A retrospective cohort study. SETTING: A computerized database of all discharge records for 1969 to 1990 from a Veterans Affairs hospital. PATIENTS: 906 men with a discharge diagnosis of the Felty syndrome. MEASUREMENTS: Standardized incidence ratios (SIR) (ratios of observed-to-expected events) estimated the risk for specific cancers. Hospital records confirmed the diagnoses of the Felty syndrome and cancer. RESULTS: We observed a twofold increase in total cancer incidence (137 patients; SIR = 2.09; 95% CI, 1.8 to 2.5). The risk for non-Hodgkin lymphoma (19 patients; SIR = 12.8, CI, 7.7 to 20.0) was much greater than the twofold increase in risk for lymphoma generally reported for rheumatoid arthritis. The risk for leukemia was increased but only within 5 years of the first hospitalization for the Felty syndrome, (13 patients; SIR = 7.67; CI, 4.1 to 13.1). CONCLUSION: The increased risk for non-Hodgkin lymphoma after the Felty syndrome in our study is similar to the risk associated with the Sjögren syndrome and may reflect similar immunostimulatory mechanisms.