Malignant neoplasms in autoimmune rheumatic diseases - Examination of the risk of developing a malignancy among five different rheumatic diseased in one institution

Relationships between autoimmune rheumatic diseases nad malignant neoplasms have been discussed, but there is no study of the different rheumatic dise ases examining the risk of developing cancer. Our study has examined probab ilities for developing malignancy among patients with connective tissue dis eases seen in single institution. Patients with autoimmune rheumatic diseas e and malignancy were compared with patients with the same autoimmune rheum atic diseases without malignancy. All case identified through record-linkag e from 1964 to 1996 were selected. Four controls per case were randomly sel ected from a pool of 3228 patients. The rheumatic disease considered were r heumatoid arthritis (RA), systemic lupus erythematosus (SLE), primary Sjogr en's syndrome (pSS), dermatomyositis-polymyositis (DM-PM), and systemic scl erosis (Scl). The statistical analysis was conducted by conditional logisti c regression, testing rheumatic disease as main effect. We identified 72 ca ses and 288 controls. Fifty-three of the cases had solid tumors, and 19 had lymphoproliferative neoplasms. The risk of developing a malignancy was con siderably higher in DM-PM than in SLE (odds ratio [OR] = 17.5, 95% confiden ce interval [CI] 4.1-75.7), in pSS than in SLE (OR = 5.7, 95% CI2.2-`5.1), and in Scl than in SLE (OR = 5.4, 95% CI 1.6-18.0). These risks persisted a fter controlling for rheumatic disease duration, the time the disease was a ctive, and anti-rheumatic treatment. RA had an OR of 1.8 (95% CI 0.9-3.4) w ith respect to SLE. This is the first study which describes the magnitude of risks among rheuma tic diseases associated with the probability of developing a malignant neop lasm whether lymphoproliferative or solid. The risks in this series depend on the primary rheumatic disease, with DM-PM, pSS, and Scl all having great er risk than SLE.