RISK OF MALIGNANCY IN WOMEN WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective, To estimate the risk of malignancy in a cohort of patients with systemic lupus erythematosus (SLE) from a university medical cent er. Methods. The cohort consisted of patients with lupus who were resi dents of Allegheny County and who were seen at the University of Pitts burgh, 1981-91. Cases of cancer were identified by a postal survey and review of medical records. The expected number of malignancies in the lupus cohort were estimated from age, sex, and race adjusted census a nd cancer incidence data from Allegheny County. Standardized incidence ratios and 95% confidence intervals for all cancers were calculated. Results. Six (2.7%) malignancies were observed in the 219 lupus patien ts from Allegheny County during the observation interval (1981-91) and after the first visit at the University of Pittsburgh. The expected n umber of malignancies was 4.42. The standardized incidence ratio for c ancer in the lupus cohort from Allegheny County was 1.36 (95% confiden ce interval 0.50-2.96). The frequency of malignancy was not increased in the small number of patients who had received immunosuppressive dru gs before the diagnosis of cancer. Non-Hodgkin's lymphoma occurred in one patient, who also had Sjogren's syndrome, and in one patient befor e entry into this study who was treated with FK-506 following renal tr ansplant. No bladder cancers were observed during the study interval. Conclusion. The overall frequency of malignancy was not increased in t his medical center cohort of patients with lupus during a mean followu p interval of 5.2 yrs. Longterm followup and a multicenter effort is n eeded to refine risk estimates of cancer in patients with lupus.