The comparative incidence of malignant disease in rheumatoid arthritics exposed to different treatment regimens.

Cytotoxic drugs are effective in disease suppression and affect the immune system. The correlation between these is poor, in many patients, at the dosage used in man. This may partly explain why the large increased risk of neoplasia, initially predicted, has not been shown to follow the use of cytotoxic therapy. The cause of death in patients with rheumatoid arthritis has been assessed both by surveys based on clinical populations and by reviews of necropsy records. There have been few attempts to assess the influence of drug therapy on mortality, or on the incidence of neoplasia. In addition, evidence is accumulating to suggest that lymphoreticular tumours may be associated with autoimmune disease. There have now been several long-term studies of patients with rheumatoid arthritis treated with immunosuppressives; azathioprine and cyclophosphamide in particular. These studies are reviewed and it is concluded that the incidence of most of the common cancers is not increased.