Rheumatic diseases and malignancy--is there an association?

An association between rheumatic diseases and malignancy has been claimed in a variety of settings. This editorial reviews published data addressing the overall risk of malignancy, and of particular types of cancer, in the context of various autoimmune rheumatic diseases. For patients with Sjögren's syndrome, systemic sclerosis with pulmonary fibrosis, or with dermatomyositis/polymyositis there is a documented association with an increased risk of malignant disease. Patients with rheumatoid arthritis may also have an increased risk of cancer. It is still controversial whether systemic lupus erythematosus is associated with an increased risk of developing malignancy. More epidemiologic studies are needed to try and clarify many of these associations, in particular the potential risks associated with cytotoxic therapy.