Cancer and Autoimmune Diseases

Purpose of review: The association between autoimmunity and cancer is well established. Cancer has been implicated in some autoimmune disorders (AID), such as scleroderma and myositis. On the other hand, many AID and immunosuppressive therapy have been linked to an increased risk for cancer. We reviewed the accumulating data on the association between autoimmunity and cancer during the past 3. years, with an emphasis on large cohorts, as well as concept changing discoveries in the association of cancer and autoimmunity.Recent findings: Recent published data from large registries and databases have changed our perspective on the association of AID and cancer, as well as the presumed association between anti-tumor necrosis factor therapy and certain malignancies, suggesting a small to no increase in almost all types of cancers. Similarly, the increased risk of malignancies in some AID, such as Sjogren's syndrome (SS) and lupus, may be different from previous estimations. New associations with malignancies were discovered, such as IgG4-related disease, Behcet's, and sarcoidosis, which were not clearly associated with cancer in the past.These newly described associations may have clinical implications and contribute to our understanding of both autoimmunity and cancer.Similarly, we reviewed studies of autoimmunity secondary to malignancy and the concomitant appearance of cancer with autoimmune disease, such as the discovery of a specific mutation in scleroderma (SS) patients who developed cancer, which establishes the association between these disorders and sheds light on the pathology behind this association.