Researchers have long noted links between cancer and autoimmune rheumatic diseases. Both naturally occurring or pharmacologically induced anti-tumor immune responses may lead to autoimmune diseases.
Across the broad spectrum of autoimmune diseases, a marked risk elevation of cancer is seen in patients with myositis and scleroderma. “Data from scleroderma and myositis illustrate that natural occurring antitumor immune responses may lead to autoimmunity”, said Prof. Ami Shah, Director of Clinical and Translational Research at the Johns Hopkins Scleroderma Center, Baltimore (MD/USA).
In scleroderma as well as in myositis there is a striking temporal relationship between cancer and rheumatic disease onset. Recent data suggest a paraneoplastic mechanism of scleroderma pathogenesis in patients with scleroderma and RNA polymerase III autoantibodies. “These patients really show us the link between cancer and autoimmunity”, said Prof. Shah. “In our cohort, scleroderma patients with such autoantibodies have more than fivefold risk to develop cancer within two years of scleroderma onset”, said Prof. Shah.
These data strongly suggest that scleroderma is a by-product of an antitumor immune response for some patients. One question is whether new agents that are designed to trigger robust anti-tumor immune responses in oncology, such as checkpoint inhibitors can also lead to rheumatic disease through similar mechanisms. “At least some of our autoimmune disease could be triggered by underlying cancers and the immune responses that develop in response to cancer”, says Prof. Shah.
Therefore, careful cancer screening may be appropriate, at least for some patients with rheumatic disease. However, there are no evidence-based data to support that early diagnosis improves the outcome in these patients.
Shah A, Session “Autoimmunity and Cancer”, 2017 ACR/ARHP Annual Meeting, November 3-8 2017, San Diego (CA/USA).