Autoimmunity and cancer

In many autoimmune rheumatic diseases, there is an increased risk of cancer compared to the general population. The link between autoimmunity and cancer is dynamic and bidirectional. Recent advances in terms of knowledge of biology, epidemiology, and long-term outcomes for the autoimmune rheumatic diseases have revealed several new connections between these two entities. Data suggest that chronic inflammation from the rheumatic diseases or their therapies may contribute to the onset and promotion of cancer. Conversely, antitumor immune responses may become cross-reactive with self-tissues resulting in the development of autoimmunity. In this review, we discuss about the potential mechanisms that link autoimmune rheumatic diseases and cancer and the association of malignancies with common autoimmune disorders. The increased incidence of malignancy in autoimmune rheumatic diseases has been largely described, although the biology underpinning this relationship should be further investigated. The development of evidence-based cancer screening recommendations in patients with autoimmune rheumatic diseases is complex due to the heterogeneity of clinical rheumatic phenotypes, cancer sites at risk and exposure to anti-neoplastic and anti-rheumatic treatment. In order to lay the foundation of risk stratification and targeted cancer screening, larger longitudinal cohort studies that provide a more detailed framework of the links between cancer and autoimmunity are urgently needed.