Autoimmunity and cancer.

The association between autoimmune diseases and cancer is to be considered one of the most well established and clinically challenging issues. Several mechanisms are shared in the pathogenesis of both autoimmune diseases and cancer, they are thus direct candidates as causative factors, but direct proof is lacking, as in the case of serum autoantibodies. Furthermore, accurate estimates of the risk of cancer in patients with newly diagnosed or long-standing autoimmune disease remain to be reported. The role of awareness bias and diagnosis latency, as well as of serum autoantibodies, epigenetics and genomic susceptibility, cannot be overlooked in this scenario. Finally, an indirect proof of associations is provided by the common autoimmune phenomena presenting as paraneoplastic. The present article will critically review the available evidence on the common mechanisms and epidemiology underlying the risk of cancer in patients with autoimmune disease.