Autoimmunity and cancer. A case presentation

Abstract

Autoimmune diseases are those where harmful immune responses for the body are triggered, due to a failure in tolerance that leads to the production of self-reactive lymphocytes able to recognize and respond to their own. In some autoimmune diseases, a higher risk of cancer mortality has been estimated compared to healthy individuals; however, for systemic lupus erythematosus, a low incidence rate has been reported for rectal localization. We present the case of a 41-year-old patient with clinical and serological diagnosis of lupus, 16 years of evolution, who presents rectorragia, anemia and abdominal pain. When performing the endoscopic examination, a tumor mass was found at the level of the rectum. Sample was taken for histological study which reported a moderately differentiated squamous cell carcinoma. There are several pathophysiological mechanisms potentially involved in tumorigenesis in a patient with autoimmune disease. The immune response to itself, expressed as hypersensitivity, leads to the underlying inflammatory process. Some specificities of autoantibodies, for their ability to interfere with intracellular signaling mechanisms, cell cycle control and apoptosis regulation, could also be involved, as has been reported for antiphospholipid and antiGRP78 antibodies. These or other factors may have contributed to the development of cancer in the patient with systemic lupus erythematosus.