Crossroads between autoimmunity and cancer: underlying mechanisms and clinical implications

Autoimmune diseases arise from an aberrant immune response against self-antigens, whereas cancer often develops when the immune system fails to effectively detect and destroy malignant cells. Although historically viewed as distinct entities with opposing immune mechanisms, recent findings highlight significant overlaps in their immunological pathways. This review explores the intricate interplay between autoimmunity and cancer, focusing on immune surveillance, checkpoint regulation, cytokine signaling, and genetic susceptibility. In addition, we discuss epidemiological links, including the heightened risk of malignancy in patients with autoimmune disorders and the autoimmune manifestations often triggered by cancer immunotherapies. We place particular emphasis on shared molecular signatures, predictive biomarkers, and the bidirectional immune modulation that arises from checkpoint inhibitors and biologic agents. Finally, we address the major clinical challenges in managing patients who present with both conditions and propose future research directions aimed at refining immunotherapeutic strategies.