The Role of Interleukin-6 and Inflammatory Cytokines in Pancreatic Cancer-Associated Depression

Pancreatic cancer is historically known for representing a challenge for both diagnosis and treatment. Despite the advances in medicine, science, and technology, it remains the third leading cause of cancer-related deaths in the United States. The association between pancreatic cancer and major depression preceding the diagnosis is well known; however, it is still poorly understood, being considered an obscure piece of the puzzle the disease represents. It has been characterized as a paraneoplastic syndrome caused by the dysregulation of inflammatory cytokines, especially interleukin-6 (IL-6). Despite many types of studies describing the association, researchers have been reluctant to recommend it as a screening tool or early marker of the disease, mainly because of the non-specific nature of depression and anxiety in the studied patients. In this literature review, we aim to better understand the relationship between pancreatic cancer and major depression and characterize the immunologic mechanism of action behind the association.