Cancer-related fatigue, inflammation and thyrotropin-releasing hormone.

Aging and aging related illnesses such as cancer have been associated with inflammatory changes. Cancer-related behavioral comorbidities such as fatigue, sleep disturbances, depression have also been associated with inflammation, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and other neuroendocrine changes. From a clinical perspective, cancer-related fatigue demonstrates striking similarities with the cytokine-induced sickness phenomenon in animal models. Thyrotopin-releasing hormone (TRH) plays a homeostatic role in its interaction with several biological systems, including a critical role in its interactions with the immune system. Considerable evidence supports a pivotal role for TRH in the inflammatory processes with specific relevance to the "cytokine-induced sickness behavior" paradigm. Additionally, TRH exerts arousing and analeptic effects in instances of behavioral depression. In a small proof-of-concept study conducted by our group, we investigated TRH administration as a treatment fatigue in cancer survivors in comparison with saline administration using a double-blind, crossover design. We also evaluated impact of TRH/saline administration on the inflammatory markers in these patients. TRH administration was associated with significant improvement (p < 0.05) in fatigue levels as measured by the Visual Analog Scale-Energy (VAS-E), was associated with significant (p < 0.05) improvement in sleep disturbances and improved quality of life. Notably, TRH administration was associated with decrease in C-reactive protein (CRP) levels, a marker of inflammation. This decrease in CRP level with TRH administration was associated with improvement in energy levels as measured by the VAS-E. The present review supports potential utility of TRH-based therapeutics in medical and psychiatric disorders with underlying inflammatory processes.