Cachexia is a prevalent multifactorial syndrome characterized by a substantial decrease in food intake, which results from processes such as proteolysis, lipolysis, inflammatory activation, and autophagy, ultimately leading to weight loss. In cancer patients, this condition is referred to as cancer-related cachexia (CRC) and affects over 50% of this population. A comprehensive understanding of the intricate interactions between tumors and the host organism is essential for the development of effective treatments for tumor cachexia. This review aims to elucidate the role of the tumor microenvironment (TME) in the pathogenesis of tumor-associated cachexia and to summarize the current evidence supporting treatment modalities that target the TME.