Cancer-triggered systemic disease and therapeutic targets.

Cancer provokes systemic diseases through three possible mechanisms: 1) Distal metastasis in multiple tissues and organs, which directly causes functional damage and impairment of involved organs; 2) Paraneoplastic syndrome (PNS) that affects multiple organ systems, including the endocrine, gastrointestinal, hematologic, neurologic, dermatologic, and ophthalmologic systems; and 3) Cancer cachexia (CCA) or self-wasting syndrome characterized by anorexia, progressive bodyweight loss, adipose atrophy, and muscle atrophy. While cancer metastasis has received considerable attention for comprehensive research, PNS and CCA remain relatively overlooked. At the time of this writing, effective treatments of PNS and CCA in human cancer patients are lacking. This review focuses on discussing mechanistic insights into PNA and CCA and current advances in development of new possible therapeutic interventions.