ABSTRACT
Melatonin is a hormone produced mainly in the pineal gland. Plasma levels exhibit a circadian variation with the highest concentration occurring at night. The human biologic effects of melatonin depend upon the time of day it is made available. One of these effects is the setting and resetting of circadian clocks (chronobiotic effect). Additionally, it may be a potent antioxidant and immunomodulator and has been shown to have antitumor, anticytokine, anti-insomnia, and anticachexia effects. Melatonin has also been shown to improve survival and performance status in patients with advanced cancer. Objective tumor response occurs with melatonin alone or when combined with interleukin-2 (IL-2). Further, melatonin reduces radiation- and chemotherapeutic-induced toxicity. Symptomatic and circadian disruption is linked to increased cancer risk. The chronobiotic capacity of melatonin to reset circadian clocks may provide a verifiable strategy to reduce cancer risk and enhance quality of life by diminishing cancer-induced circadian disruption.
Subject(s)
Adjuvants, Immunologic/therapeutic use , Antioxidants/therapeutic use , Melatonin/therapeutic use , Neoplasms/drug therapy , Palliative Care/methods , Adjuvants, Immunologic/metabolism , Adjuvants, Immunologic/pharmacokinetics , Antioxidants/metabolism , Antioxidants/pharmacokinetics , Cachexia/drug therapy , Cachexia/etiology , Chronotherapy/methods , Depression/drug therapy , Depression/etiology , Drug Therapy, Combination , Humans , Hypotension/drug therapy , Hypotension/etiology , Interleukin-2/therapeutic use , Melatonin/metabolism , Melatonin/pharmacokinetics , Metabolic Clearance Rate , Neoplasms/complications , Neoplasms/mortality , Neoplasms/psychology , Quality of Life , Research Design , Sleep Initiation and Maintenance Disorders/drug therapy , Sleep Initiation and Maintenance Disorders/etiology , Survival Analysis , Thrombocytopenia/drug therapy , Thrombocytopenia/etiology , Treatment OutcomeABSTRACT
BACKGROUND: Shark cartilage has been a popular complementary or alternative medicine intervention. The basis for this popularity is the claim that sharks rarely get cancer because of the high proportion of cartilage in the shark's body. However, early studies were equivocal. Therefore, a clinical trial was conducted to look at the impact of shark cartilage in patients with advanced cancer. The primary goal of this trial was to determine whether a shark cartilage product improved overall survival for patients with advanced cancer who were getting standard care. Secondary research goals were to evaluate toxicities, tolerability, and quality of life associated with this shark cartilage product. METHODS: The study was a two-arm, randomized, placebo-controlled, double-blind, clinical trial. Patients with incurable breast or colorectal carcinoma had to have good performance status and organ function. Patients could be receiving chemotherapy. Patients were all to receive standard care and then to be randomly selected to receive either a shark cartilage product or an identical-appearing and smelling placebo 3 to 4 times each day. RESULTS: Data on a total of 83 evaluable patients were analyzed. There was no difference in overall survival between patients receiving standard care plus a shark cartilage product versus standard care plus placebo. Likewise, there was no suggestion of improvement in quality of life for patients receiving the shark cartilage, compared with those receiving placebo. CONCLUSION: This trial was unable to demonstrate any suggestion of efficacy for this shark cartilage product in patients with advanced cancer.