Commentary: the pharmacological antioxidant amifostine -- implications of recent research for integrative cancer care.
Amifostine is a pharmacological antioxidant used as a cytoprotectant in cancer chemotherapy and radiotherapy. It is thought to protect normal tissues relative to tumor tissue against oxidative damage inflicted by cancer therapies by becoming concentrated at higher levels in normal tissues. The degree to which amifostine nevertheless accumulates in tumors and protects them against cancer therapies has been debated. Guidelines have been published that direct its use in chemotherapy and radiation, taking into consideration the concerns of tumor protection. In this article, clinical studies of amifostine appearing since the publication of the most recent set of guidelines are reviewed. Randomized and nonrandomized trials of regimens involving chemo-therapeutic agents (chemotherapy, chemoradiation, conditioning regimens for bone marrow transplant) are discussed. Nineteen studies showed positive effects for amifostine reducing the level of side effects of these regimens, while 9 showed no effect and 1 had a questionable result. Clinically relevant levels of amifostine toxicity were observed in several studies, but subcutaneous administration may reduce such toxicity. Amifostine showed protection against mucositis, esophagitis, neuropathy, and other side effects, although protection against cisplatin-induced ototoxicity was not observed. No evidence of tumor protection was observed. Amifostine may enable populations unable to tolerate conventional cancer therapy to receive treatment of their cancers, even if some degree of tumor protection is eventually discovered. The authors discuss the implications of this research for patient populations seen in integrative cancer care centers and for research on phytochemical antioxidants such as vitamins and carotenoids.
Block
Keith I
KI
Block Center for Integrative Cancer Care, Evanston, Illinois 60201, USA. drblock@blockmedical.com
Gyllenhaal
Charlotte
C
D004999:Amifostine / Q000009:adverse effects / Q000627:therapeutic use*; D000975:Antioxidants / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D003131:Combined Modality Therapy; D064420:Drug-Related Side Effects and Adverse Reactions / Q000139:chemically induced / Q000209:etiology; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy / Q000628:therapy*; D018384:Oxidative Stress / Q000187:drug effects; D017410:Practice Guidelines as Topic
D000975:Antioxidants; D004999:Amifostine