Herbal therapy use by cancer patients: a literature review on case reports.

Complementary and alternative medicine use is common amongst cancer patients. In many surveys, herbal medicines are amongst the most commonly used group of treatments. Herbal remedies are believed by the general public to be safe, cause less side-effects and less likely to cause dependency. The authors performed a literature review to assess which herbal approaches have had associated cancer case reports and determine which of these have been studied in prospective research. Eighteen case reports of patients having apparent antitumour effects from herbal therapy and 21 case reports of toxic effects of herbs used by cancer patients were identified. Clinicaltrials.gov and MEDLINE (via PubMed) were searched for each of the herbal products identified in these reports. Clinical trials in cancer populations were identified for green tea extracts or compounds (n=34), phytoestrogens (n=27), mistletoe (n=8), Ganoderma lucidum (n=1), noni (n=1) and Silymarin (n=1). Daikenchuto, PC-SPES, Nyoshinsan/TJ and Saw palmetto have also been studied prospectively. In conclusion, some of the herbs with promising case report findings have undergone prospective clinical investigations but many others have either not yet been explored or the results have not been reported in English. Unconventional therapies, such as herbs and minerals, used in ancient medical traditions have led to the identification of active anticancer agents. Mechanisms to support prospective research with such approaches are discussed.