Ganoderma lucidum (Reishi mushroom) for cancer treatment(Review)
Ganoderma lucidum is a natural medicine that is widely used and recommended by Asian physicians and naturopaths for its supportingeffe cts on immune system. Laborator y research and a handful of preclinical trials have suggested that Ganoderma lucidum carries promisinganticancer and immunomodulatory properties. The popularity of taking G. lucidum as an alternative medicine has been increasing incancer patients. However, there is no systematic review that has been conducted to evaluate th e actual benefits of Ganoderma lucidum in cancertreatment.
To evaluate the clinical effects of G. lucidum on long-term sur vival, tumour response, host immune functions and quality of life incancer patients, as well as adverse events associated with its use.
We searched an extensive set of databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EM-BASE, NIH, AMED, CBM, CNKI, CMCC and VIP Information/Chinese Scientific Journals Database was search ed f or randomisedcontrolle d trials (RCTs) in October 2011. Other strategies used were scanning the references of articles retrieved, handsearching of the International Journal of Medicinal Mushrooms and contact with herbal medicine experts and manufacturers of Ganoderma lucidum. For thisupdate we updated the searches in February 2016.
To be eligible for being included in this review, studies had to be RCTs comparing the ef ficacy of Ganoderma lucidum medications to active orplacebo control in patients with cancer that had been diagnosed by pathology. All types and stages of cancer were eligible for inclusion. Trials were not restricted on the basis of language.
Data collection and analysis
Five RCTs met the inclusion criteria and were included in this review. Two independent review authors assessed the methodologicalquality of individual trials. Common primar y outcomes were tumour response evaluated according to the World Health Organization(WHO) criteria, immune function parameters such as natural killer (NK)-cell activity and T-lymphocyte co-receptor subsets, andquality of life measured by the Karnofsky scale score. No trial had recorded long-term sur vival rates. Associated adverse events wererepor ted in one study. A meta-analysis was performed to pool available data fr om the primary trials. Results were gauged using relative risks (RR) and standard mean differences (SMD) for dichotomous and continuous data respectively, with a 95% confidence interval(CI).
The methodological quality of primary studies was generally unsatisfying and the results were reported inadequately in many aspects.Additional information was not available from primary trialists. The meta-analysis results showed that patients who had been given G.lucidum alongside with chemo/radiotherapy were more likely to respond positively compared to chemo/radiotherapy al one (RR 1.50;95% CI 0.90 to 2.51, P = 0.02). G. lucidum treatment alone did not demonstrate th e same regression rate as that seen in combinedtherapy. The results for host immune function indicators suggested that G. lucidum simultaneously increases the percentage of CD3,CD4 and CD8 by 3.91% (95% CI 1.92% to 5.90%, P < 0.01), 3.05% (95% CI 1.00% to 5.11%, P < 0.01) and 2.02% (95% CI0.21% to 3.84%, P = 0.03), respectively. In addition, leukocyte, NK-cell activity and CD4/CD8 ratio were marginally elevated. Fourstudies showed that patients in the G. lucidum group had relatively improved quality of life in comparison to controls. One studyrecorded minimal side effects, including nausea and insomnia. No significant haematological or hepatological toxicity was reported.
Our review did not find sufficient evidence to justify the use of Ganoderma lucidum as a first-line treatment for cancer. It remains uncertainwhether Ganoderma lucidum helps prolong long-term cancer survival. However, Ganoderma lucidum could be administered as an alternative adjunct toconventional treatment in consideration of its potential of e nhancing tumour response and stimulating host immunity. Ganoderma lucidum was generally well tolerated by most participants with only a scattered number of minor adverse events. No major toxicity was obser vedacross the studies. Although th ere were few reports of harmful effect of G. lucidum, the use of its extract should be judicious, especiallyafter thorough consideration of cost-benefit and patient preference. Future studies should put e mphasis on the improvement inmethodological quality and further clinical research on the effect of G. lucidum on cancer long-term survival are nee ded. An update tothis review will be per formed every two years.