spore (GLS), an over-the-counter herbal supplement, is widely used by cancer patients in China. Although preclinical studies have shown it to be safe, complete safety data on GLS is still lacking. In this article, we report 5 cases of gastrointestinal cancer that were treated with GLS plus multiple strategies between 2010 and 2011. These patients presented with increased levels of the serum tumor marker CA72-4, one of the most valuable markers for monitoring therapeutic response in patients receiving gastrointestinal cancer treatment, after oral ingestion of GLS twice a day for 1 or 2 months. Interestingly, CA72-4 rapidly returned to normal levels when the patients discontinued the supplement and no change in clinical symptoms accompanied the CA72-4 surge. Taking into consideration that the underlying mechanism of this reaction is obscure, we suggest that additional studies are urgently needed and GLS be used with caution in cancer patients.
Keywords: CA72-4; Ganoderma lucidum spore; alternative medicine; case report; gastrointestinal cancer.