Researchers are to investigate whether a genistein-rich food, derived from soybeans and shiitake mushrooms, could help slow or even halt the progression of early prostate cancer. The new trial, to be carried out by a team at the University of California Davis Cancer Center, will test the action of genistein concentrated polysaccharide, or GCP, on men who are on active surveillance or ‘watchful waiting’ for prostate cancer. Watchful waiting is recommended for some prostate cancers that cause no symptoms, are expected to grow very slowly, and are small and contained within one area of the prostate. The new study builds on a preliminary trial, completed last year, that found GCP reduced levels of prostate-specific antigen (PSA) in a small group of ‘watchful waiting’ patients. Rising blood levels of PSA, a marker for prostate cancer, in men with diagnosed prostate cancer can be a signal of disease progression, while falling levels can signal remission. GCP is already used as a complementary therapy for prostate cancer in Japan, Korea and other parts of Asia.
