Healthnotes Newswire (November 9, 2000)—The herbal formula PC-SPES has pronounced anticancer activity, according to a new report in the Journal of Clinical Oncology.¹ This study provides the best evidence yet that PC-SPES can help men with prostate cancer that worsens despite previous surgical, radiation, drug, or hormone therapy. However, most participants in this trial also experienced significant side effects caused by these herbs.

Seventy men with prostate cancer were studied, including patients with cancer affected by testosterone (androgen-dependent cancer) and those with cancer not affected by testosterone (androgen-independent cancer). Men with androgen-dependent prostate cancer often have less advanced disease and also have a better overall chance of survival compared to men with androgen-independent cancer. Each man was given one capsule containing 320 mg of PC-SPES three times per day for a week, then two capsules three times per day for a week, and finally three capsules three times per day for the remainder of the trial, unless side effects required lower amounts.

All patients with androgen-dependent prostate cancer that could be evaluated had a large decline (80% or greater) in prostate-specific antigen (PSA) levels. PSA is a blood marker for evaluating prostate cancer, with lower numbers generally correlating with improvement. In 26 of these patients, PSA could no longer be detected. After 64 weeks, disease had progressed in only one of the men with androgen-dependent cancer. In this group, both of the two men with cancer that had spread to bone showed evidence of improvement. In one of these two men, cancer in bone disappeared while taking PC-SPES. In another patient, cancer that had spread to the bladder disappeared as a result of PC-SPES therapy.

Just over half of the androgen-independent group had declines in PSA levels of more than 50%. After an average of 16 weeks, however, PSA scores began to increase again in this group of patients. Within this group, only two of 25 men with cancer that had spread to bone showed evidence of significant improvement. Of the 35 androgen-independent patients, 30 eventually stopped taking PC-SPES because of side effects or progression of the cancer.

Virtually every man suffered side effects, particularly loss of libido, impotence, breast tenderness and/or enlargement, and hot flashes, although some men in the androgen-independent group showed improvement of pre-existing hot flashes that had been caused by conventional treatment. Life-threatening side effects included three cases of pulmonary embolism (blood clots that form in the legs and travel to the lungs causing blockage of blood flow) and one case of kidney failure.

PC-SPES has been repeatedly shown in prior clinical trials^{2 3 4 5} to be beneficial in men with prostate cancer. Most of the data indicate that PC-SPES works similarly to estrogen, which has anticancer effects in men with prostate cancer. However, its exact mechanism of action has not been fully determined. PC-SPES increases the risk of formation of blood clots. To prevent this side effect, most physicians who prescribe PC-SPES also prescribe warfarin (Coumadin^®) or heparin at the same time. PC-SPES should only be used under the careful supervision of a physician.

PC-SPES contains extracts of the Chinese herbs Glycyrrhiza glabra (licorice) and Glycyrrhiza uralensis (gan cao), Isatis indigotica (isatis), Panax pseudoginseng (tienchi ginseng), Ganoderma lucidum (reishi mushroom), Scutellaria baicalensis (Asian skullcap), Denodrantherma morifolium, and Rabdosia rubescens, as well as the American herb Serenoa repens (saw palmetto). The name of this formulation is derived from an abbreviation for prostate cancer (PC) and the Latin word for hope (spes).