A Phase II trial of a combination herbal supplement for men with biochemically recurrent prostate cancer.

Abstract

BackgroundMen with biochemical recurrence (BCR) of prostate cancer are typically observed or treated with androgen deprivation therapy. Non-hormonal, non-toxic treatments to slow the rise of PSA are desirable. We studied a combination herbal supplement, Prostate Health Cocktail (PHC), in prostate cancer cell lines and in a population of men with BCR.MethodsPC3, LAPC3, and LNCaP cells were incubated with increasing concentrations of PHC suspension. Men previously treated for prostate cancer with surgery, radiation, or both with rising PSA but no radiographic metastases were treated with 3 capsules of PHC daily; the primary endpoint was 50% PSA decline. Circulating tumor cells (CTCs) were identified using parylene membrane filters.ResultsPHC showed a strong dose-dependent anti-proliferative effect in androgen-sensitive and independent cell lines in vitro and suppression of androgen receptor expression. 40 eligible patients were enrolled in the clinical trial. Median baseline PSA was 2.8 ng/mL (1.1-84.1) and 15 men (38%) had a PSA decline on study (1%-55% reduction) ; 25 (62%) had rising PSA on study. The median duration of PSA stability was 6.4 months. Two patients had grade 2/3 transaminitis; the only other grade 2 toxicities were hyperglycemia, hypercalcemia and flatulence. There were no significant changes in testosterone or dihydrotestosterone. CTCs were identified in 19 men (47%).ConclusionAlthough the primary endpoint was not met, Prostate Health Cocktail was well tolerated and was associated with PSA declines and stabilization in a significant number of patients. This is the first report of detecting CTCs in men with BCR prostate cancer. Randomized studies are needed to better define the effect of PHC in men with BCR.