Prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer.
OBJECTIVE
PC-SPES is an herbal supplement for which there are anecdotal reports of anti-prostate cancer activity. This phase II study was undertaken to assess the efficacy and toxicity of PC-SPES in prostate cancer patients.


METHODS
Thirty-three patients with androgen-dependent prostate cancer (ADPCa) and 37 patients with androgen-independent prostate cancer (AIPCa) were treated with PC-SPES at a dose of nine capsules daily. Clinical outcome was assessed with serial serum prostate-specific androgen (PSA) level measurement and imaging studies.


RESULTS
One hundred percent of ADPCa patients experienced a PSA decline of >/= 80%, with a median duration of 57+ weeks. No patient has developed PSA progression. Thirty-one patients (97%) had declines of testosterone to the anorchid range. Two ADPCa patients had positive bone scans; both improved. One patient with a bladder mass measurable on computed tomography scan experienced disappearance of this mass. Nineteen (54%) of 35 AIPCa patients had a PSA decline of >/= 50%, including eight (50%) of 16 patients who had received prior ketoconazole therapy. Median time to PSA progression was 16 weeks (range, 2 to 69+ weeks). Of 25 patients with positive bone scans, two had improvement, seven had stable disease, 11 had progressive disease, and five did not have a repeat bone scan because of PSA progression. Severe toxicities included thromboembolic events (n = 3) and allergic reactions (n = 3). Other frequent toxicities included gynecomastia/gynecodynia, leg cramps, and grade 1 or 2 diarrhea.


CONCLUSIONS
PC-SPES seems to have activity in the treatment of both ADPCa and AIPCa and has acceptable toxicity. Further study is required to determine whether its effects exceed those expected with estrogen therapy.
Small
E J
EJ
University of California at San Francisco, San Francisco, CA, USA. smalle@medicine.ucsf.edu
Frohlich
M W
MW
Bok
R
R
Shinohara
K
K
Grossfeld
G
G
Rozenblat
Z
Z
Kelly
W K
WK
Corry
M
M
Reese
D M
DM
D000230:Adenocarcinoma / Q000097:blood / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000728:Androgens / Q000502:physiology; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects / Q000627:therapeutic use*; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000097:blood / Q000188:drug therapy; D010936:Plant Extracts / Q000009:adverse effects / Q000627:therapeutic use*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy*; D013739:Testosterone / Q000097:blood
D000728:Androgens; D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; C114209:herbal preparation PC-SPES; D013739:Testosterone; D017430:Prostate-Specific Antigen