With Comments from Russell H. Greenfield, MD
Green Tea and Prostate Cancer
Source: Jatoi A, et al. A phase II trial of green tea in the treatment of patients with androgen independent metastatic prostate carcinoma. Cancer 2003;97:1442-1446.
Goal: To evaluate the antineoplastic effects of green tea in men with androgen independent metastatic prostate cancer.
Design: Phase II multi-institutional interventional trial.
Subjects: Fifty-four asymptomatic patients with progressively increasing PSA levels despite hormone therapy (42 ultimately deemed evaluable).
Methods: Participants were instructed to mix 1 g of tea into warm or cold water six times daily (total daily dose = 6 g). The men met with their physicians monthly for 6 months and PSA levels were determined at each visit. Objective response to green tea was defined as a > 50% drop in PSA level on consecutive determinations at least 4 weeks apart.
Results: A 43% increase in PSA levels was the median change noted at the end of the first month. Only one patient exhibited a decline in PSA level of 50% compared with baseline, but the response was not sustained. There were no non-biochemical tumor responses (based on physical exam and radiographic assessment).
Conclusion: Green tea does not offer antineoplastic benefit to men with androgen independent metastatic prostate cancer as defined by PSA levels.
Study strengths: Statistical analysis; patient follow-up; compliance with regimen (self-reported).
Study weaknesses: All green teas are not equipotent with regard to levels of epigallocatechin-3-gallate (EGCG); EGCG content of this tea was not noted. Also, median time of participation in the trial was only one month.
Of note: A significant number of adverse side effects were reported, including insomnia, abdominal pain, and confusion; the only other treatment permitted during the trial was the use of LHRH agonists.
Did you know? EGCG is the polyphenol to which most of green tea’s anticancer effects have been ascribed. In large studies of relatively healthy people, green tea has demonstrated antitumor activity.
Clinical import: This trial of green tea does not support its use for men with androgen independent metastatic prostate cancer in the short term. However, results of the study should not be extrapolated to imply that green tea containing adequate polyphenols offers no benefit with respect to preventing prostate cancer or in the treatment of less aggressive disease.
What to do with this article: Keep a hard copy in your file.
Dr. Greenfield is Medical Director, Carolinas Integrative Health, Carolinas HealthCare System, Charlotte, NC.