Prostate Cancer Prevention Trial With Quercetin and Genistein

Clinical Trial on the Effectiveness of the Flavonoids Genistein and Quercetin in Men With Rising Prostate-specific Antigen

The aim of the randomized controlled double-blind crossover trial is to evaluate the effectiveness of two dietary supplements containing polyphenolic phytochemicals (isoflavonoid genistein and flavonoid quercetin) in comparison with placebo on the rate of increase in prostate-specific antigen (PSA). In addition, secondary objective is to evaluate the incidence of prostate cancer and to analyze malondialdehyde and protein carbonyle as indicators of the oxidative status.

Prostate cancer (PC) is the most frequently occurring cancer in men. Its clinical incidence and mortality rates vary geographically, being much lower in Asia than in Western countries. Notably, latent PCs seem to be equally distributed, thus supporting the hypothesis, that environmental factors may be important in prostate cancer progression. Moreover, epidemiological evidence strongly supports the concept that the incidence of clinical prostate cancer depends on lifestyle factors, mainly related to diet. The isoflavone genistein and the flavonoid quercetin have been identified as likely preventive candidates. The aim of the intended clinical trial is to evaluate the hypothesized effectiveness of polyphenolic phytochemicals with highly purified dietary supplements in patients at high risk of clinical PC and without systemic treatment. This will provide data, which serve as an important pre-requesite for targeted dietary interventions using alternative medicine as preventive measures in men with latent PC.

Inclusion Criteria:

• Patients with deviant PSA constellation:

  1. Patients with PSA 2,5 - 4 μg/l and free PSA/total PSA < 15 %

  2. Patients with PSA > 4 μg/l with negative punch biopsy of the prostate

     Exclusion Criteria:

• chronic liver diseases, impaired kidney function

• inflammatory diseases of the urogenital tract

• history of malignancy of any organ system, treated or untreated, within the past three years whether or not there is evidence of local recurrence or metastases

• therapy with Doxazosin, Dutaserid and/ or Finasterid, Testosteron and other hormonal active medicaments

• inflammatory bowel diseases

• malabsorption/-digestion

• hypersensitivity/allergy to soy

• phytotherapy or intake of dietary supplements

• smoker

• abnormal clinical laboratory values at baseline

• participation in any other trial with an investigational new drug

• inability to sign informed consent