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Completed

NCT Number: NCT00255125

Role of Soy Supplementation in Prostate Cancer Development

This is a randomized study evaluating the effectiveness and direct effect a commercial soy supplement has on prostate cancer and normal prostate tissue. Patient will be randomized it either receive placebo or a commercial soy supplement for 2-4 weeks prior to the planned surgery for treatment of their prostate cancer. Patient's blood and prostate tissue will be evaluated to determine the effects of the soy supplement on the prostate tissue.

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Key information

Conditions

Prostate Neoplasm Genital Diseases Genital Diseases, Male Genital Neoplasms, Male Male Urogenital Diseases Neoplasms Neoplasms by Site Prostatic Diseases Prostatic Neoplasms Urogenital Diseases Urogenital Neoplasms

Age range

18 year and older

Sex eligibility

Male

Study type

Interventional

Phase

Phase 3

Primary location

VA Medical Center, Kansas City MO

Kansas City, Missouri, 64128, United States

About this study

This is a randomized study evaluating the effectiveness and direct effect a commercial soy supplement has on prostate cancer and normal prostate tissue. Patients will be randomized to either receive placebo or a commercial soy supplement for 2-4 weeks prior to the planned surgery for treatment of their prostate cancer. The specific objectives are:

  • To assess the effect of soy supplementation on endogenous hormone production levels and serum prostate specific antigens.
  • To assess the impact of soy supplementation on estrogen receptor expression(ER).
  • To determine the impact of soy isoflavones on cell cycle regulation and associated gene expression.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Histologically proven prostate cancer.
  • Surgical candidate for prostatectomy.
  • During study period, must agree not to take new supplements.
  • No concurrent chemotherapy, radiation or hormonal therapy.
  • No history of prior allergy to soy based products.
  • Must not have been taking soy supplements or soy isoflavones within 90 days prior to study enrollment.
  • Must be able to safely be on study supplements for period of at least two weeks prior to scheduled prostatectomy.
  • Must give written and informed consent in accordance with institutional and federal guidelines.

Exclusion criteria

During study period, must agree not to take new supplements.

  • No concurrent chemotherapy, radiation or hormonal therapy.
  • No history of prior allergy to soy based products.
  • Must not have been taking soy supplements or soy isoflavones within 90 days prior to study enrollment.
  • Must be able to safely be on study supplements for period of at least two weeks prior to scheduled

Treatment and study plan

Soy Supplement

Drug

Soy protein supplement will be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).

Other names: Fla-vien

Placebo

Drug

Placebo will consist of a capsule without the soy protein added to be taken for 2-4 weeks until surgery to remove the prostate or start of radiation treatment. Patient will receive 4 capsules twice a day (8 capsules) daily to be taken with water or juice (except grapefruit juice).

Other names: No other name

Primary outcomes

  1. Effect of Soy Isoflavones on Serum Testosterone Levels.

    Time frame: Two weeks

    Total testosterone (ng/ml) serum levels were measured at the time of enrollment(baseline), after two weeks on soy supplement(time point 1), and just prior to prostatectomy (time point 2). All patients must have completed at least two week of soy supplement or placebo and time point 3 varied depending on date of planned prostatectomy. Results were analyzed and are reported at the two week time period, comparing between patients receiving soy supplement or placebo.

Secondary outcomes

  1. Effect of Soy Isoflavones on Estrogen Receptor Status

    Time frame: Two weeks

    Samples of the prostate cancer tissue (paraffin embedded) were sectioned and placed on a glass slide. Using immunohistochemistry and an estrogen receptor antibody, sections were stained and assess to determine the extent of estrogen receptor expression. Patients in the soy supplement arm's samples results were compared to placebo arm results.

  2. Molecular Effects of Soy Supplementation Compared to Placebo.

    Time frame: One year

    Using a tissue microarray targeting the cell cycle, selected fresh prostate cancer samples were evaluated in patients in the soy supplement arm compared to the placebo arm.

Sponsors and collaborators

Lead sponsor

VA Office of Research and Development

Fed

Registry information

Official study title

Role of Soy Isoflavones in Prostate Cancer Prevention

Important dates

Study start
2005
Primary completion
2009
Study completion
2009
First posted
Nov 17, 2005
Registry last updated
Jun 18, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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