Trial Information

Phase II Randomized Study of Soy Isoflavones in Patients With Localized Prostate Cancer Treated With Radiation Therapy

OBJECTIVES:

- Determine the effect of soy protein isolate (isoflavones) and radiotherapy on the
modulation of biomarkers in patients with localized prostate cancer.

- Determine the toxicity of this regimen in these patients.

- Determine the effect of this regimen on the quality of life of these patients.

OUTLINE: This is a randomized, placebo-controlled study. Patients are randomized to 1 of 2
treatment arms.

- Arm I: Patients receive oral soy protein isolate (isoflavones) twice daily for 6 months
in the absence of disease progression or unacceptable toxicity.

- Arm II: Patients receive an oral placebo twice daily for 6 months in the absence of
disease progression or unacceptable toxicity.

In both arms, patients also undergo radiotherapy while receiving isoflavones or placebo.

Quality of life is assessed periodically.

PROJECTED ACCRUAL: A total of 70 patients will be accrued for this study.