Soy Supplements in Treating Patients Undergoing Surgery for Localized Prostate Cancer

Wake Forest University (WFU)

Status and phase: Completed; Phase 2

Conditions: Prostate Cancer

Treatments: Dietary Supplement: soy protein isolate; Other: placebo; Dietary Supplement: soy isoflavones

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT00345813

CCCWFU-98203

CCCWFU-BG03-332

CDR0000466317

Details and patient eligibility

About

RATIONALE: Dietary supplementation with soy may keep prostate cancer from growing in patients planning to undergo surgery.

PURPOSE: This randomized phase II trial is studying a soy supplement to see how well it works compared to a placebo in treating patients undergoing surgery for localized prostate cancer.

Full description

OBJECTIVES:

Primary

• Compare the effect of dietary supplementation with soy vs placebo on biomarkers of cell cycle regulation, proliferation, differentiation, apoptosis, and signaling pathways in patients with localized prostate cancer scheduled to undergo radical prostatectomy.

Secondary

• Compare the toxicity and side effects of these regimens in these patients.
• Compare the dietary patterns of these patients.

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

• Arm I: Patients receive oral soy supplementation daily for 4 weeks.
• Arm II: Patients receive oral placebo supplementation daily for 4 weeks. Patients undergo radical prostatectomy within 21 days after completion of soy or placebo supplementation.

Blood and tissue samples are collected for biomarker analysis using immunohistochemistry.

Enrollment: 62 patients

Sex: Male

Ages: 18 to 120 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

  • Clinically localized disease

• Scheduled for radical prostatectomy

• No evidence of metastatic disease by bone scan or CT scan of the abdomen or pelvis

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• No evidence of active nephrolithiasis
• No history of hypercalcemic syndrome

PRIOR CONCURRENT THERAPY:

• No prior treatment for prostate cancer, including radiotherapy, systemic chemotherapy, surgery, or investigational drugs
• No other concurrent dietary supplementation with soy, cholecalciferol (vitamin D), or fish oil

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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62 participants in 2 patient groups, including a placebo group

Arm I

Experimental group

Description:

Patients receive oral soy supplementation daily for 4 weeks. Patients undergo radical prostatectomy within 21 days after completion of soy supplementation.

Treatment:

Dietary Supplement: soy isoflavones

Dietary Supplement: soy protein isolate

Arm II

Placebo Comparator group

Description:

Patients receive oral placebo supplementation daily for 4 weeks. Patients undergo radical prostatectomy within 21 days after completion of placebo supplementation.

Treatment:

Other: placebo