Vitamin D and Soy Supplements in Treating Patients With Recurrent Prostate Cancer

  • Resize font
  • Print
  • Email
  • Facebook
  • Twitter
  • Google+
  • Pinterest

Basic Trial Information

PhaseTypeStatusAgeSponsorProtocol IDs
Phase IIBiomarker/Laboratory analysis, TreatmentCompletedOver 18NCI, OtherCDR0000554969
P30CA012197, CCCWFU-85106, CCCWFU-IRB00000371, NCT00499408

Trial Description


RATIONALE: Vitamin D and soy extract may be effective in lowering prostate-specific antigen (PSA) levels in patients with recurrent prostate cancer that has not responded to previous treatment.

PURPOSE: This phase II trial is studying how well giving vitamin D together with soy supplements works in treating patients with recurrent prostate cancer.

Further Study Information


  • Test the response of biochemically recurrent prostate cancer to a combination of cholecalciferol (i.e., vitamin D) and soy isoflavones (i.e., soy extract) after failed definitive local therapy as determined by PSA response.

OUTLINE: Patients receive oral cholecalciferol twice daily and a soy supplement (i.e., soy bar or shake) once daily. Treatment continues for 3-12 months in the absence of disease progression or unacceptable toxicity.

Blood samples are obtained at baseline and periodically during study to measure serum PSA, serum calcium, plasma cholecalciferol, and plasma soy isoflavone levels. Blood samples are also analyzed for expression of cholecalciferol receptor, p21, and p27 in peripheral blood lymphocytes as surrogate markers of the actions of cholecalciferol and genistein. Protein expression is assessed by immunoblot analysis of cell lysates as well as quantitative polymerase chain reaction.

Patients complete a toxicity questionnaire once each month to assess for cholecalciferol and soy supplementation toxicities and symptoms of hypercalcemia.

After completion of study therapy, patients are followed every 3 months for 1 year.

Eligibility Criteria


  • Age > 18 years
  • Histologically confirmed adenocarcinoma of the prostate
  • Biochemical relapse following definitive therapy by ASTRO criteria (PSA with 3 consecutive rising measurements separated by at least one month) and minimum PSA ≥ 1.0 ng/mL
  • PSA doubling time of ≥ 6 months, as demonstrated by 3 PSA measurements obtained ≥ 2 months apart
  • No hormonal therapy in 6 months prior to enrollment
  • ECOG performance status 0-2
  • Life expectancy > 3 months
  • At least 2 years since prior definitive radiotherapy
  • No concurrent cholecalciferol, calcium, or soy supplements
  • Absolute granulocyte count ≥ 1,000/mm³
  • Platelet count ≥ 100,000/mm³
  • Hemoglobin ≥ 9.0 g/dL
  • Creatinine ≤ 2.0 mg/dL
  • Total bilirubin ≤ 2.0 mg/dL
  • Calcium > 8.5 mg/dL and < 10.5 mg/dL
  • Testosterone ≥ 150 ng/dL


  • No clinically evident brain metastases
  • Concurrent cholecalciferol, calcium, or soy supplements
  • Concurrent chemotherapy with nonstudy drugs
  • Serious medical illness that would limit survival to < 3 months, or psychiatric condition that would preclude giving informed consent
  • Other malignancy except nonmelanoma skin cancer, adequately treated stage I or II cancer from which the patient is currently in complete remission, or any other cancer from which the patient has been disease-free for the past 5 years
  • Active, uncontrolled bacterial, viral, or fungal infection
  • Hemorrhagic disorder
  • Evidence of metastatic disease by bone scan or CT scan
  • History of hypercalcemia
  • More History of exposure to other phytotherapeutics, including PC-SPES and Saw Palmetto, within the last year.

Trial Contact Information

Trial Lead Organizations/Sponsors

Wake Forest University Comprehensive Cancer Center

  • National Cancer Institute
K.C. Balaji, MD, Study Chair

Link to the current record.
NLM Identifier NCT00499408 processed this data on April 09, 2015

Note: Information about this trial is from the database. The versions designated for health professionals and patients contain the same text. Minor changes may be made to the record to standardize the names of study sponsors, sites, and contacts. only lists sites that are recruiting patients for active trials, whereas lists all sites for all trials. Questions and comments regarding the presented information should be directed to