Chemoprevention of Prostate Cancer, HDAC Inhibition and DNA Methylation (PBroC)

Portland VA Medical Center

Status

Completed

Conditions

Prostate Cancer Prevention

Treatments

Drug: SFN-rich broccoli sprout extract capsules

Dietary Supplement: Gelatin capsule containing microcrystalline cellulose.

Study type

Interventional

Funder types

Other

Other U.S. Federal agency

NIH

Identifiers

NCT01265953

6232

2P01CA090890-06A2 (U.S. NIH Grant/Contract)

2096 (Other Identifier)

Portland VA-09-0607

Details and patient eligibility

About

The objective of the study is to identify mechanisms by which compounds found in cruciferous vegetables alter gene expression via epigenetic modifications (changes in gene expression) and may prevent prostate cancer development.

The investigators have found that sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, inhibits histone deacetylase (HDAC) activity in human colorectal and prostate cancer cells.

Full description

Prostate cancer is the most frequently diagnosed non-cutaneous cancer and is the second leading cause of cancer death in American men. The precise etiologic factors that initiate and enhance the progression of prostate cancer remain unknown, but epigenetic alterations and diet/lifestyle factors have come forth as significant contributing factors. Epidemiologic studies suggest that cruciferous vegetable intake decreases the risk for prostate cancer. The long-term goal of this proposal is to identify mechanisms by which dietary compounds, such as those found in cruciferous vegetables decrease prostate cancer risk. The objective of the study is to identify mechanisms by which compounds found in cruciferous vegetables alter gene expression via epigenetic modifications and may prevent prostate cancer development.

The investigators have found that SFN, an isothiocyanate found in cruciferous vegetables, inhibits HDAC activity in human colorectal and prostate cancer cells.

Targeting the epigenome, including the use of HDAC and DNA methyltransferase (DNMT) inhibitors, is an evolving strategy for cancer chemoprevention and both have shown promise in cancer clinical trials.

This Randomized, Double Blind, Clinical Trial will address the following objectives:

Identify distribution of SFN and its metabolites and HDAC inhibition following supplementation with an SFN-rich broccoli sprout extract in subjects at risk for prostate cancer (Primary Endpoints)
Investigate the effects of supplementation with an SFN-rich broccoli sprout extract on DNA methylation status and proliferation markers in a pre-biopsy setting (secondary analysis)

The effects of short-term supplementation with an SFN-rich broccoli sprout extract on benign epithelial tissue will be studied in men characterized as being at risk for prostate cancer in a randomized, placebo-controlled trial. Men scheduled for prostate biopsy will be recruited into the trial.

Following successful completion of the consent, two 10 mL blood specimens for study analyses, a 4 mL specimen for total bilirubin assessment will be drawn and the subject will provide a urine sample. The study coordinator will explain the Diet History questionnaires (DHQ) and administer the risk factor and adverse event (AE) questionnaires in order to obtain data on potential confounding dietary variables and gain subjects' baseline symptoms.

The study coordinator will provide the subject with a month' supply of either an SFN-rich broccoli sprout extract (BSE) capsule which consist of 200µmol of sulforaphane (SFN) or matching placebo, as dispensed by the Research Pharmacy. The matching placebo for the BSE consists of a gelatin capsule containing microcrystalline cellulose.

Around every 2 weeks, study coordinator will call to complete AE reporting and any changes in medications or supplements and complete brief cruciferous vegetable intake checklist. Subjects will return any unused study "drug" to the study coordinator at the time of biopsy (or at the 4 week visit if subject's prostate biopsy is delayed).

Enrollment

98 patients

Sex

Male

Ages

21+ years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Men scheduled for a prostate biopsy
Age 21 years or older
Signed informed subject consent

Exclusion criteria

Definitive diagnosis with prostate cancer
Significant active medical illness which in the opinion of the investigator or clinician would preclude protocol treatment
Diagnosis of liver disease as noted on the patient problem list or baseline total bilirubin greater than institutional upper limit of normal
Subject reported allergy or sensitivity to cruciferous vegetables
Use of oral antibiotics, with the exception of doxycycline, within three months prior to randomization
Use of warfarin or need for therapeutic anticoagulation at time of biopsy or at anytime during the course of the trial.
Current oral steroid therapy
Current therapy with valproate or other pharmacological drugs associated with HDAC inhibition
Diagnosed dementia as noted on the patient problem list or other significant mental illness that may impact the subjects' ability to follow instructions or comply with the study protocol
Patient may not be a part of another flagged study
Patients already taking SFN dietary supplements