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Chemoprevention of Prostate Cancer, HDAC Inhibition and DNA Methylation

Chemoprevention of Prostate Cancer, HDAC Inhibition and DNA Methylation

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01265953
Acronym
PBroC
Enrollment
98
Registered
2010-12-23
Start date
2011-07-31
Completion date
2015-12-31
Last updated
2019-05-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer Prevention

Keywords

cancer prevention, isothiocyanate, sulforaphane

Brief summary

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.

Detailed 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: 1. 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) 2. 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).

Interventions

DRUGSFN-rich broccoli sprout extract capsules

Four weeks SFN-rich broccoli sprout extract (BSE) capsules: 200µmol of SFN, 2 capsules (1 capsule B.I.D.) daily

DIETARY_SUPPLEMENTGelatin capsule containing microcrystalline cellulose.

Four weeks placebo capsules: 2 capsules (1 capsule B.I.D.) daily

Sponsors

National Cancer Institute (NCI)
CollaboratorNIH
Oregon State University
CollaboratorOTHER
OHSU Knight Cancer Institute
CollaboratorOTHER
Portland VA Medical Center
Lead SponsorFED

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender
MALE
Age
21 Years to No maximum
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Change of Total Urine SFN (Sulforaphane) MetabolitesBaseline and 4-8 weeks following interventionCollection of blood and urine specimens occurred at pre-intervention and post-intervention. Change = post-intervention level minus pre-intervention level
Change of Total Plasma SFN (Sulforaphane) Metabolites LevelBaseline and 4-8 weeks following interventionIn subjects at risk for prostate cancer, presence of SFN was analyzed in plasma. Collection of blood specimens occurred at pre-intervention and post-intervention. The Change = post-intervention level minus pre-intervention level
Percentage of Ki67 Positive Cells up to 8 Weeks Post-randomizationBaseline and 4-8 weeks following intervention; prostate biopsy were collected post-intervention when clinically-indicatedKi67 is a biomarker of disease progression. Immunohistochemical (IHC) analysis of Ki67 was performed using research only prostate biopsy specimens collected post-intervention at the time of the clinically-indicated prostate biopsy.
Expression of Histone Deacetylase 6 (HDAC6)Baseline and 4-8 weeks following intervention; prostate biopsy were collected post-intervention when clinically-indicatedImmunohistochemical (IHC) analysis of HDAC6 expression using research-only prostate biopsy tissue collected post-intervention at the time of the clinically-indicated prostate biopsy. A modified Histo-score (H-score) was calculated, which involved semiquantitative assessment of both staining intensity (graded as 1-3 with 1 representing weak staining, 2 moderate, and 3 strong) and percentage of positive cells. H-score ranged from 0 to 300 with 300 the strongest expression.

Countries

United States

Participant flow

Participants by arm

ArmCount
Broccoli Sprout Extract Capsules
Four weeks broccoli sprout extract (BSE) capsules: 200µmol of sulforaphane (SFN) daily, 2 capsules (1 capsule B.I.D.) daily
50
Placebo Capsules
Four weeks placebo capsules: 2 capsules (1 capsule B.I.D.) daily Dietary Supplement: Gelatin capsule containing microcrystalline cellulose
48
Total98

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyNon compliance53

Baseline characteristics

CharacteristicBroccoli Sprout Extract CapsulesPlacebo CapsulesTotal
Age, Continuous65.7 years
STANDARD_DEVIATION 5.4
64.9 years
STANDARD_DEVIATION 5
65.3 years
STANDARD_DEVIATION 5.2
BMI28.9 kg/m^2
STANDARD_DEVIATION 7.6
31.1 kg/m^2
STANDARD_DEVIATION 6.4
30.0 kg/m^2
STANDARD_DEVIATION 7.1
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
1 Participants1 Participants2 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants1 Participants2 Participants
Race (NIH/OMB)
White
48 Participants46 Participants94 Participants
Region of Enrollment
United States
50 Participants48 Participants98 Participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
50 Participants48 Participants98 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 500 / 48
other
Total, other adverse events
2 / 501 / 48
serious
Total, serious adverse events
0 / 500 / 48

Outcome results

Primary

Change of Total Plasma SFN (Sulforaphane) Metabolites Level

In subjects at risk for prostate cancer, presence of SFN was analyzed in plasma. Collection of blood specimens occurred at pre-intervention and post-intervention. The Change = post-intervention level minus pre-intervention level

Time frame: Baseline and 4-8 weeks following intervention

Population: We missed blood samples from some subjects, therefore, total number of subjects analyzed for the plasma-based analysis is different from the number of total enrolled subjects.

ArmMeasureValue (MEAN)Dispersion
SupplementChange of Total Plasma SFN (Sulforaphane) Metabolites Level0.12 micromolar (µM)Standard Error 0.03
PlaceboChange of Total Plasma SFN (Sulforaphane) Metabolites Level-0.0003 micromolar (µM)Standard Error 0.0002
Primary

Change of Total Urine SFN (Sulforaphane) Metabolites

Collection of blood and urine specimens occurred at pre-intervention and post-intervention. Change = post-intervention level minus pre-intervention level

Time frame: Baseline and 4-8 weeks following intervention

Population: Not all subjects had urine samples for analysis, therefore, the total number of subjects in this urine analysis is different from total number of enrolled subjects.

ArmMeasureValue (MEAN)Dispersion
SupplementChange of Total Urine SFN (Sulforaphane) Metabolites4.75 micromolar (µM) concentrations of urinaStandard Error 0.64
PlaceboChange of Total Urine SFN (Sulforaphane) Metabolites-0.02 micromolar (µM) concentrations of urinaStandard Error 0.01
Primary

Expression of Histone Deacetylase 6 (HDAC6)

Immunohistochemical (IHC) analysis of HDAC6 expression using research-only prostate biopsy tissue collected post-intervention at the time of the clinically-indicated prostate biopsy. A modified Histo-score (H-score) was calculated, which involved semiquantitative assessment of both staining intensity (graded as 1-3 with 1 representing weak staining, 2 moderate, and 3 strong) and percentage of positive cells. H-score ranged from 0 to 300 with 300 the strongest expression.

Time frame: Baseline and 4-8 weeks following intervention; prostate biopsy were collected post-intervention when clinically-indicated

Population: Some subjects did not have post-intervention prostate tissue that can be used for IHC analysis, therefore, the overall number of participants analyzed for IHC analysis is different from the total enrolled subjects.

ArmMeasureValue (MEAN)Dispersion
SupplementExpression of Histone Deacetylase 6 (HDAC6)187 H-scoreStandard Error 13
PlaceboExpression of Histone Deacetylase 6 (HDAC6)183 H-scoreStandard Error 12.5
Primary

Percentage of Ki67 Positive Cells up to 8 Weeks Post-randomization

Ki67 is a biomarker of disease progression. Immunohistochemical (IHC) analysis of Ki67 was performed using research only prostate biopsy specimens collected post-intervention at the time of the clinically-indicated prostate biopsy.

Time frame: Baseline and 4-8 weeks following intervention; prostate biopsy were collected post-intervention when clinically-indicated

Population: Some subjects did not have post-intervention prostate tissue that can be used for IHC analysis, therefore, the overall number of participants analyzed for IHC analysis is different from the total enrolled subjects.

ArmMeasureValue (MEAN)Dispersion
SupplementPercentage of Ki67 Positive Cells up to 8 Weeks Post-randomization1.8 percent positiveStandard Error 0.2
PlaceboPercentage of Ki67 Positive Cells up to 8 Weeks Post-randomization1.9 percent positiveStandard Error 0.3

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026