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Diindolylmethane in Treating Patients With Breast Cancer

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ClinicalTrials.gov Identifier: NCT01391689
Recruitment Status : Completed
First Posted : July 12, 2011
Last Update Posted : November 6, 2017
National Cancer Institute (NCI)
Information provided by (Responsible Party):
University of Arizona

Brief Summary:
This phase II/III trial studies how well diindolylmethane (DIM) works and compares it to placebo in treating patients with breast cancer. DIM may slow the growth of tumor cells and be an effective treatment for breast cancer.

Condition or disease Intervention/treatment Phase
Stage IA Breast Cancer Stage IB Breast Cancer Stage II Breast Cancer Stage IIIA Breast Cancer Dietary Supplement: diindolylmethane Dietary Supplement: placebo Not Applicable

Detailed Description:


I. Assess change in breast density using mammogram-based breast density measures as well as a novel, quantitative fat-water ratio breast magnetic resonance imaging (FWR-MRI).

II. Evaluate the effect of an escalating daily dose of DIM on serum steroid hormones (estrogen, sex hormone binding globulin [SHBG]) and urinary 2-hydroxyestrone:16 alpha-hydroxyestrone (2OHE1:16 alpha OHE1) ratio as well as serum tamoxifen (TAM) metabolites (endoxifen). The study will be initiated at a dose of 75 mg twice daily (BID) (total daily dose of 150 mg) for the first 10 study participants and then the dose will be escalated to 150 mg DIM BID (total daily dose of 300 mg) if no treatment-related serious adverse events (SAEs) are reported in the initial 10 subjects thru 3 months of treatment.

III. Expand on currently available toxicity and safety of DIM-TAM combination by assessing reports of treatment associated side effects/adverse events including TAM-associated endometrial toxicity (self-reported vaginal bleeding patterns and physician ordered vaginal ultrasound), chemistry profiles, Functional Assessment of Cancer Therapy-Endocrine Subscale (FACT-ES) scores and standard Common Terminology Criteria for Adverse Events (CTCAE) tracking.


I. Collect fine-needle aspiration breast tissue samples (in a subset) and blood samples (all participants) in order to explore change in mammary gland tissue architecture and cellularity; and tissue markers and their association with change in breast density and to explore changes in biomarkers of disease risk (e.g. cyclooxygenase-2 [COX-2], deoxyribonucleic acid [DNA] adducts, oxidative stress, inflammation, etc) over time (pre and post treatment) in both study arms.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

ARM I: Patients receive diindolylmethane orally (PO) BID for approximately 36 months.

ARM II: Patients receive placebo PO BID for approximately 36 months.

In both arms, treatment continues in the absence of unacceptable toxicity.

After completion of study treatment, patients are followed up periodically.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 144 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Evaluation of Diindolylmethane Supplementation to Modulate Tamoxifen Efficacy in Breast Cancer The Diindolylmethane Efficacy Study
Study Start Date : February 2011
Actual Primary Completion Date : September 2014
Actual Study Completion Date : July 31, 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Breast Cancer

Arm Intervention/treatment
Experimental: Arm I (antineoplastic therapy)
Patients receive diindolylmethane (BioResponse) PO BID for approximately 18 months.
Dietary Supplement: diindolylmethane
Given PO
Other Name: DIM

Placebo Comparator: Arm II (placebo)
Patients receive placebo PO BID for approximately 18 months.
Dietary Supplement: placebo
Given PO
Other Name: PLCB

Primary Outcome Measures :
  1. Urinary 2OHE1:16alpha OHE1 ratio [ Time Frame: Up to 18 months ]
    estrogen metabolites measured in ng/100ul; this outcome will also be reported as a ratio

Secondary Outcome Measures :
  1. Plasma TAM metabolites (ng/mL) [ Time Frame: Up to 18 months ]
    measures of 4 primary metabolites (UCSF)

  2. Serum Estrogen (estradiol) (pg/mL) [ Time Frame: Up to 18 months ]
    measured at U Michigan

  3. Self reported vaginal bleeding [ Time Frame: Up to 24 months ]
    If vaginal ultrasound is available via medical records, toxicity will be addressed through endometrial evaluation. Otherwise, evaluation will be based on self report.

  4. mammographic density [ Time Frame: up to 18 months ]
    assessed by fat:water ratio magnetic resonance imaging AND mammographic density from clinical mammograms

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Prescribed TAM as adjuvant therapy for early stage (0, I, II, IIIa) breast cancer or as chemoprevention in women at high risk for breast cancer
  • New or planned prescription of TAM therapy; ineligible for randomization until on TAM for > 3 months with the expectation to continue use for > 18 months
  • Mammogram with Breast Imaging Reporting and Data System (BIRADS) score of >= 2; (equivalent to the following and similar breast density descriptive terms found in mammogram reports: 2 = scattered fibroglandular elements/densities; 3 = heterogeneously dense tissue; 4 = extremely dense tissue)
  • No use of soy-based dietary supplements or willingness to discontinue use, complete a 4-week wash-out period, prior to randomization, and refrain from use during trial period
  • If pre-menopausal, non-pregnant (confirmed with urinary pregnancy test); practicing birth control or s/p oophorectomy
  • Able to complete study run-in activities, including taking study-provided placebo pill twice daily (AM & PM) and recording pill intake and any symptoms experienced on a study calendar, with a compliance rate of at least 80%
  • Normal blood chemistry test that includes sodium and specific kidney and liver function tests (creatinine, alanine amino transferase-ALT, aspartate amino transferase-AST) within 30 days of study enrollment; (Informed Consent Form signed)
  • No history of hyponatremia

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01391689

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United States, Arizona
Arizona Cancer Center
Tucson, Arizona, United States, 85012
Sponsors and Collaborators
University of Arizona
National Cancer Institute (NCI)
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Principal Investigator: Cynthia Thomson University of Arizona
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: University of Arizona
ClinicalTrials.gov Identifier: NCT01391689    
Other Study ID Numbers: 10-0366-04
NCI-2011-00710 ( Registry Identifier: CTRP (Clinical Trial Reporting Program) )
R01CA149417-01A1 ( U.S. NIH Grant/Contract )
First Posted: July 12, 2011    Key Record Dates
Last Update Posted: November 6, 2017
Last Verified: April 2016
Additional relevant MeSH terms:
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Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Anticarcinogenic Agents
Protective Agents
Physiological Effects of Drugs
Antineoplastic Agents