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Tamoxifen Citrate in Patients With Breast Cancer

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00963209
Recruitment Status : Unknown
Verified July 2013 by Dr K. Zaman, Centre Hospitalier Universitaire Vaudois.
Recruitment status was:  Recruiting
First Posted : August 21, 2009
Last Update Posted : August 2, 2013
Information provided by (Responsible Party):
Dr K. Zaman, Centre Hospitalier Universitaire Vaudois

Brief Summary:

RATIONALE: Estrogen can promote growth of endocrine sensitive breast cancer cells. Endocrine therapy with tamoxifen citrate may fight breast cancer by blocking the use of estrogen by the tumor cells. Pharmacokinetics and -genomics can have an impact on the efficacy of the treatment.

PURPOSE: This phase III trial is studying blood samples to see if the level of active metabolites of tamoxifen can be improved in patients with breast cancer.

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: tamoxifen citrate Other: laboratory biomarker analysis Other: pharmacological study Phase 3

Detailed Description:



  • To determine how the increase of tamoxifen citrate dose influences the level of its major metabolites in patients with hormone-sensitive breast cancer.


  • To characterize the population pharmacokinetic profile
  • To investigate the role of the other CYPs
  • To assess the relation between clinical symptoms and CYP2D6 genotypes and/or active metabolites levels
  • To explore the correlation between genotypes/metabolites levels and clinical outcomes in terms of tumor relapse.
  • To assess the feasibility, efficacy, and safety of concentration-guided adjustment of tamoxifen citrate dosage.
  • To conduct other exploratory analysis based on the eventual new data coming up in the future.

OUTLINE: Patients receive oral tamoxifen citrate (at a dose of 40 mg/day) daily for 4 months in the absence of disease progression or unacceptable toxicity.

Blood samples are collected for PK, genotyping, phenotyping, and further analysis.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 140 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Tamoxifen Metabolism and the Impact of Tamoxifen Dose on the Level of the Active Metabolites in Endocrine Sensitive Breast Cancer Patients
Study Start Date : June 2009
Estimated Primary Completion Date : September 2013
Estimated Study Completion Date : December 2013

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Breast Cancer

Arm Intervention/treatment
Experimental: Tamoxifen Drug: tamoxifen citrate
Other: laboratory biomarker analysis
Other: pharmacological study

Primary Outcome Measures :
  1. Determination of CYP2D6 genotype and determination of plasma concentrations of tamoxifen citrate and its metabolites (N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and endoxifen) under the 20 mg daily and 40 mg daily schedules [ Time Frame: Jan 2013 ]

Secondary Outcome Measures :
  1. Patients' characteristics [ Time Frame: prospectively ]
  2. Tumor characteristics [ Time Frame: prospectively ]
  3. Cancer treatments history [ Time Frame: prospectively ]
  4. CYP3A4 (phenotype), and possibly other cytochromes involved in the metabolism and transport of drugs [ Time Frame: prospectively ]
  5. Characteristics of drug intake (date of tx initiation, current dosage and frequency, time of last intake) along with patient-reported adherence, assessed by questionnaire [ Time Frame: prospectively ]
  6. Concomitant medication [ Time Frame: prospectively ]
  7. Presence and quantitation of clinical symptoms [ Time Frame: prospectively ]
  8. Detection and classification of general comorbidities and side effects according to NCI-CTC v3.0 [ Time Frame: prospectively ]
  9. Detection of tumor relapse during the observation period of the study [ Time Frame: prospectively ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


  • Diagnosis of breast cancer

    • Hormone-sensitive breast cancer defined as > 10% estrogen receptor and/or > 10% progesterone receptor positivity by immunohistochemistry
  • Receiving treatment with tamoxifen citrate and must be eligible for exposure to higher doses


  • No history of deep venous thrombosis or pulmonary embolism
  • No history of endometrial carcinoma
  • No known history of vaginal bleeding, endometriosis, endometrial hyperplasia, endometrial hypertrophy, and/or polyps
  • Not pregnant or nursing
  • No contraindication to tamoxifen citrate treatment
  • No known allergy to midazolam or dextromethorphan


  • See Disease Characteristics

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 identifier (NCT number): NCT00963209

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Hôpitaux Universitaire de Genève Recruiting
Genève, Switzerland, 1211
Contact: Alexandre Bodmer, MD    41 22 382 40 14      
Centre Hospitalier Universitaire Vaudois Recruiting
Lausanne, Switzerland, 1011
Contact: Khalil Zaman, MD    41-21-314-0168   
Sponsors and Collaborators
Centre Hospitalier Universitaire Vaudois
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Principal Investigator: Khalil Zaman, MD Centre Hospitalier Universitaire Vaudois

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Responsible Party: Dr K. Zaman, Médecin associé, Centre Hospitalier Universitaire Vaudois Identifier: NCT00963209    
Other Study ID Numbers: CDR0000650376
First Posted: August 21, 2009    Key Record Dates
Last Update Posted: August 2, 2013
Last Verified: July 2013
Keywords provided by Dr K. Zaman, Centre Hospitalier Universitaire Vaudois:
endocrine sensitive
breast cancer
Additional relevant MeSH terms:
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Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Citric Acid
Sodium Citrate
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action
Estrogen Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Selective Estrogen Receptor Modulators
Estrogen Receptor Modulators
Bone Density Conservation Agents