Tamoxifen Citrate in Patients With Breast Cancer

Vaud University Hospital Center

Status and phase

Unknown

Phase 3

Conditions

Breast Cancer

Treatments

Drug: tamoxifen citrate

Other: laboratory biomarker analysis

Other: pharmacological study

Study type

Interventional

Funder types

Other

Identifiers

NCT00963209

CHUV-CEPO-TM

EU-20973

CDR0000650376

Details and patient eligibility

About

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.

Full description

OBJECTIVES:

Primary

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

Secondary

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.

Enrollment

140 estimated patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion and exclusion criteria

DISEASE CHARACTERISTICS:

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

PATIENT CHARACTERISTICS:

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

PRIOR CONCURRENT THERAPY: