This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Study of Tamoxifen Dose Escalation in Breast Cancer Patients With CYP2D6 Polymorphisms (TADE)

This study has been completed.
St George Hospital, Australia
Information provided by (Responsible Party):
Howard Gurney, Western Sydney Local Health District Identifier:
First received: February 24, 2010
Last updated: May 3, 2013
Last verified: May 2013
Tamoxifen is an important drug for the treatment of breast cancer. Used adjuvantly after operation in early breast cancer, tamoxifen reduces annual recurrence rate by half and cancer death by one third. Used preventatively it also reduces the risk of breast cancer by 50% in women at high risk for developing the disease Tamoxifen needs to be activated in the body to an active form called endoxifen, mainly by the enzyme called CYP2D6. Patients have variable capability to activate tamoxifen due to variable function of this enzyme. Studies showed clear correlation of specific genetic variant of CYP2D6 with endoxifen blood levels. It is estimated that up to 25% Caucasian population have reduced or even absent CYP2D6 function. More recently, there were studies that showed the correlation with genetic variant of CYP2D6 and breast cancer relapse in early breast cancer patients treated with tamoxifen. Food and Drug Authority (FDA) in America and recommended checking CYP2D6 genotype in patients receiving tamoxifen treatment, but they did not specify how to interpret the genotype results and what kind actions to take in patient with adverse genotype. The aim of the investigators study is to see if increasing tamoxifen in patients with genetic polymorphism of CYP2D6 will increase endoxifen level to the same range of most patients who have wild type (normal functional)CYP2D6.

Condition Intervention
Breast Cancer CYP2D6 Polymorphism Drug: Tamoxifen

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: A Multi-Centre Study of Tamoxifen Dose Escalation Study in Breast Cancer Patients With CYP2D6 Polymorphisms

Resource links provided by NLM:

Further study details as provided by Howard Gurney, Western Sydney Local Health District:

Primary Outcome Measures:
  • Effects of genotype of CYP2D on plasma and serum concentration of tamoxifen and its metabolites, with consequent recommendation for dosage adjustment [ Time Frame: dose escalation over 40 weeks ]
  • To test whether Tamoxifen dose escalation in patients with genetic polymorphism of CYP2D6 will increase endoxifen blood levels to a target level [ Time Frame: Dose escalation over 40 weeks ]
  • Correlate tamoxifen and its metabolites concentration with tamoxifen side effects [ Time Frame: dose escalation over 40 weeks ]

Enrollment: 121
Study Start Date: March 2010
Study Completion Date: December 2012
Primary Completion Date: October 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Tamoxifen
Dose escalation of tamoxifen in patients with low endoxifen levels
Drug: Tamoxifen
Dose escalation


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

Inclusion Criteria:

  • ECOG performance status ≤ 1
  • Life expectancy ≥ 6 months
  • Histologically or cytologically confirmed early, locally advanced or metastatic breast cancer
  • Oestrogen receptor positive
  • About to start tamoxifen treatment or already on tamoxifen 20mg daily
  • Adequate hepatic and renal function

Exclusion Criteria:

  • Concurrent chemotherapy or radiotherapy
  • Treatment with medications that may alter cytochrome P450 (CYP450)3A4/5 and CYP2D6 activities
  • History of thrombosis
  • History of non-compliance with previous or current treatment;
  • Medical or psychiatric conditions that compromise the patient's ability to give informed consent
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01075802

Australia, New South Wales
St George Hospital
Sydney, New South Wales, Australia
Westmead Cancer Care Centre
Westmead, New South Wales, Australia, 2145
Sponsors and Collaborators
Western Sydney Local Health District
St George Hospital, Australia
Principal Investigator: Howard Gurney, MBBS,FRACP South West Sydney Local Health District
  More Information

Responsible Party: Howard Gurney, A/Prof Howard Gurney, Western Sydney Local Health District Identifier: NCT01075802     History of Changes
Other Study ID Numbers: TADE study
Study First Received: February 24, 2010
Last Updated: May 3, 2013

Keywords provided by Howard Gurney, Western Sydney Local Health District:
Breast cancer
polymorphism of CYP2D6

Additional relevant MeSH terms:
Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
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 processed this record on September 21, 2017