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Prolonged Tamoxifen Compared With Shorter Tamoxifen in Treating Patients Who Have 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: NCT00003016
Recruitment Status : Unknown
Verified October 2002 by National Cancer Institute (NCI).
Recruitment status was:  Active, not recruiting
First Posted : January 27, 2003
Last Update Posted : February 9, 2009
Information provided by:
National Cancer Institute (NCI)

Brief Summary:

RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using tamoxifen may fight breast cancer by reducing the production of estrogen. It is not yet known if prolonged tamoxifen is more effective than shorter tamoxifen therapy following curative treatment for breast cancer.

PURPOSE: This randomized phase III trial is studying giving tamoxifen over a prolonged period of time to see how well it works compared to giving tamoxifen over a shorter period of time in treating patients who have had a breast tumor removed.

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: tamoxifen citrate Procedure: adjuvant therapy Phase 3

Detailed Description:


  • Assess the balance of risks and benefits in prolonging the duration of adjuvant tamoxifen by at least 5 years in patients with curatively treated breast cancer who have already had about 5 years of adjuvant tamoxifen.

OUTLINE: This is a randomized study. After about 5 years of adjuvant tamoxifen, recurrence-free patients are randomized to stop tamoxifen treatment immediately or to continue tamoxifen treatment for at least 5 more years.

Patients are followed annually.

PROJECTED ACCRUAL: Approximately 20,000 patients will be accrued for this study.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 20000 participants
Allocation: Randomized
Primary Purpose: Treatment
Official Title: Reliable Assessment of the Efficacy and Safety of Prolonging the Use of Adjuvant Tamoxifen: A Large, Simple, Randomised Study
Study Start Date : October 1995

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Breast Cancer
U.S. FDA Resources

Primary Outcome Measures :
  1. Overall survival (i.e., all-cause mortality)

Secondary Outcome Measures :
  1. Specific-cause mortality
  2. Incidence of second primary tumors

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


  • Curatively treated carcinoma of the breast
  • Currently taking adjuvant tamoxifen

    • Must be substantial uncertainty as to whether or not to continue tamoxifen (i.e., no clear indication or definite contraindication to further treatment with tamoxifen)



  • Any age

Performance status:

  • Not specified

Life expectancy:

  • Not specified


  • Not specified


  • Not specified


  • Not specified


  • Not pregnant or nursing
  • No contraindications to receiving tamoxifen
  • No other serious medical problems


Biologic therapy:

  • Prior biologic therapy allowed


  • Prior chemotherapy allowed

Endocrine therapy:

  • See Disease Characteristics


  • Prior radiotherapy allowed


  • Prior surgery allowed

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): NCT00003016

United Kingdom
Atlas Trial Office
Oxford, England, United Kingdom, OX2 6HE
Sponsors and Collaborators
University of Oxford
Study Chair: Rodrigo Arriagada, MD Karolinska Institutet Identifier: NCT00003016     History of Changes
Other Study ID Numbers: CDR0000065596
First Posted: January 27, 2003    Key Record Dates
Last Update Posted: February 9, 2009
Last Verified: October 2002

Keywords provided by National Cancer Institute (NCI):
stage I breast cancer
stage II breast cancer
stage IIIA breast cancer
stage IIIB breast cancer
stage IIIC breast cancer

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