Prolonged Tamoxifen Compared With Shorter Tamoxifen in Treating Patients Who Have Breast Cancer

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Basic Trial Information

PhaseTypeStatusAgeSponsorProtocol IDs
Phase IIITreatmentClosedAny ageOtherCDR0000065596
ATLAS, EU-96064, NCT00003016

Trial Description


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.

Further Study Information


  • 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.

Eligibility Criteria


  • 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

Trial Contact Information

Trial Lead Organizations/Sponsors

Oxford Radcliffe Hospital

    Rodrigo Arriagada, MD, Study Chair

    Link to the current record.
    NLM Identifier NCT00003016 processed this data on April 09, 2015

    Note: Information about this trial is from the database. The versions designated for health professionals and patients contain the same text. Minor changes may be made to the record to standardize the names of study sponsors, sites, and contacts. only lists sites that are recruiting patients for active trials, whereas lists all sites for all trials. Questions and comments regarding the presented information should be directed to