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NCT00003678 · CITED IN SOURCE DOCUMENTS

Tamoxifen in Treating Women With Breast Cancer

An NCI or FDA source cites this study. A citation does not establish that it applies to an individual diagnosis.

Phase
PHASE3
Status at capture
UNKNOWN
Registry last update
2013-12-19

RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using tamoxifen may fight breast cancer by blocking the uptake of estrogen by the tumor cells. PURPOSE: Randomized phase III trial to compare the effectiveness of at least 2 years of tamoxifen with that of 5 additional years of tamoxifen in treating women who have breast cancer that has been surgically removed.

Open the original ClinicalTrials.gov record → · Download preserved record

What did the study report?

Outcomes, safety and baseline populations are separate source sections. Quality-of-life measures appear under their original outcome titles.

No posted result sections were captured. Registered plans do not establish that a treatment works.

Who could take part
eligibility Criteria
DISEASE CHARACTERISTICS: * Histologically confirmed breast carcinoma that has been completely excised * Clinically relapse free * Must have completed at least two years of adjuvant therapy with tamoxifen for early breast cancer AND have no clear indication for or against receiving further tamoxifen * No significant endometrial hyperplasia * No patients with negligibly low risk of breast cancer death * Hormone receptor status: * Any status allowed PATIENT CHARACTERISTICS: Age: * Not specified Sex: * Female Menopausal status: * Any status allowed Performance status: * Not specified Life expectancy: * Not specified Hematopoietic: * Not specified Hepatic: * Not specified Renal: * Not specified Other: * No other life threatening disease * No retinopathy * No psychiatric disorder or other condition that would preclude study compliance * No serious toxicity (e.g., depression) thought to be due to tamoxifen * Not pregnant or nursing * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * Not specified Endocrine therapy: * See Disease Characteristics Radiotherapy: * Not specified Surgery: * See Disease Characteristics Other: * Any primary treatment allowed
healthy Volunteers
false
sex
FEMALE
std Ages
  1. CHILD
  2. ADULT
  3. OLDER_ADULT
Treatment arms and interventions
interventions
  1. name
    tamoxifen citrate
    type
    DRUG
  2. name
    adjuvant therapy
    type
    PROCEDURE
Study design
allocation
RANDOMIZED
primary Purpose
TREATMENT
Enrollment
count
20000
type
ESTIMATED
Registered outcome plans (not posted results)
primary Outcomes
  1. measure
    All-cause mortality
secondary Outcomes
  1. measure
    Disease recurrence
  2. measure
    Death due to breast cancer, other primary tumors, or cardiovascular causes
Full study description
brief Summary
RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using tamoxifen may fight breast cancer by blocking the uptake of estrogen by the tumor cells. PURPOSE: Randomized phase III trial to compare the effectiveness of at least 2 years of tamoxifen with that of 5 additional years of tamoxifen in treating women who have breast cancer that has been surgically removed.
detailed Description
OBJECTIVES: * Compare the disease-free and overall survival of women with early breast cancer who are randomized to discontinue adjuvant tamoxifen vs those randomized to continue for at least 5 additional years. OUTLINE: This is a randomized study. Patients are stratified for analysis according to duration of tamoxifen given before randomization (2-3 years vs 4-5 years vs 6-7 years vs 8-9 years vs 10 years and over), age (less than 49 vs over 50), and important prognostic factors, including tumor type and grade and nodal and estrogen receptor status. Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients discontinue tamoxifen after at least 2 years of prior treatment. * Arm II: Patients continue treatment with tamoxifen for at least 5 additional years in the absence of unacceptable toxicity or disease progression. Patients are followed annually. Peer Reviewed and Funded or Endorsed by Cancer Research UK PROJECTED ACCRUAL: A total of 8,000-20,000 patients will be accrued for this study.
Source references
references
  1. citation
    Gray R, Davies C, Perry P. Tamoxifen for early breast cancer: better late than never. Ann Oncol. 2000 May;11(5):505-7. doi: 10.1023/a:1008323116265. No abstract available.
    pmid
    10907940
    type
    BACKGROUND
  2. citation
    Rea D, Poole C, Gray R. Adjuvant tamoxifen: how long before we know how long? BMJ. 1998 May 16;316(7143):1518-9. doi: 10.1136/bmj.316.7143.1518. No abstract available.
    pmid
    9582148
    type
    BACKGROUND
  3. citation
    Earl H, Gray R, Kerr D, Lee M. The optimal duration of adjuvant tamoxifen treatment for breast cancer remains uncertain: randomize into aTTom. Clin Oncol (R Coll Radiol). 1997;9(3):141-3. doi: 10.1016/s0936-6555(97)80067-2. No abstract available.
    pmid
    9269542
    type
    BACKGROUND
  4. citation
    Earl H, Baker P, Kerr D, Lee M, Gray R, Baum M. Adjuvant treatment with tamoxifen. Recruitment into studies assessing optimum duration of treatment must continue. BMJ. 1996 Apr 20;312(7037):1036-7. doi: 10.1136/bmj.312.7037.1036b. No abstract available.
    pmid
    8616358
    type
    BACKGROUND
  5. citation
    Gray R. Tamoxifen: how boldly to go where no women have gone before. J Natl Cancer Inst. 1993 Sep 1;85(17):1358-60. doi: 10.1093/jnci/85.17.1358. No abstract available.
    pmid
    8350355
    type
    BACKGROUND
  6. citation
    Poterala JE, Wisinski KB. Abbreviated endocrine therapy duration for low estrogen receptor-positive breast cancer: The counter to extended endocrine therapy. Cancer. 2022 May 1;128(9):1724-1726. doi: 10.1002/cncr.34158. Epub 2022 Feb 25. No abstract available.
    pmid
    35213039
    type
    DERIVED
  7. citation
    Bartlett JMS, Sgroi DC, Treuner K, Zhang Y, Ahmed I, Piper T, Salunga R, Brachtel EF, Pirrie SJ, Schnabel CA, Rea DW. Breast Cancer Index and prediction of benefit from extended endocrine therapy in breast cancer patients treated in the Adjuvant Tamoxifen-To Offer More? (aTTom) trial. Ann Oncol. 2019 Nov 1;30(11):1776-1783. doi: 10.1093/annonc/mdz289.
    pmid
    31504126
    type
    DERIVED
Source notices and limitations
    Discovery and provenance
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      source title
      Breast Cancer Treatment (PDQ®)–Health Professional Version
      source update dates
      1. context
        Updated: April 25, 2025
        datetime
        2025-04-25T12:00:00Z
        display
        April 25, 2025

    Preserved source evidence · Not medical advice