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Tamoxifen for the Prevention of Breast Cancer in High-Risk Women

This study has been completed.
Information provided by:
National Cancer Institute (NCI) Identifier:
First received: November 1, 1999
Last updated: September 19, 2013
Last verified: July 2011

RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using tamoxifen may fight breast cancer by blocking the uptake of estrogen.

PURPOSE: Randomized double-blinded phase III trial to compare the effectiveness of tamoxifen with a placebo in preventing breast cancer in women at high risk.

Condition Intervention Phase
Breast Cancer Drug: tamoxifen citrate Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Masking: Double
Primary Purpose: Prevention

Resource links provided by NLM:

Further study details as provided by National Cancer Institute (NCI):

Estimated Enrollment: 7000
Study Start Date: January 1994
Study Completion Date: May 2011
Detailed Description:

OBJECTIVES: I. Evaluate whether tamoxifen taken daily for 5 years reduces the incidence of and mortality from breast cancer in high-risk women. II. Assess the risks and benefits of this intervention.

OUTLINE: This is a randomized, double-blind, placebo-controlled study. Participants are stratified by participating institution. Participants are randomly assigned to receive either oral tamoxifen or oral placebo every day for 5 years in the absence of breast cancer development or pregnancy. Participants are followed every 6 months for 5 years; then annually for 5 years. Peer Reviewed and Funded or Endorsed by Cancer Research UK

PROJECTED ACCRUAL: 7,000 women will be entered at a rate of 200-500 women/institution/5 years.


Ages Eligible for Study:   35 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

DISEASE CHARACTERISTICS: See General Eligibility Criteria

PATIENT CHARACTERISTICS: Age: 35 to 70 Sex: Women only Menopausal status: Pre-, peri-, or postmenopausal Performance status: Not specified Life expectancy: At least 10 years Cardiovascular: No prior deep vein thrombosis Pulmonary: No prior pulmonary embolus Other: Psychologically and physically able to undertake therapy for 5 years No other medical condition more serious than risk of breast cancer No prior cancer except: Nonmelanomatous skin cancer In situ cancer of the cervix No pregnant women Effective nonhormonal contraception required of fertile women

PRIOR CONCURRENT THERAPY: Hormone replacement therapy for menopausal symptoms allowed at lowest effective dose Not currently on tamoxifen Not currently on anticoagulants

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Please refer to this study by its identifier: NCT00002644

United Kingdom
Imperial Cancer Research Fund
London, England, United Kingdom, WC2A 3PX
Sponsors and Collaborators
Institute of Cancer Research, United Kingdom
Study Chair: Jack Cuzick, PhD Cancer Research UK
  More Information

Publications: Identifier: NCT00002644     History of Changes
Other Study ID Numbers: CDR0000064151
Study First Received: November 1, 1999
Last Updated: September 19, 2013

Keywords provided by National Cancer Institute (NCI):
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 processed this record on September 21, 2017