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Tamoxifen for the Prevention of Breast Cancer in High-Risk Women (IBIS-1)

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.
 
ClinicalTrials.gov Identifier: NCT00002644
Recruitment Status : Active, not recruiting
First Posted : May 11, 2004
Last Update Posted : February 26, 2019
Sponsor:
Information provided by (Responsible Party):
Queen Mary University of London

Brief Summary:
The International Breast Cancer Intervention Study I (IBIS-I) was designed to investigate the use of tamoxifen in preventing breast cancer in women with a higher risk of developing the disease. Recruitment of women to IBIS-I ended in March 2001 and it recruited 7154 women from 36 centres in 9 countries. The results of the study showed that tamoxifen reduced the incidence of breast cancer by one third in these high risk women but with some serious side effects. IBIS-II was designed to continue the work started in IBIS-I by examining the role of anastrozole in the prevention of breast cancer which we hope will reduce breast cancer by even more than tamoxifen with less serious side effects.

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: Tamoxifen Citrate 20Mg Tab Other: Placebo Phase 3

Detailed Description:

Established in 1992, the IBIS-I Study investigated the efficacy of tamoxifen (a hormonal drug used to prevent breast cancer) versus a placebo drug (taken daily for five years) in terms of reduction of breast cancer incidence in pre and postmenopausal women at high risk of developing breast cancer. It was a double-blind, randomised placebo-controlled trial that recruited 7,154 women internationally (of which 4,277 were UK participants), aged 35-70 years. The primary outcome measure was the incidence of breast cancer, including ductal carcinoma in situ (cancer cells in the lining of the breast milk duct) and side effects present in the patients were also investigated.

Recruitment to the study completed in 2001 and the intervention (placebo/tamoxifen) ended in 2007. In early 2008 the Research Ethics Committee (REC) approved the conversion of IBIS-I to an epidemiological cohort study. During 2007-2016 participants were followed-up via an annual postal questionnaire.

In 2002, initial results found that tamoxifen reduced the risk of invasive breast cancer by 31%. Mortality from non-breast cancer causes was not increased by tamoxifen. However, the analysis concluded that the overall risk/benefit ratio for the use of tamoxifen in prevention remained unclear and that continued follow-up of trial participants was essential. A 2007 analysis on long-term tamoxifen prophylaxis for breast cancer confirmed the preventive effect of tamoxifen in terms of breast cancer incidence and that this was constant for the entire follow-up period. No reduction in size of benefit was observed for up to ten years following participant randomisation. Additionally, tamoxifen-related side effects such as thrombo-embolism were not increased anymore after the 5-year treatment period. These results therefore demonstrate that the benefit-to-risk ratio of tamoxifen improves with increasing duration of follow-up. Thus, how much additional benefit will be seen long-term remains an important question.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 7154 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Masking Description: Double-blind
Primary Purpose: Prevention
Official Title: International Breast Cancer Intervention Study: A Multicentre Trial of Tamoxifen to Prevent Breast Cancer
Actual Study Start Date : January 1994
Actual Primary Completion Date : January 2001
Estimated Study Completion Date : December 2024

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Breast Cancer

Arm Intervention/treatment
Experimental: Tamoxifen citrate
Tamoxifen citrate 20 mg/day for 5 years
Drug: Tamoxifen Citrate 20Mg Tab
Tamoxifen Citrate 20Mg Tab

Placebo Comparator: Placebo
Placebo 20 mg/day for 5 years
Other: Placebo
Placebo 20Mg Tab





Information from the National Library of Medicine

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

The entry criteria are based on a relative risk of at least two-fold for women aged 45-70 years, four-fold for women aged 40-44 years and ten-fold for women aged 35-39 years.

Age 45-70 years

  1. First degree relative who developed breast cancer at age 50 or less
  2. First degree relative who developed bilateral breast cancer
  3. Two or more first or second degree relatives who developed breast cancer
  4. Nulliparous and a first degree relative who developed breast cancer
  5. Benign biopsy with proliferative disease and a first degree relative who developed breast cancer
  6. Lobular carcinoma in situ
  7. Atypical ductal or lobular hyperplasia in a benign lesion

19)Women at high risk who do not fit into the above categories (risk equivalent)*

* These women must have clearly apparent family history indicating at least two fold increased risk of breast cancer.

Age 40-44 years 8) Two or more first or second degree relatives who developed breast cancer at age 50 or less 9) First degree relative with bilateral breast cancer who developed the first breast cancer at age 50 or less 10) Nulliparous and a first degree relative who developed breast cancer at age 40 or less 11) Benign biopsy with proliferative disease and a first degree relative who developed breast cancer at age 40 or less 12) Lobular carcinoma in situ 13) Atypical ductal or lobular hyperplasia in a benign lesion 14) Women at high risk who do not fit into the above categories (risk equivalent)*

* These women must have clearly apparent family history indicating at least four fold increased risk of breast cancer.

Age 35-39 years 15) Two or more first degree relatives who developed breast cancer at age 50 or less 16) First degree relative with bilateral breast cancer who developed the first breast cancer at age 40 or less 17) Lobular carcinoma in situ 18) Women at high risk who do not fit into the above categories (risk equivalent)*


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 ClinicalTrials.gov identifier (NCT number): NCT00002644


Locations
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United Kingdom
Queen Mary University of London
London, England, United Kingdom, EC1M6BQ
Sponsors and Collaborators
Queen Mary University of London
Investigators
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Study Chair: Jack Cuzick, PhD Queen Mary University of London
Publications of Results:

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Responsible Party: Queen Mary University of London
ClinicalTrials.gov Identifier: NCT00002644    
Other Study ID Numbers: CDR0000064151
2005-003091-38 ( EudraCT Number )
ISRCTN91879928 ( Registry Identifier: ISRCTN )
First Posted: May 11, 2004    Key Record Dates
Last Update Posted: February 26, 2019
Last Verified: February 2019

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by Queen Mary University of London:
breast cancer
tamoxifen
prevention
IBIS
Additional relevant MeSH terms:
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Breast Neoplasms
Neoplasms by Site
Neoplasms
Breast Diseases
Skin Diseases
Tamoxifen
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