Anastrozole in Preventing Breast Cancer in Postmenopausal Women at Increased Risk of Breast Cancer (IBIS II)
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|ClinicalTrials.gov Identifier: NCT00078832|
Recruitment Status : Completed
First Posted : March 9, 2004
Last Update Posted : October 6, 2021
RATIONALE: Chemoprevention therapy is the use of certain drugs to try to prevent the development of cancer. Anastrozole may be effective in preventing breast cancer.
PURPOSE: This randomized clinical trial is studying how well anastrozole works in preventing breast cancer in postmenopausal women who are at increased risk for the disease.
|Condition or disease||Intervention/treatment||Phase|
|Breast Cancer||Drug: anastrozole Drug: placebo||Phase 3|
- Determine the effectiveness of anastrozole in preventing breast cancer in postmenopausal women at increased risk for the disease.
- Determine the role of this drug in preventing estrogen receptor-positive breast cancer in these participants.
- Determine the effect of this drug on breast cancer mortality in these participants.
- Determine the effect of this drug on other cancers, cardiovascular disease, fracture rates, and non-breast cancer deaths in these participants.
- Determine the tolerability and acceptability of side effects of this drug in these participants.
OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Participants are stratified according to participating center. Participants are randomized to 1 of 2 treatment arms.
- Arm I: Participants receive oral anastrozole daily for 5 years.
- Arm II: Participants receive an oral placebo daily for 5 years. In both arms, treatment continues in the absence of the development of breast cancer (including ductal carcinoma in situ), a drop in the T-score below minus 4, or the occurrence of a new fragility fracture.
Participants are followed for at least a further 5 years.
Peer Reviewed and Funded or Endorsed by Cancer Research UK
ACCRUAL: A total of 3,864 participants were recruited for this study over 10 years.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||3864 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)|
|Official Title:||International Breast Cancer Intervention Study|
|Study Start Date :||September 2003|
|Actual Primary Completion Date :||December 2013|
|Actual Study Completion Date :||May 31, 2021|
Other Name: Arimidex
Placebo Comparator: placebo
anastrozole 1mg PLACEBO
- Development of histologically confirmed breast cancer, both invasive and non-invasive with median follow-up at 5 years [ Time Frame: Dec 2013 ]
- Breast cancer mortality with median follow-up at 10 years [ Time Frame: Dec 2018 ]
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): NCT00078832
|Study Chair:||Jack Cuzick, PhD||Queen Mary University of London|
|Study Chair:||Anthony Howell||University of Manchester|