Anastrozole in Preventing Breast Cancer in Postmenopausal Women at Increased Risk of Breast Cancer (IBIS II)
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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
|Official Title:||International Breast Cancer Intervention Study|
- Development of histologically confirmed breast cancer, both invasive and non-invasive with median follow-up at 5 years [ Time Frame: Dec 2013 ] [ Designated as safety issue: No ]
- Breast cancer mortality with median follow-up at 10 years [ Time Frame: Dec 2018 ] [ Designated as safety issue: No ]
|Study Start Date:||September 2003|
|Estimated Study Completion Date:||January 2022|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
- 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 5 years.
Peer Reviewed and Funded or Endorsed by Cancer Research UK
PROJECTED ACCRUAL: A total of 6,000 participants will be accrued for this study.
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|Study Chair:||Jack Cuzick, PhD||Queen Mary's University|