Anastrozole in Preventing Breast Cancer in Postmenopausal Women at Increased Risk of Breast Cancer — IBIS II  

Breast Cancer Clinical Trial

Official title: International Breast Cancer Intervention Study

Status Completed

Clinical Trial Summary

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.

Clinical Trial Description

OBJECTIVES:

Primary

• Determine the effectiveness of anastrozole in preventing breast cancer in postmenopausal women at increased risk for the disease.

Secondary

• 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. ;

Related Conditions & MeSH terms

• Breast Cancer
• Breast Neoplasms

• NCT number: NCT00078832
• Study type: Interventional
• Source: Queen Mary University of London
• Status: Completed
• Phase: Phase 3
• Start date: September 2003
• Completion date: May 31, 2021