An international multicentre study of tamoxifen versus placebo in women at increased risk of breast cancer

• Register: ISRCTN
• Last refreshed on: 15 March 2021
• Main ID: ISRCTN91879928
• Date of registration: 01/06/2006
• Prospective Registration: No
• Primary sponsor: Queen Mary University of London (UK)
• Public title: An international multicentre study of tamoxifen versus placebo in women at increased risk of breast cancer
• Scientific title: An international multicentre study of tamoxifen versus placebo in women at increased risk of breast cancer
• Date of first enrolment: 14/04/1992
• Target sample size: 7000
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN91879928
• Study type: Interventional
• Study design: A multicentre, randomised clinical trial of 7,000 women aged between 45 and 70 years who have a risk of breast cancer at least twice that of the general population (Prevention)
• Phase: Not Applicable

Countries of recruitment

Australia, Belgium, Finland, Switzerland, United Kingdom

Contacts

• Name: Jack Cuzick

Key inclusion & exclusion criteria

Inclusion criteria:
To be eligible, women must satisfy at least one of the entry criteria listed below:
1. A mammogram must have been taken within the last year indicating no malignant disease
2. A signed consent form must have been obtained

Entry criteria:
The entry criteria was 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
8. 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)*
* These women must have clearly apparent family history indicating at least ten fold increased risk of breast cancer.

Exclusion criteria:
1. Pregnant, or at pregnancy risk. If necessary, pre and peri menopausal women must use non-hormonal contraception during the trial
2. Any previous cancer (except non-melanoma skin cancer or in situ cancer of the cervix)
3. Life expectancy of less than 10 years or other medical condition more serious than the risk of breast cancer
4. Psychologically and physically unsuitable for five years tamoxifen or placebo therapy
5. Current treatment with anti-coagulants
6. Previous deep vein thrombosis or pulmonary embolus
7. Current tamoxifen use


Age minimum:
Age maximum:
Gender: Female

Health Condition(s) or Problem(s) studied

Breast cancer chemoprevention
Cancer
Breast cancer

Intervention(s)

Women were randomised to receive either tamoxifen 20 mg per day for 5 years or placebo

Primary Outcome(s)

The development of histologically confirmed breast cancer, both invasive and non-invasive (i.e. including ductal carcinoma in situ [DCIS].

Secondary Outcome(s)

Other cancers, other serious medical conditions or side effects.

Secondary ID(s)

N/A

2005-003091-38

NCT00002644

Source(s) of Monetary Support

Imperial Cancer Reserach Fund, Cancer Research Campaign, Cancer Research UK

Ethics review

Status:
Approval date:
Contact:

The start of the IBIS I study predated the existence of Multicentre Research Ethics Committees (MREC). However, Central Office for Research Ethics Committees (COREC) have appointed the Central and South Bristol Research Ethics Committee to be the lead REC for the IBIS I study. The Central South Bristol REC reference assigned to study is E3244.

Results

• Results available: Yes
• Date Completed: 30/03/2011