Tamoxifen for the Prevention of Breast Cancer in High-Risk Women
NCT ID: NCT00002644
Last Updated: 2024-12-11
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
PHASE3
7154 participants
INTERVENTIONAL
1994-01-31
2011-03-30
Brief Summary
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Detailed Description
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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.
Conditions
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Keywords
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Study Design
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RANDOMIZED
PARALLEL
PREVENTION
TRIPLE
Study Groups
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Tamoxifen citrate
Tamoxifen citrate 20 mg/day for 5 years
Tamoxifen Citrate 20Mg Tab
Tamoxifen Citrate 20Mg Tab
Placebo
Placebo 20 mg/day for 5 years
Placebo
Placebo 20Mg Tab
Interventions
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Tamoxifen Citrate 20Mg Tab
Tamoxifen Citrate 20Mg Tab
Placebo
Placebo 20Mg Tab
Eligibility Criteria
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Inclusion Criteria
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)\*
Exclusion Criteria
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/placebo therapy.
5. Current treatment with anti-coagulants.
6. Previous deep vein thrombosis or pulmonary embolus.
7. Current tamoxifen use.
35 Years
70 Years
FEMALE
No
Sponsors
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Queen Mary University of London
OTHER
Responsible Party
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Principal Investigators
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Jack Cuzick, PhD
Role: STUDY_CHAIR
Queen Mary University of London
Locations
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Queen Mary University of London
London, England, United Kingdom
Countries
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References
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Cuzick J, Warwick J, Pinney E, Duffy SW, Cawthorn S, Howell A, Forbes JF, Warren RM. Tamoxifen-induced reduction in mammographic density and breast cancer risk reduction: a nested case-control study. J Natl Cancer Inst. 2011 May 4;103(9):744-52. doi: 10.1093/jnci/djr079. Epub 2011 Apr 11.
Stone J, Warren RM, Pinney E, Warwick J, Cuzick J. Determinants of percentage and area measures of mammographic density. Am J Epidemiol. 2009 Dec 15;170(12):1571-8. doi: 10.1093/aje/kwp313. Epub 2009 Nov 12.
Cuzick J, Forbes JF, Sestak I, Cawthorn S, Hamed H, Holli K, Howell A; International Breast Cancer Intervention Study I Investigators. Long-term results of tamoxifen prophylaxis for breast cancer--96-month follow-up of the randomized IBIS-I trial. J Natl Cancer Inst. 2007 Feb 21;99(4):272-82. doi: 10.1093/jnci/djk049.
Sestak I, Kealy R, Edwards R, Forbes J, Cuzick J. Influence of hormone replacement therapy on tamoxifen-induced vasomotor symptoms. J Clin Oncol. 2006 Aug 20;24(24):3991-6. doi: 10.1200/JCO.2005.04.3745.
Cuzick J, Warwick J, Pinney E, Warren RM, Duffy SW. Tamoxifen and breast density in women at increased risk of breast cancer. J Natl Cancer Inst. 2004 Apr 21;96(8):621-8. doi: 10.1093/jnci/djh106.
Cuzick J, Forbes J, Edwards R, Baum M, Cawthorn S, Coates A, Hamed A, Howell A, Powles T; IBIS investigators. First results from the International Breast Cancer Intervention Study (IBIS-I): a randomised prevention trial. Lancet. 2002 Sep 14;360(9336):817-24. doi: 10.1016/s0140-6736(02)09962-2.
Warwick J, Pinney E, Warren RM, Duffy SW, Howell A, Wilson M, Cuzick J. Breast density and breast cancer risk factors in a high-risk population. Breast. 2003 Feb;12(1):10-6. doi: 10.1016/s0960-9776(02)00212-6.
Sestak I, Kealy R, Nikoloff M, Fontecha M, Forbes JF, Howell A, Cuzick J. Relationships between CYP2D6 phenotype, breast cancer and hot flushes in women at high risk of breast cancer receiving prophylactic tamoxifen: results from the IBIS-I trial. Br J Cancer. 2012 Jul 10;107(2):230-3. doi: 10.1038/bjc.2012.278. Epub 2012 Jun 26.
Palva T, Ranta H, Koivisto AM, Pylkkanen L, Cuzick J, Holli K. A double-blind placebo-controlled study to evaluate endometrial safety and gynaecological symptoms in women treated for up to 5 years with tamoxifen or placebo - a substudy for IBIS I Breast Cancer Prevention Trial. Eur J Cancer. 2013 Jan;49(1):45-51. doi: 10.1016/j.ejca.2012.06.015. Epub 2012 Jul 23.
Cuzick J, Sestak I, Cawthorn S, Hamed H, Holli K, Howell A, Forbes JF; IBIS-I Investigators. Tamoxifen for prevention of breast cancer: extended long-term follow-up of the IBIS-I breast cancer prevention trial. Lancet Oncol. 2015 Jan;16(1):67-75. doi: 10.1016/S1470-2045(14)71171-4. Epub 2014 Dec 11.
Brentnall AR, Cuzick J, Byers H, Segal C, Reuter C, Detre S, Sestak I, Howell A, Powles TJ, Newman WG, Dowsett M. Relationship of ZNF423 and CTSO with breast cancer risk in two randomised tamoxifen prevention trials. Breast Cancer Res Treat. 2016 Aug;158(3):591-6. doi: 10.1007/s10549-016-3885-x. Epub 2016 Jul 11.
Cuzick J, Brentnall AR, Segal C, Byers H, Reuter C, Detre S, Lopez-Knowles E, Sestak I, Howell A, Powles TJ, Newman WG, Dowsett M. Impact of a Panel of 88 Single Nucleotide Polymorphisms on the Risk of Breast Cancer in High-Risk Women: Results From Two Randomized Tamoxifen Prevention Trials. J Clin Oncol. 2017 Mar;35(7):743-750. doi: 10.1200/JCO.2016.69.8944. Epub 2016 Dec 28.
Smith SG, Sestak I, Howell A, Forbes J, Cuzick J. Participant-Reported Symptoms and Their Effect on Long-Term Adherence in the International Breast Cancer Intervention Study I (IBIS I). J Clin Oncol. 2017 Aug 10;35(23):2666-2673. doi: 10.1200/JCO.2016.71.7439. Epub 2017 Jun 29.
Other Identifiers
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2005-003091-38
Identifier Type: EUDRACT_NUMBER
Identifier Source: secondary_id
ISRCTN91879928
Identifier Type: REGISTRY
Identifier Source: secondary_id
CDR0000064151
Identifier Type: -
Identifier Source: org_study_id