Clinical trial · Interventional
Adjuvant Tamoxifen Compared With Anastrozole in Treating Postmenopausal Women With Ductal Carcinoma In Situ
International Breast Cancer Intervention Study II (IBIS-II) (DCIS)
NCT00072462CI-TRIAL-00080639IBIS-II DCIScompletedPhase 3Results postedClinicalTrials.gov clinicaltrialsProvenance
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using either tamoxifen or anastrozole may fight breast cancer by blocking the use of estrogen. It is not yet known whether tamoxifen is more effective than anastrozole in preventing breast cancer after surgery for ductal carcinoma in situ. PURPOSE: This randomized phase III trial is studying how well adjuvant tamoxifen works compared to anastrozole in treating postmenopausal women who have undergone surgery to remove ductal carcinoma in situ.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Cancer | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
Interventions
Interventions (2)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Anastrozole | Drug | Anastrozole | ALIAS |
| tamoxifen citrate | Drug | Tamoxifen | ALIAS |
Design
Arms and outcomes
Arms (2)
- type
- ACTIVE_COMPARATOR
- label
- Anastrozole
- interventionNames
- Drug: Anastrozole
- type
- ACTIVE_COMPARATOR
- label
- Tamoxifen
- interventionNames
- Drug: tamoxifen citrate
Primary outcomes (1)
- measure
- Number of Participants With Breast Cancer Recurrence, Including Recurrent DCIS and New Contralateral Tumours
- timeFrame
- Date of the breast cancer occurrence is defined as the date of the confirmation of the specific event (from randomisation to date of occurrence). Data presented is from randomisation to study completion, median follow-up was 11.6 years (IQR: 9.9-13.5).
Secondary outcomes (4)
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 40 Years
- Maximum age
- 70 Years
Show eligibility criteria text
DISEASE CHARACTERISTICS:
* Diagnosis of ductal carcinoma in situ within the past 6 months
* Locally excised with tumor-free margins at least 1 mm
* Hormone receptor status:
* Estrogen or progesterone receptor positive
* Equal to or greater than 5% positive cells
PATIENT CHARACTERISTICS:
Age
* 40 to 70
Sex
* Female
Menopausal status
* Postmenopausal, defined as meeting at least 1 of the following criteria:
* Over age 60
* Prior bilateral oophorectomy
* Age 60 or under with a uterus AND amenorrhea for at least the past 12 months
* Age 60 or under without a uterus AND follicle-stimulating hormone greater than 20 IU/L
Performance status
* Not specified
Life expectancy
* At least 10 years
Hematopoietic
* Not specified
Hepatic
* Not specified
Renal
* Not specified
Cardiovascular
* No prior deep vein thrombosis
* No prior transient ischemic attack
* No prior cerebrovascular accident
Pulmonary
* No prior pulmonary embolism
Other
* No unexplained postmenopausal bleeding
* No other cancer within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix
* No other concurrent medical condition that would preclude study therapy, place the patient at unusual risk, or confound study results
* No evidence of osteoporosis
* Fragility fractures within the spine allowed if T-score level is greater than -4 and consist of no more than 2 fractures
* Psychologically and physically suitable for 5 years of study therapy
PRIOR CONCURRENT THERAPY:
Biologic therapy
* Not specified
Chemotherapy
* Not specified
Endocrine therapy
* No prior or concurrent tamoxifen use lasting more than 6 months unless treatment was completed more than 5 years ago. Women in IBIS-I can join if off trial therapy for at least 5 years.
* No prior or concurrent raloxifene use lasting more than 6 months unless treatment was completed more than 5 years ago.
* No other prior or concurrent selective estrogen-receptor modulator use lasting more than 6 months unless treatment was completed more than 5 years ago
* No concurrent systemic estrogen-based hormone replacement therapy, including vaginal estrogen preparations
Radiotherapy
* Not specified
Surgery
* See Disease Characteristics
* No prior mastectomy
* No planned prophylactic mastectomy
Other
* At least 3 months since prior unapproved or experimental agents
* No concurrent anticoagulantsReferences
Publications (3)
- BACKGROUNDJuraskova I, Butow P, Lopez A, Seccombe M, Coates A, Boyle F, McCarthy N, Reaby L, Forbes JF. Improving informed consent: pilot of a decision aid for women invited to participate in a breast cancer prevention trial (IBIS-II DCIS). Health Expect. 2008 Sep;11(3):252-62. doi: 10.1111/j.1369-7625.2008.00498.x. PMID 18816321
- BACKGROUNDForbes JF, Sestak I, Howell A, Bonanni B, Bundred N, Levy C, von Minckwitz G, Eiermann W, Neven P, Stierer M, Holcombe C, Coleman RE, Jones L, Ellis I, Cuzick J; IBIS-II investigators. Anastrozole versus tamoxifen for the prevention of locoregional and contralateral breast cancer in postmenopausal women with locally excised ductal carcinoma in situ (IBIS-II DCIS): a double-blind, randomised controlled trial. Lancet. 2016 Feb 27;387(10021):866-73. doi: 10.1016/S0140-6736(15)01129-0. Epub 2015 Dec 11. PMID 26686313
- BACKGROUNDSestak I, Smith SG, Howell A, Forbes JF, Cuzick J. Early participant-reported symptoms as predictors of adherence to anastrozole in the International Breast Cancer Intervention Studies II. Ann Oncol. 2018 Feb 1;29(2):504-509. doi: 10.1093/annonc/mdx713. PMID 29126161