Clinical trial · Interventional
PROACT - Pre-Operative Arimidex Compared To Tamoxifen
A Randomised, Double-blind, Study Comparing ARIMIDEX™ With NOLVADEX™ as Neo-adjuvant and Adjuvant Treatment in Post-menopausal Women With Large Operable (T2 (≥3cm), T3, N0-2, M0) or Potentially-operable, Locally Advanced (T4b, N0-2, M0), ER+ and/or PR+ Breast Cancer.
- 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)
The purpose of this study is to compare tamoxifen, versus a newer treatment, ARIMIDEX, which we already know to be well tolerated. The main objectives of this research study are to see whether using these drugs will shrink down tumours before surgery and to see if any shrinkage in the tumour affects the extent of surgery that is required.
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 |
|---|---|---|---|
| ARIMIDEX (anastrazole) | Drug | Anastrozole | ALIAS |
| NOLVADEX (tamoxifen) | Drug | Tamoxifen | ALIAS |
Design
Arms and outcomes
Arms (0)
[]Primary outcomes (1)
- measure
- Objective tumour response
- timeFrame
- Assessed at 3 months
Secondary outcomes (10)
- measure
- Pathological response
- timeFrame
- Assessed at 3 months
- measure
- Extent of breast surgery
- timeFrame
- Assessed at 3 months
- measure
- Extent of axillary down-staging
- timeFrame
- Assessed at 3 months
- measure
- Clinical ultrasound response versus clinical caliper response
- timeFrame
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 60 Years
Show eligibility criteria text
Inclusion Criteria: * Operable or potentially operable breast cancer * Invasive breast cancer proven to be hormone-sensitive (ER+/PR+) * Patients who might benefit from endocrine treatment prior to surgery * Postmenopausal * Signed written informed consent Exclusion Criteria: * Inoperable breast cancer * Patient unwilling to undergo surgery * Any reason why the patient may not be able to conform to study requirements * Any previous treatment for breast cancer * Previous Tamoxifen use as a part of breast cancer prevention trials * Not willing to stop taking drugs that affect sex-hormones such as HRT * Previous history of breast cancer * Previous history of invasive malignancy within the last 10 years * Any other severe disease that may prevent surgery, place the patient at risk, or influence the study results * Treatment with an experimental drug within the last 3 months * Risk of transmitting HIV, Hepatitis B or C
References
Publications (2)
- RESULTCataliotti L, Buzdar AU, Noguchi S, Bines J, Takatsuka Y, Petrakova K, Dube P, de Oliveira CT. Comparison of anastrozole versus tamoxifen as preoperative therapy in postmenopausal women with hormone receptor-positive breast cancer: the Pre-Operative "Arimidex" Compared to Tamoxifen (PROACT) trial. Cancer. 2006 May 15;106(10):2095-103. doi: 10.1002/cncr.21872. PMID 16598749
- DERIVEDFujiwara Y, Takatsuka Y, Imoto S, Inaji H, Ikeda T, Akiyama F, Tamura M, Miyoshi K, Iwata H, Mitsuyama S, Noguchi S. Outcomes of Japanese breast cancer patients treated with pre-operative and post-operative anastrozole or tamoxifen. Cancer Sci. 2012 Mar;103(3):491-6. doi: 10.1111/j.1349-7006.2011.02171.x. Epub 2012 Jan 13. PMID 22136317