Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Mr Mark Webster-Smith


Contact details

Clinical Trials & Statistics Unit (ICR-CTSU)
Section of Clinical Trials
Brookes Lawley Building
15 Cotswold Road
United Kingdom

Additional identifiers

EudraCT number

2004-000166-13 number


Protocol/serial number


Study information

Scientific title

A multicentre randomised interventional trial on the benefits of ovarian function suppression in pre-menopausal women with oestrogen receptor positive breast cancer



Study hypothesis

Chemotherapy (CT), tamoxifen, and ovarian function suppression (OFS) are individually effective adjuvant treatment modalities in women under 50 with oestrogen receptor (ER) positive (tumours expressing the oestrogen receptor) breast cancer. Chemotherapy plus 5 years tamoxifen (a widely used treatment which blocks the action of oestrogen on the tumour) is more effective than chemotherapy alone, however it is unclear whether any additional benefit is derived from ovarian function suppression as no trial has addressed this question to date.

This trial aims to focus the OFS question on the subset of women who biologically would be most likely to benefit. These are women with oestrogen receptor positive breast cancer who remain pre-menopausal following either surgery alone or after completion of chemotherapy. The majority of pre-menopausal women with breast cancer are at least 40, and more than 80% will develop amenorrhoea following 6 cycles of cyclophosphamide, methotrexate and fluorouracil 5FU (CMF) chemotherapy. By contrast, less than half of pre-menopausal women under the age of 40 develop amenorrhoea with CMF. The prognosis of women who develop amenorrhoea tends to be better than those who continue to menstruate. Consequently the women in this trial will generally be younger than the median age for pre-menopausal breast cancer and will most likely be under 40.

Ethics approval

South West Multi-centre Research Ethics Committee approved on the 4th August 2004 (ref: 04/Q1605/20)

Study design

Multicentre randomised interventional treatment trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

GP practices

Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Topic: National Cancer Research Network; Subtopic: Breast Cancer; Disease: Breast


1. Tamoxifen for 5 years
2. OFS** plus tamoxifen for 5 years
3. OFS** plus exemestane for 5 years
(** OFS = ovarian function suppression (triptorelin for 5 years OR surgical oophorectomy OR ovarian irradiation))

Radiation therapy to the conserved breast is required. Radiation therapy to the chest wall following mastectomy is optional (if given, it may also include nodal fields). Radiation therapy may be given either after all chemotherapy or integrated into chemotherapy.

Follow up length: 120 months
Study entry: registration and one or more randomisations

Intervention type



Phase III

Drug names

Tamoxifen, exemestane, triptorelin

Primary outcome measure

To compare ovarian function suppression (OFS: GnRH analogue or oophorectomy)

Secondary outcome measures

1. Overall survival
2. Systemic disease-free survival
3. Quality of life
4. Sites of first treatment failure

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Pre-menopausal women (estradiol [E2] levels in the pre-menopausal range) either after chemotherapy or without chemotherapy
2. Randomisation within an 8-month evaluation period after end of CT, or within 12 weeks after definitive surgery for patients with no CT. Patients with temporary chemotherapy-induced amenorrhoea who regain pre-menopausal status within 6 months of the final chemotherapy dose are eligible.
3. Histologically proven, resected breast cancer. Pathology material available for submission for central review.
4. Hormone receptor (HR) positive tumour. HR must be determined using immunohistochemistry (IHC): ER and/or progesterone receptor (PgR) greater than or equal to 10%
5. Tumour confined to the breast and axillary nodes without detected metastases elsewhere with the exception of tumour detected in the internal mammary chain nodes by sentinel node procedure
6. Proper surgery (total mastectomy or breast conserving procedure plus radiation) for primary disease with no known clinical residual disease
7. Axillary lymph node dissection or negative axillary sent

Participant type


Age group




Target number of participants

Planned sample size: 3000

Participant exclusion criteria

1. Post-menopausal
2. Distant metastatic disease
3. Locally advanced inoperable breast cancer
4. Bilateral invasive breast cancer
5. Positive final margins
6. Clinically detectable residual axillary disease
7. History of previous ipsilateral or contralateral invasive breast cancer
8. Previous or concomitant malignancy except adequately treated basal/squamous cell carcinoma of the skin, in-situ carcinoma of the cervix or bladder, contralateral or ipsilateral in-situ breast cancer
9. Other non-malignant systemic diseases that would prevent prolonged follow-up
10. Patients who have had a bilateral oophorectomy or ovarian irradiation or are planning oophorectomy within 5 years
11. History of noncompliance to medical regimens or considered potentially unreliable
12. Patients who are pregnant or lactating at randomisation or who desire a pregnancy within 5 years. Patients planning to use additional hormone therapy (including contraceptives) during the next 5 years
13. Previous endocrine therapy (neoadjuvant/adjuvant)

Recruitment start date


Recruitment end date



Countries of recruitment

Australia, Belgium, Canada, Egypt, Germany, Hungary, India, Italy, New Zealand, Peru, Slovenia, South Africa, Sweden, Switzerland, United Kingdom, United States of America

Trial participating centre

Clinical Trials & Statistics Unit (ICR-CTSU)
United Kingdom

Sponsor information


European Institute of Oncology (IEO) (Italy)

Sponsor details

Via Ripamonti 435

Sponsor type

Research organisation



Funder type


Funder name

Cancer Research UK (CRUK) (UK) (ref: C2232/A4595)

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

other non-profit


United Kingdom

Funder name

International Breast Cancer Study Group (IBCSG) (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

19/10/2018: Cancer Research UK lay results summary link added to Results (plain English) 08/04/2016: No publications found, verifying study status with principal investigator.