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English Summary- IBIS-II-DCIS

This text is only available in German.


GBG 34: International Breast Cancer Intervention Study-II DCIS

An international multi-centre study of tamoxifen vs anastrozole in postmenopausal women with Ductal Carcinoma in Situ (DCIS)

 

Current Status: Closed

 

For further information please refer to: www.ibis-trials.org



Trial design:

A multicentre, randomised, double-blind, double-dummy clinical trial

Treatment:

Women will be randomised in a 2-arm design to receive one of the following treatments: tamoxifen 20mg + anastrozole placebo; anastrozole 1mg + tamoxifen placebo and all women will take 2 tablets/day for a period of 5 years

Patient population:

  1. All women must be postmenopausal and aged between 40-70 years. Postmenopausal status is defined as meeting one or more of the following criteria:
    a.  over the age of 60
    b.  bilateral oophorectomy
    c.  aged under 60 years with a uterus and amenorrhoea for at least 12 months
    d.  aged under 60 years without a uterus and with FSH >30 IU/L
  2. Locally excised DCIS diagnosed within the last 6 months.
  3. Oestrogen receptor or progesterone receptor (ER or PgR) status of DCIS must be known and must be greater than 5% positive cells
  4. A baseline bone mineral density scan within the last two years (DXA either of hip, lumbar spine or forearm) will be required for all women. A spinal x-ray to rule out fragility fractures will also be required in some cases.

Primary Objectives:

  1. To determine if anastrozole is at least as effective as tamoxifen in local control and prevention of contralateral disease in women with locally excised ER and/or PgR positive DCIS
  2. To compare side effect profiles of tamoxifen and anastrozole

Secondary Objectives:

  1. To compare the effectiveness of tamoxifen and anastrozole according to the receptor status of the primary or recurrent cancer
  2. To examine the rate of breast cancer recurrence and new contralateral tumours after cessation of tamoxifen or anastrozole.
  3. To examine the effect of tamoxifen vs anastrozole on breast cancer mortality.
  4. To examine the effect of tamoxifen and anastrozole on other cancers, cardiovascular disease, fracture rates, and non-breast cancer deaths
  5. To examine tolerability and acceptability of side effects experienced by women on the study

Primary Endpoint:

The primary endpoint is the development of histological confirmed breast cancer, both invasive and non-invasive (i.e. including new or recurrent DCIS). These will be separately categorised as local recurrence (all ipsilateral disease), distant recurrence or new contralateral tumour but the primary analysis will be based on all of them.

Addenda:

Trial protocol V7 20th March 2003 Amendment to the Trial protocol for Germany No. 2 Version 06.11.2003

Study Report:

IBIS-II (DCIS) is designed to continue the work started in IBIS-I in determining whether a chemopreventive strategy towards breast cancer is beneficial. IBIS-I was set up to investigate the use of tamoxifen as a preventive agent for women with moderate to increased risk of getting breast cancer. IBIS-2 DCIS will investigate which breast cancer treatment drug, anastrozole or tamoxifen, is better at preventing the disease from returning in women who have had an early type of breast cancer called Ductal carcinoma in situ (DCIS) and breast conserving surgery. Women who have had DCIS are at higher risk of getting cancer in the same breast and in the opposite breast as well as being more likely to develop more advanced forms of breast cancer.

Tamoxifen has been used as first line adjuvant treatment for breast cancer for over 20 years. Tamoxifen is a comparatively well tolerated drug with minimal reported side effects. Long-term results of a worldwide breast cancer prevention study - called IBIS-I - confirm that tamoxifen, a well established treatment for breast cancer, also reduces the risk of hormone receptor positive breast cancer by 34 per cent in women at increased risk of the disease, and that the effect continues for at least several years even after treatment with the drug has stopped. Anastrozole is a potent new non-steroidal aromatase inhibitor which is highly selective, well tolerated and effective in treating advanced breast cancer. Anastrozole does not possess progestogenic, androgenic or oestrogenic activity. Collection of tumor material and serum is ongoing.

  • Study Group: Cancer Research UK (CRUK), German Breast Group (GBG)
  • Study Chair: Prof. Dr. Wolfgang Eiermann
  • Clinical Project Management: Dr. Kai Büchsenschütz
  • Data Management / Biometry: Cancer Research UK in cooperation with GBG Forschungs GmbH
  • Study start: January 2003 (international), November 2003 (Germany)
  • Enrolment period: July 2004 - End 2011
  • Proposed accrual: International 4000 women, Germany 400 women
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