ABCSG 15/IBIS II Details

An international multi-centre study of tamoxifen vs anastrozole in postmenopausal women with ductal carcinoma in situ (DCIS)

Contact ABCSG-Trial office

Phone: +43 1 408 92 30
Fax: +43 1 409 09 90


ABCSG-15 Design
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Primary objectives:

  • 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+ve DCIS.

Secondary objectives:

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

Inclusion criteria:

  1. All women must be postmenopausal and between ages of 40-70. Postmenopausal status is defined as meeting one or more of the following criteria:
    • Over the age of 60
    • Bilateral oophorectomy
    • Aged ≤60 with an uterus and amenorrhoea for at least 12 months
    • Aged ≤ 60 without an uterus and with FSH > 30 lU/L
  2. Locally excised DCIS diagnosed within the last 6 months. Oestrogen receptor or progesterone receptor (ER or PgR) status of DCIS must be known and must be greater than 5% positive cells
  3. A baseline bone mineral density scan within the last two years (DXA either of hip, limbar spine or forearm) will be required for all women. A spinal x-ray to rule out fragility fractures will also be required.
  4. Fully informed signed consent must have been obtained.

Exclusion criteria:

  1. Premenopausal women
  2. Any previous cancer in the past 5 years (except non-melanoma skin cancer or in situ cancer oft he cervix)
  3. Current treatment with anti-coagulants
  4. Previous deep vein thrombosis or pulmonary embolus
  5. Previous transient ischaemic attack (TIA) or cerebrovascular accident (CVA, stroke)
  6. Current or previous tamoxifen or raloxifene or other SERMs use for more than 3 months or participation in IBIS-I
  7. Intention to continue to use oestrogen-based hormone replacement therapy
  8. Women who have either had a prophylactic mastectomy o rare planning to have this procedure
  9. Any woman with unexplained postmenopausal bleeding
  10. Evidence of osteoporosis or fragility fractures within the spine. However, these women may be eligible if their T-score is more than minus four and they have no more than two fragility fractures. In either case they must take bisphosphonate treatment and have regular DXA scans. The results oft he scans must be provided to the trial, as for women in the IBIS-II Prevention bone sub-protocol. Women with T-scores of less than minus four or with more than two fragility fractures are not eligible.
  11. Any severe concomitant disease that would, in the opinion oft he investigator, place the woman at unusual risk or confound the results of the study.
  12. Life expectancy of less than 10 years or other medical condition which would significantly interfere with the ability to accept the chemopreventive treatments
  13. Psychologically and physically unsuitable for five years anti-oestrogen therapy
  14. Treatment with non-approved or experimental drug during the 3 months before randomisation