IBIS II breast cancer trial

This page tells you about the IBIS II (IBIS 2) trial for breast cancer. This trial is following on from the IBIS I (IBIS 1) prevention trial. There is information about

• What the trial is about
• Who is taking part in this trial?
• When will we know the results of the trial?

The IBIS 1 prevention trial looked into using a hormone therapy called tamoxifen to prevent breast cancer in women at high risk of getting the disease. This trial found that the number of breast cancer cases was lowered by a third in the group of women taking tamoxifen. IBIS 2 is looking at using another hormone treatment – anastrozole.

There are two main parts to the IBIS 2 trial.

• IBIS 2 (prevention) is looking at preventing breast cancer.
• IBIS 2 (DCIS) is looking at treating DCIS

This page is about the IBIS 2 (prevention) trial, which is testing anastrazole to see if it can prevent breast cancer in women who are at high risk of getting this disease. We also have information about IBIS 2 (DCIS) on our clinical trials database. Both studies now have all the women they need and have closed to recruitment. So it is no longer possible to join. The researchers will continue to follow up the women on these trials for a number of years.

The women who are taking part in this trial have an increased risk of developing breast cancer. This is generally because they have a family history of breast or ovarian cancer. Other entry criteria included having had LCIS or DCIS in the past or a breast biopsy showing atypical ductal or lobular hyperplasia. The women are aged between 40 and 70 and are post menopausal.

This trial stopped recruiting women in January 2012. The researchers will be following the women for a few years yet. So it will be some time before we know if anastrozole can help prevent breast cancer in women at high risk of developing the disease.