A trial looking at the effect of exemestane and celecoxib on ductal carcinoma in situ (DCIS) (ERISAC trial)

Cancer type:

Breast cancer




Phase 3

This trial was trying to find out if 2 drugs called exemestane and celecoxib could help to treat ductal carcinoma in situ.

Ductal carcinoma in situ (DCIS) is a very early form of breast cancer. It means that some of the cells inside the ducts in your breast have started to turn into cancer cells. Some people call it ‘pre cancerous’ because if not treated it can develop into invasive breast cancer.

Doctors usually treat DCIS with surgery. And you may have a type of hormone therapy called tamoxifen to reduce the risk of developing an invasive breast cancer in the future.

But research has shown that tamoxifen does not work very well for some women with DCIS. Doctors thought that 2 other drugs might be useful for treating DCIS.

One was exemestane (Aromasin), a type of hormone therapy called an aromatase inhibitor. The other drug was celecoxib, a COX-2 inhibitor. COX-2 inhibitors block the action of a protein called COX-2 that may help cancer cells to grow.

In this trial, some women had exemestane and some had celecoxib. Some women didn’t have either drug, but had a dummy pill (placebo Open a glossary item). All the women took their tablets for 2 weeks, between being diagnosed with DCIS and having surgery to remove it.

The aim of this trial was to look at the cells removed during surgery to find out how the drugs had affected the DCIS cells.

Summary of results

Results from this trial showed that exemestane can affect DCIS, but celecoxib does not.

  • 90 women took part in this trial
  • 70% had DCIS that was ER and PR positive
  • 30% had DCIS that was ER positive, but PR negative

The researchers studied a protein called Ki67 that is present when cells are dividing and growing into new cells. They also looked at

  • The number of cells dying off (apoptosis Open a glossary item)
  • How much HER2 and COX-2 there was
  • The number of progesterone receptors

In women who took exemestane, there was less Ki67 in the tissue removed during surgery than there had been when they’d had a biopsy. This showed that fewer cells were dividing and growing into new cells. The number of progesterone receptors was also reduced in women who took exemestane.

In women who took celecoxib, the number of cells dividing or dying off did not change. And the amount of COX-2 found in the tissue did not seem to affect the number of cells dividing or dying off.

So, the researchers found that exemestane may help to treat ER positive DCIS. They suggest it should be studied further as an alternative to tamoxifen for preventing DCIS coming back or developing into invasive breast cancer.

We have based this summary on information from the team who ran the trial. As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item) or published in a medical journal yet. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Nigel Bundred

Supported by

Celecoxib Oncology Research in Europe (CORE)
National Institute for Health Research Cancer Research Network (NCRN)
University Hospital of South Manchester (UHSM)
University of Manchester

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle - 569

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

Picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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