A trial looking at celecoxib for women with breast cancer (REACT)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Breast cancer




Phase 3

This trial is looking to see if taking a Cox-2 inhibitor called celecoxib, after treatment helps to stop early breast cancer coming back in women.

Many breast cancers respond very well to treatment. But this is not always the case and sometimes breast cancer can come back. Doctors think that celecoxib might lower the risk of some cancers coming back. Celecoxib is a type of drug called a Cox-2 inhibitor. These are a type of anti inflammatory drug. They block a protein, called Cox-2, that may help cancers to grow.

The aim of this trial is to compare celecoxib to dummy tablets (placebo) for women with early breast cancer. The doctors want to find out whether celecoxib helps to stop breast cancer from coming back. And to find out more about the side effects of celecoxib.

Who can enter

You can enter this trial if you are female and you 

  • Have breast cancer that has been completely removed with surgery
  • Are currently having radiotherapy or finished radiotherapy within the last 6 weeks, OR had your surgery less than 3 months ago, OR finished chemotherapy between 3 weeks and 4 months ago
  • Are well enough to take part (performance status 0 or 1)
  • Have satisfactory blood test results
  • Are willing to use reliable contraception (apart from the pill) when taking part in the trial if there is any chance that you may become pregnant
  • Are at least 18 years old

If your breast cancer is NOT hormone sensitive, you must have had chemotherapy before you can take part in this trial

You cannot enter this trial if

  • Your breast cancer has not spread to your lymph nodes Open a glossary item AND your tumour is 2cm or less AND it is grade 1
  • Your doctors think you have a lower than average risk of your breast cancer coming back (your doctor will tell you more about this)
  • You have locally advanced or metastatic breast cancer
  • You have cancer in both breasts
  • Your breast cancer is HER2 positive (score of 3+)
  • You have been taking part in another clinical trial, and the doctor in charge of that trial has not given permission for you to take part in this trial
  • You have had any other cancer in the past 10 years (apart from non melanoma skin cancer, carcinoma in situ of the cervix, ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS)
  • You have other medical problems, such as a stomach ulcer, inflammatory bowel disease, heart problems, uncontrolled high blood pressure, insulin dependent diabetes, a stroke, heart attack , or osteoporosis that is causing you symptoms
  • You have taken hormone replacement therapy within the last 6 weeks
  • You are allergic to celecoxib, non steroid anti inflammatory drugs (NSAIDs), sulphonamides (a type of antibiotic) or salicylates (an ingredient in aspirin)
  • You have been taking anti inflammatory drugs for more than 6 weeks, or you plan to take them for more than 6 weeks in the future (you might be able to take part if you take a daily low dose of aspirin)
  • You are currently taking steroids, or you have taken them for a long time in the past
  • You are pregnant or breastfeeding

Trial design

This is a randomised trial. It will recruit 2,590 women into 2 groups. The people taking part are put into treatment groups by computer. Neither you, nor your doctor, will be able to decide which group you are in, or will be told which group you are in. This is called a double blind trial.

If you are in group 1, you will have celecoxib. If you are in group 2, you will have dummy tablets (placebo).

You will take either the placebo or the celecoxib tablets once a day for up to 2 years.

If you have hormone sensitive breast cancer you will also take hormone treatment. This will be prescribed by your consultant.

The researchers would like to look at a sample of your breast cancer that was kept by the doctors when you had your surgery. It will help the researchers learn more about breast cancer.

Hospital visits

You will see the doctors and have some tests before you can take part in the trial. These include

  • Heart trace (ECG)
  • Blood tests
  • Physical examination

You may also need to have another mammogram. Some women may need to have further tests to check that their cancer has not spread. These may include a CT scan, ultrasound scan and bone scan.

You will go to the hospital to see the doctors 

  • After 3 months, 6 months and 12 months in the first year, then
  • Every 6 months in the 2nd and 3rd year, then
  • Once a year for up to 10 years

You will have another heart trace (ECG) and blood test after one year, and when you stop taking the celecoxib or placebo.

Side effects

The most common side effects of celecoxib are

  • Stomach pains
  • Painful sinuses (sinusitis)
  • Rash

There may also be a small increase in risk of heart attack or stroke when taking celecoxib.

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 Charles Coombes

Supported by

Cancer Research UK
Experimental Cancer Medicine Centre (ECMC)
German Breast Group (GBG)
Imperial College London
NIHR Clinical Research Network: Cancer

Other information

This is Cancer Research UK trial number CRUKE/03/015.

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 464

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

Deborah wanted to help other breast cancer patients in the future

A picture of Deborah

“Deborah agreed to take part in a trial as she was keen to help other cancer patients in the future. "If taking part in a trial means others might be helped then I’m very happy with that."

Last reviewed:

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