A trial looking at surgery and chemotherapy for advanced bowel cancer (ISAAC)

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

Cancer type:

Bowel (colorectal) cancer
Colon cancer
Rectal cancer




Phase 2/3

This trial is looking at removing the original (primary) area of cancer in the bowel or back passage before chemotherapy. It is recruiting people with advanced bowel cancer. This trial is supported by Cancer Research UK.

Doctors usually treat bowel cancer that has spread (metastasised) with chemotherapy. But if the original (primary) cancer starts to cause symptoms, such as pain or sickness, you may need an operation to remove it.

Symptoms can sometimes start during or after chemotherapy. The doctors in this trial think that it might be useful to remove the area of primary bowel cancer before it causes symptoms and before chemotherapy. But they are not sure yet. It is important to find out because doctors do not want to put people through unnecessary surgery.

The aims of this trial are to find out

  • If you have a bowel cancer that has spread, whether it is better to remove your original bowel cancer before having chemotherapy or wait to see if the cancer causes symptoms before removing it
  • More about side effects
  • More about quality of life

Who can enter

You can enter this trial if

  • You have advanced bowel cancer
  • The original (primary) cancer in the bowel area does not need to be removed straight away with an operation– your doctor can tell you more about this
  • Your cancer has spread and these areas of cancer cannot be removed with an operation
  • You are well enough to take part (performance status 0, 1 or 2)
  • You are willing to use reliable contraception if there is any chance that you or your partner could become pregnant
  • You have satisfactory blood and urine test results
  • You are at least 18 years old

You cannot enter this trial if

  • The original (primary) cancer in your bowel area cannot be removed with an operation
  • Your cancer has spread into a large area of your abdomen (peritoneum Open a glossary item)
  • You have had another cancer apart from non melanoma skin cancer or cervical carcinoma in situ
  • You have a serious medical condition that may prevent you from taking part
  • You are pregnant or breastfeeding

Trial design

500 people will take part in this trial. This is a randomised trial. The people taking part will be put into 2 different groups by computer. Neither you nor your doctor can decide which group you are in.

If you are in group 1 you have standard chemotherapy for advanced bowel cancer. If your primary bowel cancer causes symptoms and you are already taking part in the trial, then you may go on to have surgery if your doctors think it may help you.

If you are in group 2 you have surgery to remove your original area of bowel cancer. You will start standard chemotherapy for advanced bowel cancer 8 weeks later.

The type of standard chemotherapy you have in this trial depends on the hospital you go to. Your trial doctor will be able to tell you more about this.

You fill out a short questionnaire

  • When you join the trial
  • 8 weeks after you have surgery or begin chemotherapy
  • 3 months after joining the trial
  • 6 months after joining the trial
  • 6 months after surgery if you are in the surgery group

The questionnaire will ask about how you have been feeling. It is called a quality of life questionnaire.

As part of the trial, the researchers will ask your permission to get a sample of tissue that was removed when you had a biopsy. And they will ask if they can keep another sample of tissue if you have bowel surgery. The samples will be stored safely and may be used in the future, but only for research purposes. If you do not want to give these samples for research, you don’t have to. You can still take part in the trial.

Hospital visits

You see the doctors and have some tests before you start treatment. The tests include

  • Blood tests
  • CT scan of your liver and the original (primary) area of bowel cancer

If you have surgery you will probably be in hospital for between 1 and 3 weeks. You will also need a few weeks to recover from the operation.

When you finish treatment you will go to the hospital for routine check ups with your doctor every 3 months, for up to up to 2 years.

Side effects

All treatments have side effects. The most common side effects of chemotherapy include

The most common side effects of bowel surgery include

  • Blockage in the bowel (bowel obstruction)
  • Wound infection
  • Pain or swelling in the leg caused by a blood clot
  • Sudden chest pain or breathlessness caused by a blood clot

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

Mr Austin Obichere

Supported by

Cancer Research UK
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer

Other information

This is Cancer Research UK trial number CRUK/08/038.

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 3354

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

Cara took part in a clinical trial

A picture of Cara

"I am glad that taking part in a trial might help others on their own cancer journey.”

Last reviewed:

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