A trial looking at the best time for surgery after treatment for rectal cancer

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

Cancer type:

Bowel (colorectal) cancer

Rectal cancer

Status:

Closed

Phase:

Phase 2

This trial is to find out the best time to have surgery after having radiotherapy, or chemoradiation, for cancer of the back passage (rectum).

Doctors often treat rectal cancer with radiotherapy, or a combination of chemotherapy and radiotherapy (chemoradiation), before surgery. This is to shrink the cancer. After the treatment has worked, about 6 to 8 weeks later, they operate to remove the remaining cancer.

We know from research that radiotherapy and chemoradiation may carry on working for longer than 6 to 8 weeks. So the cancer could get smaller if we waited a bit longer. If this happens then people could have a smaller operation. But the researchers are not sure how long after they can wait to get the best results from the radiotherapy or chemoradiation.

The aim of this trial is to compare the size of the cancer

6 weeks after finishing radiotherapy or chemoradiation
12 weeks after finishing radiotherapy or chemoradiation

Who can enter

You can enter this trial if

You have the most common type of rectal cancer (adenocarcinoma)
You have completed treatment with radiotherapy or combined chemotherapy and radiotherapy (chemoradiation)
Your doctors have planned for you to have surgery to remove your cancer after your radiotherapy or chemoradiation
You are at least 18 years old

You cannot enter this trial if you

Are not being treated with radiotherapy or combined chemotherapy and radiotherapy (chemoradiation) before surgery to remove your cancer
Cannot have either an MRI scan or PET-CT scan – for example if you have a pacemaker or poorly controlled diabetes
Have another medical condition that could affect you taking part in this trial

Trial design

This trial will recruit 218 people. Everyone taking part in this trial will have radiotherapy, or chemoradiation, before surgery.

It is a randomised trial. You will be put into a 1 of 2 groups by a computer. Neither you nor your doctor can choose which group you are in. The 2 groups are

Surgery 6 weeks after radiotherapy, or chemoradiation
Surgery 12 weeks after radiotherapy, chemoradiation

Hospital visits

Before having radiotherapy or chemoradiation, everyone will have an MRI scan and another 6 weeks after completing their treatment. This is standard care. Where available you will also have a PET scan at these times as part of the study.

If you are in the 6 weeks group, you then have surgery.

If you are in the 12 weeks group and the 6 week scan shows your cancer has continued to grow you then have surgery.

If you are in the 12 weeks group and the 6 week scan shows your cancer has not grown, you have another scan after another 4 weeks and then surgery 2 weeks later.

After surgery you will attend follow up appointments in the out patients clinic in the usual way. You will have an appointment with the trial team once a year for 5 years, so they can see how you are.

Side effects

If you have surgery 12 weeks after radiotherapy or chemoradiation, there is a small chance that your cancer may start to grow again while you are waiting. Your doctor will look at a scan of your cancer 6 weeks after your radiotherapy or chemoradiation. If your doctor is at all concerned, he or she will discuss earlier surgery with you.

There is a small amount of radioactivity in the tracer injection for the PET-CT scan. But this shouldn’t cause any side effects or lasting effects.

You can find more about radiotherapy, chemoradiation, surgery for rectal cancer and PET-CT scan on CancerHelp UK.