Colofol - Evaluation of the frequency of a surveillance program
Colofol, participating countries: Denmark, Sweden, Poland, Ireland and Uruguay
Layperson Protocol
Next Colofol meeting
Data Entry
The trial includes bloodtests and CT-scans of the liver and lungs


The scientific investigation COLOFOL:
The Interval beween control-examinations after operation for colorectal cancer.

We know some patients will experience recurrent disease, despite all malignant tissue apparently were removed at the operation. It is although uncertain whether you by means of hospital control investigations can diagnose these recurrencies before symptoms occur thus improving the chance of cure. The guidelines for which kind of control programmes to apply after the operation are thus variable from hospital to hospital.

During the later years better scanning methods have become available, and it is possible, that these methods can improve the control programmes. We do not know and we also do not know how often the controls are to be performed. We can only get an answer on this through a randomised study where the interval between controls are descided by the draw of a lot.

The advantage by a frequent control is that a recurrence eventually can be discovered in such a due time that cure is possible. The disadvantage is that some patients dislike frequent visits to hospitals, and sometime you find something which finally shoes up to be non recurrent disease. The control investigations might not find the recurrence if it is very small. The advantage by a less frequent control is that you are not reminded of the malignant disease, you have been operated for. The disadvantage is that the possibilities for cure might be less if treatment is postponed until symptoms occur.

We therefore ask whether you will participate in our trial. You are welcome to bring consult relatives and as an addition to this letter, you find the brochure "Before I Decide". We want to emphasize, that your decision will have no influence on your treatment and control. If you accept, it is your right to withdraw your consent at any time without this will have any influence on your treatment. If you say no, you will be offered control according to the normal procedures in the department. We are not able to offer you frequent control outside the trial. This programme is expensive, and we do not know whether it works, thus we have give priority according to our resources

A lot wil be drawn in frequent control: 6, 12, 18, 24 and 36 months after the operation a CT-scan or X-ray of the lungs, a CT-scan of the abdomen, and a blood sample will be performed. In the group of infrequent control the same investigations will be performed at 12 and 36 months after the operation

By frequent CT-scan you will be exposed to an elevated, but still very small dose of radiation (about 10 millisievert, which is double the dose, you normally get from the environment per year). The risk this dose should lead to cancer is betwen 1:3000 to 1:16,000. The risk an average person develops cancer during his/her lifetime is about 1:4.

The trial is called COLOFOL and has been supported by the Nordic Cancer Union. No individual persons or companies has any economic interests in the trial, which is conducted in several European Countries.