Expert: Claes-Gustaf Nordquist, M.D. - 12/22/2007

Question
hi, I emailed you a month or so ago about my friend who had a primary colon cancer removed(on the mid colon right hand side of the body as you look at it) and 7 lesions removed from the liver following a very good response to chemo (8 courses through the vain and also xeloda tablets).  She returned to the doctors 2 months after the liver resection with vaginal bleeding and a biopsy confirmed a bowel secondary.  My friend has since had a CT scan.  The doctor phoned today to say that nothing has shown up on the CT scan atall.  He explained that its rare to get a secondary here and arent sure what to do.  He has said that a PET scan will be necessary and this will probably follow with some high intensity radiotherapy.  When asked whether that would follow by an operation he said they dont know yet.  He did also mention that the CEA count had gone up to thirty whereas when the chemo had finished in March it was into single figures.

My questions are as follows if you could be so kind to help:

1.  Is it possible that if it is an isolated secondary as it seems, radiotherapy alone COULD kill the tumour and put her back into remission without any other treatment or would an operation be necessary to deem it curative.

2.Will it be more likely to show up on the PET scan than the CT.

3. Is radiotherapy more likely to work better on this tumour because of its position near the outside of the body. I have heard that Radiotherapy is not usually effective on colon cancers.  Is it that its less likely to work on a persons colon because it is deeper in the body or is it down to the type of cell a colon cancer is?

Lastly, She is actually putting on weight.  I was always under the impression that people lose weight when they get cancer.  Does this mean the cancer isnt too bad or is it possibly fluid build up?

I thank you for your responses so far - your help has been so valuable - although the doctors do a fantastic job my friend is sometimes wondering what to think and your replies help very much.  Do you have an opinion on my friends likely prognosis now we have a further spread?

Thanks

Answer
1. It is POSSIBLE that it is an isolated secondary but FAR from certain! Others may exist but too small to be noticed.
2. PET and CT are very different methods. PET is more (but not completely) specific for cancer, while CT shows EVERYTHING. CT has a higher resolution.  Best is if both are used together (AND MRI scans and ultrasound scans).
Personally I think a combination of chemo therapy, maybe radiation therapy and surgery would be best. If too much radiation has to be given surgery will no longer be possible. It impairs healing.
2. Depends, PET is more specific but CT can show smaller things.
3. Perhaps, but colon cancers are not usually very radiation sensitive as I have told you before. However the present position MAY mean that particle beams (most probably electrons, neutrons and heavy ions - if available - would probably be even better - as would protons or concentrated gamma rays (GammaKnife, CyberKnife) if the lesion is small enough) can be used and they would probably be somewhat more effective. Both factors are involved but colon cancer cells (except from the rectum) ARE less sensitive!
Well that depends on how advanced her cancer is. If not rather well advanced there are no such signs! But an increase in CEA is probably NOT a good sign!