### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Hi, my name is Gary I was diagnoses and had colon cancer stage 4 and spread to liver. I had treatment 5 weeks for radiation, and  total 6 times chemo. It seem like first 3 times chemo therapy is not working so my doctor change to different chemo medicine, is seem like cancer wont spread and shrunk. by that time i met some one and he recommend me to change my diet, drink more water, no sugar, so when i went to draw blood my CEA went up from 24 to 30 and after i change my diet and last 3 chemo my CEA back down to 13 and my doctor told me i have to do one more chemo. And i decided not to do because a lot of people told me radiation and chemo kill people more than cancer kill people. So i went back to draw blood and check with my doctor my CEA go back up to 26.     I would like to know am i do the right thing? just only change my diet and not listen what my doctor tell me what to do??? right now i feel just like normal person, i can go to exercise, running, walking, but i lot some weight  because i eat only fish, vegetable, and fruit.would you please, answer me what am i suppose to do?? Thank you so muchGary

### output:

Hi, I went through your query. I am afraid changing your diet at this stage will not cure your cancer. Colon cancer mainly occurs due to a high fat diet. Dietary fiber as in fruits and vegetables has a protective role. However once you have the cancer it does not help much. It is true that chemotherapy and radiation have very serious side effects and can themselves cause cancer. But at stage 4 that is the best possible treatment available. I would advise you to continue with your treatment. But you can talk to your doctor if you do not wish it and ask him/her for some other palliative treatment. Hope this helps.