Hello, my father was operated for stage 3 colon cancer about two wks back and now Dr. Is suggesting that he has to go through 6 mnths of chemo followed by radiotherapy if required. Now, I am really confused on following points:

1) whats the basis of determining that he needs chemo and its dosage?
Granted that in about 18inch of colon the Dr. Took out, the cancer seemed to reach the outer layer ( cirumfurance) of the rectum (ct scan showed no other organs are affected) but is that good enough to say that he needs chemo? Does anyone know of any tests which can be done right now to determine what % of cancer cells still left in nearby areas of colon? My father is on temp. Colostomy.

2) what if the cancer cells are cured after 3 mnths? What tests drs do in order to keep track of the progress?

My father is 68 and he is insisting that if he can live 8/10 years after this surgery, he dont really want to go through the difficult process of chemo/radio.

Any help is much appreciated.

Regards,
nks