I've had colon cancer, had the surgery but didn't need chemo. I spent 5 years getting CEAs and as long as you don't smoke (IIRC) being below 5 is good but check with your doc. It can go up and down just because at the low end it tends to not be accurate. Above, I think 2.5, you should pay attention. At 5-10 you ought to get it checked with a full colonoscopy - at least I would.

I just had one again today, came back at 1.5 and that's normal. That said, I'm getting a colonoscopy this fall just because it's been 3 years since my last one. They are no big deal especially when you consider the alternative.... The really good news is that colon cancer caught early is very treatable (been there, done that).

Good luck! and don't worry until you know something.

J.