Susan: I totally believe in the tumor markers. After my initial treatment 4 yrs ago, my CEA was at 12 and remained there. I was seeing my onco every 3 mos. W/in a 3 mo period, my CEA jumped from 12-39. We immediately starting running tests...bone marrow, ct scan, MRI and finally a PET scan. On the PET scan, a very small area showed up. If it hadn't been for the tumor markers, I don't know if we would have caught it early. Keep track. Be proactive.