chemo or not

[hopeful85]

I was diagnosed with stage IV colorectal cancer 11/1/06.  Surgical resection successful.  8 months chemotherapy.  last chemo treatment was 9/5/07.  CEA below 3.0 from 9/19/07 - 1/28/08.  Started rising sharply: 13.4 on 2/29/08; 33.1 on 3/19/08; 92 on 4/14/08; 244.8 on 5/12/08.  CT on 3/25/08 and PET on 4/8/08 scans negative .  My oncologist has been encouraging me to get back onto a chemotherapy regimen.  How high should I let CEA go before returning to chemo?  Shouldn't results of CT help me determine whether to return to chemo or not at this time?  I note on MD Anderson Cace Center Guidelines for Colon Cancer "individualized surveillance" is recommended (61 years old, working, feel good).

[hopeful85]

Dear Dr. Rogue,
Thank you very much for your thorough reply.  I will know latest CEA on 5/30/08.  Unless numbers are lower, I will proceed with chemotherapy scheduled for 6/2/08.  I will also ask my oncologist for another CT, since the last was two months ago, especially if all areas were not included.
hopeful85

[Fernando Roque, MD]

Hi.  The fact that you have been previously diagnosed with Stage IV colorectal cancer make persistent elevations in carcinoembryonic antigen (CEA) highly suggestive of recurrent disease.  A CEA value persistently greater than 5.0 is already abnormal, and should already prompt a thorough work-up for recurrence.  The higher the value of the CEA, the higher is the probability of the presence of metastases/ recurrent disease.  

The increasing trend of your CEA levels would make the possibility of cancer relapse highly likely.  The problem is, no masses have been seen on repeat CT and PET.  One possible explanation for this may be that the work-up is still incomplete.  Was a CT scan of the chest, abdomen, and pelvis done? Was a repeat colonoscopy performed?  If you missed out on any of the tests I mentioned, I think you should have them done.  

Now, if all the imaging studies have been completed and everything turns up negative, the National Comprehensive Cancer Network (NCCN) guidelines recommend that "repeat CT scans are indicated every 3 months" in the face of persistently elevated CEA.  However, your oncologist's opinion to have chemotherapy again is still a valid recommendation, in light of a CEA level of 244.8.  So it really depends on how aggressive you want to be with your treatment.