Big increase in CEA

Scubadan here after a little time off for vacation which included a great scuba diving trip in the Cayman Is. I took 2 wks off the Erbitux/Irinotecan infusions for the trip.  A couple of months ago my PET scan showed negative activity in all the small tumors and 2 lymphnodes, and only one liver tumor left that was smaller and less active. Great news.  My CEAs after the change to Erbitux indicated a reduction from 81 to 42.  Next CEA was 62, then the next was 64.  These are 1 mo apart.  After my return from vacation and back on infusions last week my CEA jumped to a whopping 237. I haven't talked to my onc about it yet since I just got the new CEA result yesterday during infusion. I've only found one article on the net that mentions that an elevated CEA can be caused by tumor reduction releasing lots of CEA.  All the others sites only indicate advancement of disease process. My next PET is on 9/11 (I'm not supersticious, but that date is outstanding for bad news) so I'm in limbo now as to asking the onc or waiting for the PET report. I'm just not sure if the onc's determination of the high CEA will be as definitive as the PET which have been so reliable for my case over the last 5 yrs. Whatever the High CEA means i"ll take it in stride as I have from the beginning of this ordeal and keep living my life as though I don't have anything wrong with me. A few concessions, yes, but overall I wake up each day and live for this day and not tomorrow or the past. Thank God I still feel good and can work 40 hrs a week and do my yard work during days off, and have a fully supportive wife of 41 yrs.