Except in my case, without exception, I have always and only experienced elevated CEA levels when tumor activity was present. Specifically in my liver. See this chart of my lifetime CEA levels.

- Initial colon cancer presentation
- First metastatic presentation, a single-focus, single-site tumor in my left lung
- Second metastatic presentation, a single-focus, single-site tumor in my liver
- Third metastatic presentation, single-focus, multi-site tumors in my liver
- Fourth metastatic presentation, addition tumor in my liver while on pre-operative chemotherapy for third presentation
- Fifth metastatic presentation, multi-focus, multi-site tumors in my diaphragm and omentum
- Current state of elevated CEA levels, but no diagnostic medical imaging yet
When I first presented with my primary colon cancer in April of 2008, my CEA levels were 0.2 to 0.3. When I presented with the metastatic tumor in my left lung in April of 2009, my CEA levels were 0.7. But when I started presenting liver metastases, they shot up. Every time I've presented a liver metastasis, my CEA levels have been elevated. Right now they are higher than they were last summer when I had three metastatic tumors in my liver growing with a four-week doubling rate.
In other words, while checking my CEA levels can produce a false negative, i.e., low CEA levels while I have an active tumor, it has not ever produced a false positive, i.e., elevated CEA levels with no corresponding active tumor.
Hence my deep sense of dread now. Despite years of dealing with this, despite gaining a lot of ground with acceptance in my own begrudging way, despite knowing the implications of the January findings and being formally classed as incurable, this is still a horrifying shock.
I have a number of thoughts about treatment paths, lifestyle issues and mortality, but they're all essentially speculative until we do the CT on May 7th, and I see my oncologist again on May 8th. I'll probably share them here in the near future, with the caveat that I'm projecting from insufficient (but not inconclusive) data rather than reacting to a formal clinical diagnosis and treatment plan.