Updated: Mar 23, 2019
This morning, a nurse from AZ Oncology called to tell us good news about a blood test David had done yesterday called carcinoembryonic antigen (CEA) tumor marker. (A tumor marker is a substance produced by a tumor or a person's body in response to cancer.) Yesterday's result was 4.3. It was 467 when he was diagnosed last November, and it was 16.8 just last month.
According to medicinenet.com, the normal range is <2.5 ng/ml in an adult non-smoker, benign disease does not usually cause a CEA value over 10 ng/ml, and levels over 20 ng/ml before therapy are associated with cancer which has already metastasized (which is the case with David). Furthermore, the site says "If the CEA is high before treatment, it should fall to normal after successful therapy. A rising CEA level indicates progression or recurrence of the cancer."
So the chemo appears to be working, and we're keeping our finger crossed that David's next result will be even closer to the normal range. Just to be clear, though, we're not sure what it will mean if it is in or near the normal range. We need to ask Dr. Brooks about that.
We suspect it means the treatment has successfully stopped the spread of the cancer and shrunk the existing tumors, but beyond that, we do not know. It might mean David is headed towards or in "remission," but once again, we're not sure what that means.
Based on what three oncologists told us when David was first diagnosed, his cancer is not curable, because it has spread so much, but chemo could beat it back enough that David could have one-to-two years before the cancer would start growing again. Of course, you never know, especially with new cancer treatments becoming available. Perhaps a cure will become available. Plus, we still have the other immunotherapy drug (pembrolizumab), which David's genetic test indicates might work, waiting in the wings as well. Dr Brooks plans to use that when the cancer starts growing again.
All in all, the falling CEA number is encouraging. When Dr. Brooks does another CAT scan after chemo cycle 6, that will give us more-definitive insight into the state of the cancer.