Hi, I recently asked my oncologist about having this blood test, as I also understood that it can be an indicator of cancer activity if it becomes raised. My oncologist was most against this test, as he said it was very inconclusive, and caused more problems than it solved. He said the levels can go up when there is nothing wrong, and can remain within the normal limits when something is there. It may well be useful for other cancers, but when used for breast cancer he thinks it isn't worth the effort. He told me that recent research in USA has proved this to be the case. I was happy with this explanation. Love Chris xx