I had my first episode with bc 9 years ago. Since then, they checked my tumor markers every 6 months. About 4 years ago they went up to 57 and I had bone scan and redid tumor marker which was down to 22 in a month. Then, last year my marker went up to 67. I had a PET scan and found a tumor which was self-contained and had not spread, thankfully. I guess tumor markers aren't completely reliable but can give doctors some direction.
Jeremiah 29:11 - "For I know the plans I have for you," declares the Lord, "plans to prosper you and not to harm you, plans to give you hope and a future."
I for one am not that familiar with tumor markers or the meanings, my onc does not use them with me. I have heard that small fluctuations occur, and can be caused by a cold or even menstruation. I think it is patterns, steady increases or large jumps that they would be concerned.