Yes, agreed. With sine mutations CA19-9 is a very good indicator of cancer spread. I have ATM mutation and my drs agreed it’s a very good indicator for me. It can fluctuate with inflammation or decrease of chemo levels in your system. I’m proud to say I’m obsessed with my ca19-9 and it’s why my oncologists continually remark “well we’ve caught it (the spread) very early”. It’s a balancing act not to be full of anxiety when those numbers go up, but it also can be one of the quickest and cheapest tools you can use in your arsenal to fight this disease. My suggestion is to fill your time with stuff you enjoy in order to mitigate that anxiety when those numbers go up, and please press your drs to get the imaging that might verify the rise in CA19-9.