Has anyone's CA 125 fluctuated while on Avastin and Cytoxan?

I know CA 125 is not a reliable tumor marker test to begin with. I had it measured today after 3 full treatments of Avastin and Cytoxan. While it didn't go up much, it did rise a little, but is still well below the normal limit of 35. Has anyone else been on Avastin and Cytoxan (the oral pill) and had the CA 125 actually rise instead of going down? This is so frustrating, I really don't know what the purpose of this tumor marker is to begin with. I know there is another tumor marker test that can be run in conjunction with this, the HE 4. But so far it isn't done where I presently go.