@lvtexas , Did they get enough malignant tissue from the biopsy to "build" a Signatera test?

This is a test that extracts DNA tissue from your original tumor, builds a special "filter" to exactly match its DNA, and then checks later blood samples for evidence of ctDNA (Circulating Tumor DNA) with exactly that pattern. It provides a numerical result in tumor molecules per milliliter, and the trend over time can indicate the response you're having to the chemo.

Ideally it detects the presence of cancer before standard imaging does, but it's not a perfect test (twice returned zero-point-zero while my recurrent tumor was growing) and didn't return a positive (0.14) until after imaging did and my CA19-9 was near 300 (after that post-Whipple low of 12). Since my chemo resumed, the CA19-9 levels have dropped, and the Signatera numbers have all gone back down to 0.00 (which they note doesn't mean no cancer, just below their ability to detect). My PA said if it's > 0.00, you do have cancer, but if it's negative (0.00) it doesn't mean you don't.

We had lots of tissue from my Whipple procedure, and we re-run this Signatera test every 2-3 months to get data that supplements my biweekly CA19-9 tests. I hope they can do this or something like it for you.

I occasionally get static from my insurance company about the Signatera test "not being medically necessary," but always find a way to get it covered. Since you don't produce CA19-9, I think it would be easy to justify as medically necessary along with scans.