@pattyclaire , The two genetic tests I'm aware of are 1) Invitae, which detects "germline" mutations you inherited from a parent; and 2) Guardant 360, which detects "somatic" mutations in DNA shed by cancer cells. The Guardant test may detect mutations for which it can't determine the cause (inherited or shed by a tumor), but a positive mutation reported in either helps identify your risk and plan your treatment. I think they both take 2-3 weeks to get initial results, so they can/should be performed while you're waiting for other stuff to get done, if possible.

We'll never know for sure what caused my recurrence. During the Whipple, my surgeon/pathologist saw cancer at the margins, then went back to cut out another half inch of pancreas, which was declared clean. After 3 months of clean scans and blood tests, MRI in the 4th month picked up a new 2 cm "lesion" where the remnant pancreas was stitched in to the old plumbing. Pretty fast growth in 3 months. Two prominent surgeons have told me the intraoperative pathology is not perfect; sometimes malignant cells remain present but out of sight.

I had an EUS biopsy of that lesion 3 days after the MRI, and it was all negative. They reported it as pancreatitis and recommended another blood/DNA test and MRI in 6 weeks. The doctor who took the biopsy was positive he got tissue from the appropriate (4) locations, but another doctor told me the post-Whipple anatomy and the fact the lesion was growing on the outside surface of that plumbing junction made it really difficult to reach.

Anyway, 6 weeks later the DNA and CA19-9 and MRI made it pretty clear the lesion was cancer, and imaging also spotted another metastatic tumor elsewhere in my abdomen. We don't know if that second tumor emerged from something that had escaped before the Whipple or after, but it cancelled any realistic chance I had for a surgical option.

I am not a fan of waiting and watching!