I had an IPMN in the tail of the pancreas found in summer of 2021. It was 2 cm. The EUS determined it was benign. So it surveilled again in June 2022. It was 2.1 cm and the main duct was dilated. I had a distal pancreatectomy at the time, and there was cancer found in the resected tissue. But no spread. I was stage 1b. I had 12 rounds of Folferinox and CT scan showed a spot on my liver not previously noticed. Looks like cancer again. Biopsy in a couple of days. CA 9-19 spiked to 650. Doctor had hoped that Folferinox would cure, but now the hope is to control. Like you say, everyone is different and I don't know if any of my experience is helpful, but this form of cancer seems particularly sneaky and hard to stop, even in a case like mine where it started out optimistic. Wish you the best.