I am going thru a similar situation. Colon cancer, Chemo, radiation and then surgery. Afterwards, my Signatera tests were 0 for about 5 months. Then they went to .03, .06, 1.3, 3.3- we did scans and didn't find anything until the 3.3 reading and at this point we found a 1/4 inch spot on my lung. We did a cryoablation to freeze out the spot and kill it. This procedure was less invasive and caused less residual damage than a surgery or radiation. It really wasn't too bad at all and I've had 5 of these total to kill spots on my lung and liver. My next signatera test was a 6 and we found a small spot on my lung and one on my liver that was cryoablated. This spot was biopsied and tested positive. The other spots have been too small to get a biopsy when they were cryoablated. On the next scan, we found another spot on my liver that has been cryoablated as well. And, at this point my signatera test shot to a 17 which was quite alarming. After consultation, everyone agreed that my cancer was not localized and had become more systemic. So, back on a full chemo treatment and starting an immunotherapy drug as well soon. After 2 chemo treatments my readings shot down to 3.3- finally on the right track. I fully expect to get these back to zero. We will do scans and Signatera test around Nov. 5 to see if anymore spots have developed and take care of if needed. I have never felt any affects of the tumor or spots. We simply get rid of anything that appears as quickly as possible. I will do a total of 6 heavy duty Chemo infusions at 2 week intervals followed with 11 more medium infusions. They drop the worst drug after 6. All I can advise is to stay diligent and positive. It seems like smaller spots are easier to manage than larger ones. Scans with Signatera tests help find these spots as early as possible, hopefully, before they have time to spread any further. I hope this info may be useful. There isn't much out there about Signatera testing. Also, use the portal to ask questions night or day. Keep fighting and stay strong!!!