I too had Stage 3B(2/2024) with resection and 12 rounds of FOLFOX and 25 rounds of radiation in my abdomen area. My cancer started outside on my Cecum and surrounded my appendix. Some of the tumor was caught on my abdominal wall. It was all removed by non Oncological surgeon who placed a staple in the area it was touching so they could radiate it. I started the Signatera testing as soon as I started chemo at the insistence of my Daughter. My Oncologist did not fully embrace this test at the time. 3x it came back negative. The 4th time was positive( 1.47) about 3 mos after chemo ended. The night I got the positive Signatera test result, earlier that day, I had gotten clean scan results, clean blood work and was given the green light and see you in 6 months by my Oncologist. I was shocked and so upset. A PET Scan was immediately done. The PET came back with 2 glaring lymph nodes in close proximity to where this started but behind close to my spine. I elected surgery which my Oncologist seemed to encourage. Surgery was done by an Oncology Surgeon who was able to look around. He took additional lymph nodes and a suspicious Peritoneal nodule. The 2 suspicious lymph nodes and the nodule came back positive, 3 other nodes and 2 other nodules were negative. Surgery was pretty extensive but I know my body and know I am in good shape and can recover. I am back to swimming daily and working out. Took about 6-7 weeks to start feeling good again. Chemo is a wild card for me and scares me. I want my immune system to be able to work and combat this. That is what it is supposed to do.I recently had my Signatera done and it was negative which was about 7 weeks after surgery. Why they do not do PET Scans after surgery and before radiation is mind blowing to me. I don't know if chemo was necessary in my case but it is their protocol. I will continue to do my own research but much more so now and rely on God more for all of this. The anxiety of the Signatera results is what I am trying to manage now because it will be an ongoing test. Had I not gotten the Signatera, I would not have found out about the Cancer still in me until my next visit which was in 6 months.