This is my understanding of it.if we’re talking about the same thing. Liquid biopsy is not as accurate as sending actual biopsy tissue.
I get signatera tests quarterly. The process starts with sending a biopsy (tissue or blood draw) then after surgery, you send a blood draw and they try to see if there’s any cancer cells that are in the blood from that particular tumor. That’s what they call MRD, molecular residual disease.
If you send them tissue at the beginning, the results are more “specific”, meaning positive means recurrence at some point.
If you send a liquid biopsy, it’s less accurate.
These tests are not 100% on the negative side. Meaning negative does not mean no possible recurrence. From what I read, it’s more like 50%. They are more “correct” on the positive side, if they find it, it’s 80% recurrence within a years or something like that.
52M DX: RC lower rectum, guessing now 2cm from AV 4/27/2021
T3N0M0 adenocarcinoma with signet ring cell features
Tumor size 30mm
Tumor grade: G3
Baseline CEA 1.0
MSI status: MSS pMMR
Started Folfox 5/12/2021
Switched to FOLFIRINOX from session 2. 8 rounds total.
CT+MRI tumor contained shrunk 80%, no spread to other organs.
CRT started xeloda + 28 days Radiation 9/27-11/04
NED as of 4/06 CT/MRI/sigmoidoscopy
On W&W 04/06/2022