Is there strong evidence to use TMB found in circulating tumor DNA to guide the use of ICI in metastatic colon cancer?

The benefit of immunotherapy for patients with high TMB was demonstrated in the KEYNOTE 158 study (Marabelle et al., PMID 32919526). This is a phase 2 study that enrolled 1076 patients with advanced solid tumor (a total of 10 different tumor types including anal, biliary, cervical, endometrial, meso...

Circulating tumor DNA has a consistently higher TMB than tissue. As noted by Dr. @Dr. First Last, MSKCC has demonstrated (Rousseau et al., PMID 33761214) no benefit for patients that are not MSI-H or POLE/POLD mutated (specific domain of polymerase also to generate the hypermutation phenotype) metas...