How would you approach a patient with Stage III gastric cancer and poor performance status who had large residual disease (ypT4N1) after neoadjuvant capecitabine and was later found to be MSI-H?

We are flying in the "no data" zone here. The MATTERHORN study, led by Dr. Janjigian et al., is a global 948-patient study in which patients with resectable gastric/GEJ adenocarcinoma received perioperative FLOT +/- perioperative (neoadjuvant/adjuvant) durvalumab. The press release on 6/2/23 showed ...

I don't think there will be a data driven answer to this situation.

What we know is MSI-H patients don't do well with perioperative or adjuvant chemotherapy from Smyth et al., PMID 28241187 and Pietrantonio et al., PMID 31513484 (Although DANTE might suggest otherwise with pCR of 27% w FLOT alone).

Al...