Prognosis and immunotherapy efficacy in dMMR&MSS colorectal cancer patients and an MSI status predicting model

This study examined colorectal cancers with deficient mismatch repair by immunohistochemistry but microsatellite-stable status by PCR and compared their outcomes with canonical dMMR/MSI-H tumors. The authors showed that this discordant subgroup had worse survival and derived less benefit from immunotherapy, then developed a practical MSI prediction model to improve identification of these patients in clinical workflows.