BAT26 Only Microsatellite Instability with High Tumor Mutation Burden-A Rare Entity Associated with PTEN Protein Loss and High PD-L1 Expression.

ABSTRACT: Detecting microsatellite instability (MSI) in advanced cancers is crucial for clinical decision-making, as it helps in identifying patients with differential treatment responses and prognoses. BAT26 is a highly sensitive MSI marker that defines the mismatch repair (MMR) status with high sensitivity and specificity. However, isolated BAT26-only instability is rare and has not been previously reported. Of the 6476 cases tested using pentaplex MSI polymerase chain reaction, we identified two BAT26-only instability cases (0.03%) in this study. The case #1 patient was diagnosed with endometrial adenocarcinoma without MMR germline mutations. The endometrial tumor showed BAT26-only instability, partial loss of MLH1/PMS2 protein expression, and a high programmed cell de

SUBMITTER: Kang SY 

PROVIDER: S-EPMC9504117 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature