More subtle microsatellite instability better predicts fluorouracil insensitivity in colorectal cancer patients.

ABSTRACT: Microsatellite instability (MSI) is now widely used as an indispensable biomarker. However, the relationship between MSI-H (high) and defective DNA mismatch repair (MMR) is not as straightforward as has been expected. Genome-edited cells carrying Lynch syndrome mutations do not exhibit drastic MSI typical in MSI-H (i.e. Type B) but more subtle MSI (i.e. Type A). In this study, we explored a connection between Type A MSI and 5-fluorouracil (5-FU) resistance in colorectal cancer patients. Using our precision and high-resolution MSI assay technique, tumour microsatellites were analysed in 30 colorectal cancer patients treated with FOLFOX or CAPOX. Among 30 tumours, eleven (37%) were judged as Type A MSI-positive. In Type A MSI⁺ tumours, the patient response to fluoropyrimidine and

SUBMITTER: Miyashita K 

PROVIDER: S-EPMC11549419 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature