Decoding molecular, clinico-pathological, and outcome differences between early-onset (EO, <50 years) and late-onset (LO, ≥50 years) mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer (CRC): Insights from real-world data.
Abstract
19 Background: The incidence of EO CRC is rising globally. While clinico-molecular features of EO mismatch repair proficient/microsatellite stable CRC have been described, less is known about EO dMMR/MSI-H tumors, which are highly immunogenic and may represent a biologically distinct subset. This study provides a comprehensive comparison of EO versus LO dMMR/MSI-H CRC. Methods: We retrospectively analyzed CRC samples profiled by next-generation sequencing (NGS) of DNA/RNA and immunohistochemistry (IHC) at a CLIA-certified lab (Caris Life Sciences; Phoenix, AZ). Patients (pts) with confirmed dMMR/MSI-H CRC were stratified into EO and LO cohorts. Consensus Molecular Subtypes (CMS) were determined from RNA expression profiles using a 600-gene classifier. Statistical comparisons used chi-square, Fisher’s exact or Mann-Whitney U tests with multiple-testing correction (q
Fields of Study & Subjects
Genetic factors in colorectal cancer
Ferroptosis and cancer prognosis
Multiple and Secondary Primary Cancers
Publication details
- Journal / source
- Journal of Clinical Oncology
- Publisher
- American Society of Clinical Oncology (ASCO)
- Volume
- 44
- Issue
- 2_suppl
- Pages
- 19–19
- Publication date
- 10 January 2026
- Language
- EN