Identification of clinicopathological-specific driver gene and genetic subtyping of colorectal cancer

This study analyzed targeted sequencing data from 6530 tissue samples from patients with metastatic Chinese colorectal cancer (CRC) to identify low mutation frequency and subgroup-specific driver genes, using three algorithms for overall CRC as well as across different clinicopathological subgroups. We analyzed 425 cancer-related genes, identifying 101 potential driver genes, including 36 novel to CRC. Notably, some genes demonstrated subgroup specificity; for instance, ERBB4 was found as a male-specific driver gene and mutations of ERBB4 only influenced the prognosis of male patients with CRC. This sex disparity of ERBB4 was validated in an independent large-scale Memorial Sloan Kettering Cancer Center CRC cohort with 2444 samples. Furthermore, using network-based stratification based on protein-protein interaction, we classified the microsatellite stable (MSS) and unstable (MSI) CRCs into six and three major subtypes, respectively, each showing unique phenotypes and prognoses. In MSS CRC, cluster 5 (APCAMER1-KRAS) and cluster 2 (RNF43-BRAF-PIK3CA) were predominant, and cluster 5 showed a superior overall survival compared with cluster 2. This extensive heterogeneity in driver gene mutations underscores the complexity of CRC and suggests significant implications for treatment and prognostic assessments.