Abstract:

Objective To investigate the heterogeneity between left? and right?sided colorectal cancer （CRC） in terms of clinical pathological features and gene expression， thereby providing a foundation for personalized treatment. Methods A retrospective analysis was conducted on the clinical data， next?generation sequencing （NGS） results， and treatment plans of 186 CRC patients treated at the forth hospital affiliated of guangxi medical university from July 2020 to August 2023. Patients were categorized into left?sided CRC （n = 134） and right?sided CRC （n = 52） based on tumor location. Clinical and pathological characteristics were analyzed using SPSS 24.0 software， and Kaplan?Meier survival curves were generated to compare overall survival （OS） between groups using the Log?rank test. Additionally， this study compared the clinical and pathological features， NGS?based gene mutation profiles， and prognostic differences between left? and right?sided CRC patients. Results In the clinical and pathological characteristics， no significant differences were observed between left? and right?sided CRC patients regarding gender， distant metastasis， ECOG performance status， TNM stage， or levels of carcinoembryonic antigen （CEA） and carbohydrate antigen 19?9 （CA19?9） （P > 0.05）. However， there were significant differences in age （P < 0.05）. In terms of gene mutation characteristics， the mutation frequencies of NRAS， BRAF， and APC genes did not differ significantly between left? and right?sided CRC patients （P > 0.05）. However， right?sided CRC patients exhibited significantly higher mutation frequencies of PIK3CA and SMAD4 genes， as well as a higher prevalence of microsatellite instability （MSI）， compared to left?sided CRC patients （P < 0.05）. Conversely， left?sided CRC patients had significantly higher TP53 mutation frequencies than right?sided CRC patients （P < 0.05）. In prognostic analysis， after a three?year follow?up， no significant difference in OS was observed between the two groups. Conclusions Significant disparities are observed in the clinical pathological features and gene expression profiles between left? and right?sided CRC. These findings indicate that distinct approaches should be adopted in clinical diagnosis and treatment to facilitate personalized and precise care.

Key words: left- and right-sided colorectal cancer, clinical pathological characteristics, gene testing, heterogeneity analysis