Prevalence of colorectal cancer biomarkers and their impact on clinical outcomes in Riyadh, Saudi Arabia

OBJECTIVES: KRAS, NRAS, and BRAF mutations are commonly present in colorectal cancer (CRC). We estimated the frequency of KRAS, NRAS, and BRAF mutations and assessed their impact on survival and other clinical variables among Saudi patients. DESIGN: Retrospective cohort study design. SETTINGS: Oncology department of a tertiary hospital in Riyadh, Saudi Arabia. We gathered information from 2016 to 2018. PARTICIPANTS: Cohort of 248 CRC patients to assess the demographic data, pathological tumour features, response to treatment modalities, disease progression, and metastasis. STATISTICAL ANALYSIS USED: Correlation analysis using the chi-square test. Survival analysis using a Kaplan Meier method. Cox regression analysis to calculate the hazard ratios. RESULTS: Demographic data revealed that 84% of patients were diagnosed with CRC above the age of 50 years. Only 27% of patients presented with distant metastasis. KRAS mutations were the most prevalent (49.6%), followed by NRAS mutations (2%) and BRAF mutations (0.4%). Wild type tumours were found among 44.4% of patients. KRAS mutation showed no significant correlation with the site, type, pathological grade, and stage of the tumour. The mean survival time was shorter among patients with KRAS mutations than among patients with wild type KRAS tumours (54.46 vs. 58.02 months). Adjusted analysis showed that the survival time was significantly affected by patients’ age at diagnosis (P = 0.04). Male patients had an increased risk of mortality by 77% (hazard ratio: 1.77). CONCLUSIONS: Saudi CRC patients had a high frequency of KRAS mutations and a low frequency of BRAF mutations. The KRAS mutation status did not affect the patients’ survival.