OBJECTIVES: Cancer treatment relies heavily on accurate diagnosis and effective monitoring of the disease. These processes often involve invasive procedures, such as colonoscopy, to detect malignant tissues, followed by molecular analyses to determine relevant biomarkers. This study aimed to evaluate the clinical performance of droplet digital PCR (ddPCR) for detecting Kirsten Rat Sarcoma Viral Proto-Oncogene (KRAS), Neuroblastoma RAS Viral Oncogene Homolog (NRAS), and B-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) mutations in circulating tumor DNA (ctDNA) from colorectal cancer patients using liquid biopsy. METHODS: ctDNA was isolated from colorectal cancer (CRC) patients (n = 110) and analyzed for KRAS, BRAF, and NRAS mutations. The ctDNA obtained through liquid biopsy was analyzed using ddPCR, and the findings were compared with sequencing data from tumor DNA archived in formalin-fixed paraffin-embedded (FFPE) blocks. RESULTS: For KRAS mutations, ddPCR achieved a sensitivity of 72.0% and a specificity of 71.4%. However, when pooling all target mutations (KRAS, NRAS and BRAF), the overall sensitivity and specificity were lower, at 48.3% and 51.1%, respectively. CONCLUSION: The results of this study indicate that the ddPCR analysis of ctDNA may provide complementary information for the molecular diagnosis of CRC patients.

Department of Biochemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic

Department of Comprehensive Cancer Care and Faculty of Medicine Masaryk Memorial Cancer Institute and Masaryk University Zluty kopec 7 Brno 656 53 Czech Republic

Department of Health Information Masaryk Memorial Cancer Institute Zluty kopec 7 Brno 656 53 Czech Republic

Department of Pathology Masaryk Memorial Cancer Institute Zluty kopec 7 Brno 656 53 Czech Republic

Department of Radiation Oncology Masaryk Memorial Cancer Institute Zluty kopec 7 Brno 656 53 Czech Republic

National Centre for Biomolecular Research Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic

Research Centre for Applied Molecular Oncology Masaryk Memorial Cancer Institute Zluty kopec 7 Brno 656 53 Czech Republic

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