Evaluation of ct-DNA and Mutational Status in Liquid Biopsy of Patients with Metastatic Colorectal Cancer

Introduction Liquid biopsy has become an increasingly important tool in clinical oncology due to the utility of circulating tumor DNA (ct-DNA). Plasma ct-DNA levels reflect a patient’s tumor burden and provide valuable information for personalized treatment strategies. Colorectal cancer (CRC) is among the most frequently diagnosed malignancies worldwide and remains a leading cause of cancer-related mortality. The implementation of personalized therapy can significantly improve clinical outcomes in these patients. Aim This study aimed to evaluate ct-DNA in patients with metastatic CRC undergoing therapy in our department, using next-generation sequencing (NGS) to identify tumor mutations in both tissue and cell-free plasma DNA. Methods A total of 45 patients newly diagnosed with metastatic CRC were enrolled in the study. ct-DNA evaluation was performed at diagnosis, and both tissue and plasma samples were analyzed using NGS to assess the mutational profile. Results The most frequent mutation identified was in KRAS. A high level of concordance was observed between tissue and plasma samples regarding ct-DNA detection and mutational status. Sequential ct-DNA analysis during therapy revealed dynamic changes in mutation profiles over the course of treatment. Conclusion Liquid biopsy offers significant clinical value as a minimally invasive tool for personalized therapy in metastatic CRC. NGS-based liquid biopsy enables real-time evaluation of ct-DNA and mutation status during treatment, supporting therapeutic decision-making and disease monitoring.