Circulating tumor DNA as a predictive biomarker for treatment response and survival in metastatic colorectal cancer.

PURPOSE: To explore the potential of circulating tumor DNA (ctDNA) as a prognostic biomarker to predict treatment response and survival outcomes in patients with metastatic colorectal cancer (mCRC). METHODS: A retrospective analysis was conducted on 134 patients with mCRC who were treated between January 2020 and December 2021. The patients were classified into ctDNA-negative and ctDNA-positive groups based on plasma ctDNA detection. Demographic, clinical, and laboratory parameters, treatment response, survival outcomes, and adverse events were recorded and analyzed. RESULTS: No significant differences were observed in baseline characteristics between the two groups. Compared to the ctDNA-positive patients, ctDNA-negative patients exhibited superior outcomes, including a higher objective response rate (65.22% vs. 46.15%), disease control rate (81.16% vs. 63.08%), progression-free survival (8.24 ± 1.02 vs. 7.86 ± 0.91 months), overall survival (24.58 ± 3.58 vs. 23.27 ± 3.46 months), and 1-year survival rate (73.91% vs. 55.38%). The ctDNA-positive group had a significantly higher incidence of adverse events. Correlation analyses revealed significant associations between ctDNA status, tumor markers, treatment response, and survival outcomes. CONCLUSIONS: ctDNA is a promising noninvasive biomarker for predicting treatment response, survival, and adverse events in mCRC, potentially guiding personalized therapeutic strategies.