Early Plasma Circulating Tumor DNA as a Potential Biomarker of Disease Recurrence in Non-metastatic Prostate Cancer

Purpose In non-metastatic prostate cancer (nmPCa) setting, it is important to early identify the patients at risk of biochemical recurrence (BCR) for immediate postoperative intervention. Our study aimed to evaluate the potential clinical utility of circulating tumor DNA (ctDNA) for predicting disease recurrence.Materials and Methods This real-world observational study evaluated 161 cases of nmPCa undergoing next-generation sequencing at our institution. A total of 139 ctDNA samples and 31 biopsied tumor tissue underwent genomic profiling. The study endpoint was BCR after radical prostatectomy. Relationships between the ctDNA status and the biochemical progression-free survival (bPFS) were analyzed by log-rank test and multivariate Cox regression.Results Of 161 enrolled patients, 19 (11.8%) harbored deleterious alterations in <i>NCOR2</i>, followed by <i>BRCA2</i> (3.7%), <i>ATR</i> (2.5%), and <i>CDK12</i> (2.5%). Of available pre-operative blood samples (n=139), ctDNA was detectable in 91 (65.5%). Until last follow-up, 56 of 68 patients (85.3%) with detectable ctDNA had achieved BCR, whereas only eight of 39 patients (20.5%) with undetectable ctDNA had achieved BCR. Patients who had undetectable ctDNA experienced significantly longer bPFS compared with those who had detectable ctDNA (not available vs. 8.2 months; hazard ratio, 0.14; p < 0.01). Pre-operative ctDNA status was a significant prognostic factor of disease recurrence.Conclusion Pre-operative ctDNA detection could identify patients at high risk of recurrence and has the potential to inform immediate postoperative interventions, but these approaches remain to be validated in prospective studies. ctDNA studies can provide insights into accurate monitoring and precise treatment rather than simply following routine clinical care.