e17118 Background: Prostate cancer is a major cause of cancer-related mortality among older men, highlighting the need for reliable and minimally invasive early detection strategies. Prostate-specific antigen (PSA)–based screening remains controversial due to limited mortality benefit, the risk of overdiagnosis, and subsequent overtreatment of indolent disease. In clinical practice, patients often retain limited information after consultations, and inconsistent risk communication by physicians can hinder informed shared decision-making. Serial assessment of circulating epithelial tumor cells (CETCs/CTCs) may represent a non-invasive approach to improve risk stratification in men at increased risk of prostate cancer. Methods: CETCs/CTCs were quantified in peripheral blood samples from men aged 50–85 years enrolled in a screening cohort (n = 35) and from patients undergoing PSMA-PET imaging for suspected prostate cancer (n = 49). PSA levels were measured at the time of PSMA-PET, and serial CETC/CTC trajectories were analyzed in relation to PSMA-PET findings. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis and survival outcomes. Results: PSA levels did not significantly differ between patients with PSMA-PET–positive and PSMA-PET–negative findings (p = 0.94). In contrast, CETC/CTC counts were significantly higher in PSMA-PET–positive patients compared with individuals in the screening cohort (p < 0.001). ROC analysis identified an optimal cut-off value of 450 CETCs/CTCs per mL of blood, yielding a sensitivity of 0.6 and a specificity of 0.7. Longitudinal analysis demonstrated distinct CETC/CTC trajectories: increasing counts were observed in 11 of 13 patients (90%) who subsequently developed PSMA-PET–positive findings, whereas only 2 of 21 patients (8%) with decreasing CETC/CTC counts were PSMA-PET positive. Kaplan–Meier analysis revealed a significantly reduced PSMA-PET–free survival in patients with rising CETC/CTC levels (p < 0.001; hazard ratio 9.48). Conclusions: Serial monitoring of CETCs/CTCs provides dynamic and minimally invasive information on prostate cancer activity. Increasing CETC/CTC trajectories were strongly associated with PSMA-PET positivity, supporting their potential role as early biomarkers for prostate cancer detection, progression assessment, and treatment monitoring.
Schott et al. (Thu,) studied this question.