FOLH1 and metastatic neoplasm: In all patients, 5/8 (62.5%) of the analyzed meth-ctDNA markers (AKR1B1 (p < 0.001), CHST11 (p < 0.001), KLF8 (p = 0.016), LDAH (p = 0.007), PCDHGC4 (p = 0.002)) and PSA levels (p < 0.001) differed significantly between patients with non-metastatic and metastatic disease on the PSMA scans, with the highest AUC under the ROC achieved by CHST11 (AUC—0.705, CI = [0.618; 0.793]) (Figs. 2B, S5, Tables S2, S7–9, S18).