Disseminated Tumor Cells (DTCs) in Patients with Cervical Cancer Reveal Mesenchymal Properties and Potential Therapeutic Targets—A New Perspective?

Despite effective primary treatment, approximately 20% of cervical cancer patients experience recurrence, which may be driven by early hematogenous dissemination. While circulating (CTCs) and disseminated tumor cells (DTCs) are established prognostic markers in breast cancer, their role in cervical cancer remains poorly defined. Current detection methods rely predominantly on cytokeratin (CK) expression, but epithelial–mesenchymal transition (EMT) may lead to CK downregulation, potentially compromising detection sensitivity. We analyzed bone marrow (n = 43) and blood samples (collected pre-surgically and at follow-up) from cervical cancer patients. DTCs and CTCs were detected using a standardized CK based immunocytochemical assay. A multi-parameter immunofluorescence (IF) approach was employed to simultaneously assess CK, vimentin (Vim), p16, PD-L1 and VEGF on DTCs. Marker expression profiles were compared with matched tumor tissue and correlated with clinical and pathological parameters. CTCs were detected in 16% (7/43) of pre-surgical blood samples. DTC positivity increased from 56% (24/43) using CK based detection to 74% (32/43) when assessed via multi-parameter IF. A total of 248 DTCs were identified (median: 7 per patient). The most prevalent DTC phenotype was Vim+ (54%), followed by CK+ (12%), Vim+/VEGF+/p16+ (7%), and CK+/Vim+ (4%). Significant correlations were observed between p16 and VEGF (r = 0.631, p < 0.001) and between PD-L1 (r = 0.323, p < 0.001). Discordance between DTCs and tumor tissue reached 43–64%, primarily attributable to PD-L1 gain in DTCs. Over 70% of DTCs lacked CK, with majority exhibiting vimentin positivity, indicative of a mesenchymal phenotype. Vim+ and VEGF+ DTCs were associated with disease recurrence, suggesting their prognostic value. These findings underscore the limitations of relying solely on CK for DTC detection and highlight the potential of EMT and immune-related markers as novel biomarkers in cervical cancer. Further validation in larger, prospective cohorts is warranted.