Serum levels of the soluble transmembrane adhesion molecule P-cadherin in healthy women and in patients with malignant and benign ovarian tumors

Background: Cadherins are calcium-dependent transmembrane glycoproteins whose extracellular domains mediate homophilic intercellular interactions. Their soluble forms (s-cadherins), generated through proteolytic cleavage of transmembrane proteins or alternative mRNA splicing, are not anchored in the cell membrane and circulate in the extracellular space or peripheral blood. In the context of carcinogenesis, the role of P-cadherin remains a matter of debate: some studies associate P-cadherin with tumor growth suppression, while others indicate its tumor-promoting properties. Publications on the significance of the soluble P-cadherin in various disorders are scarce. Aim: To perform a comparative analysis of serum sP-cadherin levels in healthy women and in patients with malignant and benign ovarian tumors to assess the clinical significance of the marker. Methods: The retrospective study included 56 patients with epithelial malignant ovarian tumors (median age 57 years), 10 patients with benign ovarian tumors (median age 55 years), and 11 healthy women (median age 56 years) who underwent examination and treatment from 2023 to 2024 in three oncology clinics. Serum levels of sP-cadherin before the initiation of specific treatment were determined with the Human P-Cadherin ELISA Kit (RayBiotech, USA). Results: In the ovarian cancer group, the majority of the patients had the serous type of the tumor (n = 46, 82%), stage III to IV of the disease (n = 45, 80%), T3 and T4 tumors (n = 42, 75%), mostly without regional (N0: n = 41, 73%) and distant metastases (M0: n = 43, 77%). The results of the ROC analysis showed that serum levels of the soluble P-cadherin could not be used as a reliable diagnostic criterion for ovarian malignancies: the area under the curve (AUC) was 0.793 (confidence interval 0.671 to 0.915; p = 0.002). At the optimal cut-off value of 3.01 ng/mL, the test’s sensitivity and specificity were 77% and 73%, respectively. The serum sP-cadherin levels did not show a significant correlation with the key clinical and morphological characteristics of ovarian cancer. Conclusion: Patients with ovarian cancer have an increased serum sP-cadherin level. Further research on this glycoprotein to assess its role in disease outcomes and chemotherapy efficacy is expedient.