Utility of Mesothelin, L1CAM and Afamin As Biomarkers in Primary Ovarian Cancer

Background: We evaluated the prognostic value of the new serum biomarkers mesothelin (cell surface glycoprotein and tumor differentiation antigen), L1 cell adhesion molecule (L1CAM) and afamin (vitamin D-binding protein) alone and in combination with cancer antigen 125 (CA125) in serum samples of 154 patients with first-diagnosis of primary ovarian cancer, before surgery and after platinum-based chemotherapy. We correlated these findings with clinical parameters and evaluated their prognostic value with regard to overall survival (OS).

Materials And Methods: Blood (9 ml) was obtained before surgery (n=154) and after chemotherapy (n=82) for the measurement of serum markers using commercial Enzyme Linked Immunosorbent Assay (ELISA) kits for mesothelin, L1CAM, afamin and CA125. Mesothelin positivity was defined as >2.0 nM, L1CAM as >10 ng/ml, afamin as <45 mg/l and CA125 as >35 U/ml, respectively.

Results: Before surgery, mesothelin positivity significantly correlated with advanced International Federation of Gynecology and Obstetrics (FIGO) stage (p=0.002), residual postoperative tumor (p<0.0001), serous histological subtype (p<0.0001) and higher age (p=0.013). Elevated CA125 levels significantly correlated with advanced FIGO stage (p<0.0001) and grading (p=0.012). After chemotherapy, mesothelin as well as CA125 levels, were significantly associated with FIGO stage (p=0.041 and p=0.017) and residual tumor (p=0.022 and p=0.002) while L1CAM correlated with platinum sensitivity (p=0.041). In contrast, afamin at all determined time points showed no correlation with any of these parameters. The combination of markers did not add any significant power to their use.

Conclusion: Mesothelin and L1CAM appear to correlate with clinical prognostic parameters and might be useful biomarkers for therapy monitoring and, thus, could serve as attractive targets for therapy of ovarian cancer.