High expression of mesothelin in advanced serous ovarian cancer is associated with poor prognosis

Mesothelin is a cell surface glycoprotein which is highly expressed in various types of epithelial cancers. Its expression level is associated with poor prognosis in many cancer types. The aim this study was to evaluate the association of the level of mesothelin expression with clinicopathological characteristics and its prognostic significance in patients with advanced serous ovarian cancer (SOC).

Tissue blocks from a total 42 patients with advanced SOC treated at the medical oncology clinic of Izmir Katip Celebi University Ataturk Training and Research Hospital between 2006 and 2013 were evaluated. Immunohistochemical staining for mesothelin was performed. Clinical characteristics, optimal or suboptimal operation, response to platinum-based chemotherapy, and overall survival (OS) were analyzed.

The cut-off value of 45 for mesothelin H-score determined by ROC analysis predicted survival with 86% sensitivity and 75% specificity (p=0.020). We found a notable negative correlation between mesothelin H-score and OS (r = -0.570, p=0.0001). The median OS was 67 months (95%CI, 36.114 to 97.886) in the low-staining mesothelin H-score group and 27 months (95%CI, 22.238 to 31.762) in the high-staining mesothelin H-score group (p=0.002). Univariate analysis showed that the clinical stage IV disease (p=0.023), platinum chemoresistance (p=0.001), higher mesothelin H-score (p=0.002), and suboptimal surgery (p=0.024) were associated with worse OS. In the multivariate Cox regression model, mesothelin H-score (B=1.15, 95%CI=1.016 to 9.850, p=0.047) and the status of platinum sensitivity (B=-.916, 95%CI=.185 to -.864, p=0.020 were statistically significant predictors for OS.

These results indicated that high mesothelin H-scores were significantly associated with poor prognosis in patients with advanced SOC.