The role of CD146 in serous ovarian carcinoma

The heterogeneous phenotype of epithelial ovarian cancer (EOC) explains the unpredictable behaviour in terms of response to therapy, time to progression and survival. In this context, CD146, a cell adhesion molecule, has been focused on as a marker of poor prognosis in various solid cancers, being also capable to modulate the activity of endothelial cells. Therefore, we proposed to investigate its role in serous ovarian carcinoma.

The study included 101 patients diagnosed with EOC and treated within "Ion Chiricuta" Oncology Institute by optimal surgical debulking followed by platinum-based chemotherapy. Clinico-pathological characteristics were collected from patient files. CD146 expression was assessed by immunohistochemistry in serous ovarian carcinoma primary tumours, taking into account both staining intensity and the percentage of positive tumor cells. Expression of CD146 in endothelial cells of tumour microvessels was also evaluated. CD34 immunostaining was used for intratumoral microvessel density estimation.

CD146 positivity in tumor cells was objectified in 49.5% of samples and 37.1% presented a high CD146 endothelial expression. Our analysis showed that CD146 was as reliable as CD34 for microvascular density estimation. The distribution of cases according to CD146 tumor expression was similar regardless of age, initial serum CA125 level, FIGO stage, presence/absence of malignant ascites. Multivariate analysis confirmed that expression of CD146 in tumor cells was a negative prognostic factor for overall survival, significantly asociated with a higher risk of chemotherapy resistance.

Although CD146 immunoreactivity in tumor cells did not correlate with the routinely used clinico-pathological parameters, expression of CD146 in tumor cells was an independent pronostic factor for survival in serous ovarian carcinomas. Moreover, CD146 might be regarded as a novel biomarker of tumor neovasculature.