Circulating endothelial cell (CEC), a surrogate of tumor angiogenesis, as a diagnostic and prognostic marker in malignant pleural mesothelioma (MPM).

Abstract

10577 Background: Circulating endothelial cell (CEC) is a potential surrogate of tumor angiogenesis, but the clinical value in malignant pleural mesothelioma (MPM) remains unknown. Methods: Patients who presented with suspicion or diagnosis of MPM were prospectively evaluated. CECs in 4.0mL of the peripheral blood were captured and quantitatively evaluated with the CellSearch system. Tumor angiogenesis was evaluated by immunohistochemical staining with an anti-CD34 antibody and represented as microvessel density (MVD). Results: Among 109 patients included in this study, 79 were finally diagnosed as having MPM and 30 as non-malignant diseases (NM). A significant positive correlation was observed between CEC-count and MVD (Spearman r=0.44, p<0.01). CEC-count was significantly higher in MPM than NM (131 and 40, p<0.01), which provided a significant diagnostic performance in discrimination between MPM and NM with the AUC-ROC of 0.689 (95%CI, 0.581-0.798; p<0.01). Stage IV MPM cases tend to show a higher mean CEC-count than stage I-III MPM cases (151 vs. 106; p=0.10). Higher-CEC (≥50) was a significant prognostic factor to predict a poor prognosis. Conclusions: CEC proved to be a surrogate of tumor angiogenesis in MPM. In addition, CEC was a promising clinical marker not only in discrimination between MPM and non-malignant diseases but also in predicting prognosis in MPM. This study was supported by “The Special Coordination Funds for Promoting Science and Technology from the Japanese Ministry of Education, Culture, Sports, Science, and Technology.” Nonmalignant MPM P value No. of pts 30 79 CEC-count (mean) 40 131 P<0.01 Overall survival (median, months) 11.4 m (CEC≥50) vs 20.0 m (CEC<50) P=0.03 Overall survival rate (%, at 1/2 yrs) 49%/15% (CEC≥50) vs 69%/33% (CEC<50)