Plasma osteopontin and the prognosis of pleural mesothelioma.

Abstract

11109 Background: Cytoreductive surgery for malignant pleural mesothelioma (MPM) should be reserved for patients with favorable tumor biology. Osteopontin (OPN) and the ratio of absolute neutrophil to absolute lymphocyte counts (NLR) have been reported as possible prognostic biomarkers. These were studied with other clinical/ laboratory variables in a mixed surgical/non-surgical MPM population to define independent predictors of survival (OS) and progression (TTP). Methods: Forty-four MPM patients (12 F, 32M; 26 cytoreduction, 18 no cytoreduction; 31 epithelial, 13 non-epithelial; 15 Stage I/II, 29 Stage III/IV) were examined with regard to pretreatment plasma OPN (ELISA, R&D, Minneapolis, MN), NLR age, gender, therapy, histology, stage, platelet count and WBC count. Cut points for age, OPN, NLR, platelets, and WBC were determined by X-tile Software (Yale, New Haven, CT) and univariate/multivariate Cox analyses performed. Results: Median OS were 11 m, 21m, and 8m for all 44 MPMs, cytoreduced and non-cytoreduced MPMs, respectively. Of platelet count, WBC, NLR, and OPN, only OPN was statistically significant between Stage I/II and Stage III/IV (80.3 ng/ml vs 148 ng/ml, p<0.018). The only independent covariate predictive of OS was plasma OPN. For TTP in cytoreduced patients, only age, stage, platelet count, and OPN were significant in univariate analysis, and multivariate modeling retained stage (p=0.04, HR=2.75, 95% CI=1.0517 to 7.1879) and OPN (p=0.0008, HR=17.471, 95% CI=3.3054 to 92.3461). Conclusions: Plasma OPN is promising for the stratification of tumors into good or bad risk categories and to help select potential candidates for cytoreduction and further postoperative therapy. [Table: see text]