Prognostic serum markers in malignant pleural mesothelioma: Epidermal growth factor and platelet-derived growth factor

18097 Background: While no previous data has so far shown any difference between the efficacy of serum platelet-derived growth factor (PDGF-AB) and serum epidermal growth factor (EGF) in distinguishing MPM from benign pleural diseases, some pilot studies have shown the potentiality of both these markers in the prognosis of MPM patients. This study investigates this capacity by analyzing survival in a series of MPM patients. Methods: Using an ELISA method, EGF (ng/ml) baseline serum was determined in 83 newly diagnosed MPM patients, and in 62 cases PDGF-AB serum levels were also measured. After a median follow-up time of 11.8 months (range 0.4–52.1 months), the log-rank test was used to compare the survival curves, and Cox’s regression analysis was also performed. Results: Median serum values were 0.56 ng/ml (range 0.09–2.05) for EGF and 43.0 ng/ml (range 0.1–145) for PDGF-AB. Patients with EGF levels higher than the median level of 0.56 ng/ml had an average survival time of 9.4 months (95%CI: 5.7–13.2), while the average survival time of patients with below-median EGF levels was 13.2 months (95%CI: 10.6–15.8); a statistically significant difference (p=0.005). For patients with PDGF-AB levels higher than an assumed cut-off of 49.8 ng/ml, (above 75th percentile of MPM marker concentration) average survival was 7.9 months (95%CI: 4.5–11.3) as against the 14.9 months (95%CI: 10.3–18.7) in patients with below cut-off marker levels, again statistically significant (p=0.02). Cox’s regression analysis was performed on 42 patients in whom data on age, sex, histology, stage and platelet count were available. EGF and PDGF-AB levels higher than the selected cut-offs were confirmed as independent predictors of poor survival (HR=1.49; 95% CI: 1.04–2.13; p=0.03 and HR=1.96; 95% CI: 1.23–3.13; p=0.005, respectively). Conclusions: Our data suggest that circulating PDGF-AB and EGF levels are promising markers for clinical monitoring of MPM patients. No significant financial relationships to disclose.