Serum B-type natriuretic peptide is affected by neoplastic edema in brain tumor patients

OBJECTIVE: A positive correlation between serum B-type natriuretic peptide levels and the amount of dislodgement of intracranial structures (mass effect) produced by brain tumors has been demonstrated previously. The aim of our prospective observational study was to evaluate a possible relationship between serum B-type natriuretic peptide levels and the amount of neoplastic edema in patients affected by brain tumor. METHODS: We prospectively studied 110 patients with a supratentorial brain tumor. Serum N-terminal-pro B-type natriuretic peptide was measured and brain magnetic resonance images were analyzed to discriminate between neoplastic tissue and perilesional edema. A multivariate linear regression model predictive for serum N-terminal-pro B-type natriuretic peptide levels was generated. RESULTS: The radiologic diagnoses were meningioma in 45 patients (40.9%), glioma in 33 (30%), and metastasis in 32 (29.1%). A mass effect was present in 29 (26.4%) patients. Serum N-terminal-pro B-type natriuretic peptide was 125.61 +/- 174.14 pg/mL (median 60 pg/mL, interquartile range 28-139 pg/mL). Four variables were entered into a multivariate linear regression model predictive for serum N-terminal-pro B-type natriuretic peptide values: age, neoplastic edema volume, metastatic lesion, and the presence of a mass effect (whole model P < 0.0001; R-2 = 0.5555; adjusted R-2 = 0.5294). CONCLUSIONS: Our data demonstrate that serum B-type natriuretic peptide levels are positively correlated to neoplastic brain edema in patients with a brain tumor and suggest a possible cerebral source for this phenomenon.