High N-Terminal Pro-B-Type Natriuretic Peptide: A Biomarker of Lung Cancer?

Background: The level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) is affected by many known factors. Our study aimed to evaluate whether other factors, in particular lung cancer, could be responsible for an increase in NT-proBNP levels in a population with no known risk factors for elevated NT-proBNP. Patients and Methods: This study was based on the RIABO (Recueil de l'Ischemie au Bloc Operatoire) database, a single-center registry that prospectively records in elective noncardiac surgery. Patients aged > 75 years and those presenting with 1 or more known risk factors for high NT-proBNP were excluded. Patients were divided into 2 groups according to preoperative NT-proBNP levels: (>= 125 pg/mL or < 125 pg/mL). Results: Between October 2005 and February 2007, 439 patients were eligible for inclusion. Among 35 patients with lung cancer, 26 (74%) had elevated NT-proBNP (>= 125 pg/mL), versus 9 (26%) with NT-proBNP < 125 pg/mL (P < .0001). By multivariate analysis, the presence of lung cancer was an independent risk factor for a level of NT-proBNP >= 125 pg/mL (odds ratio, 7; 95% CI, 2.9-17; P < .0001). We also observed an independent relationship between NT-proBNP >= 125 pg/mL and age, female sex, smoking status, and C-reactive protein levels. Conclusion: In our study, patients with lung cancer were 7 times more likely to have elevated NT-proBNP (>= 125 pg/mL). The presence of lung cancer should therefore be taken into account when interpreting NT-proBNP levels. Further studies are warranted to explore the diagnostic value of this marker in lung cancer and to identify the cause of the elevation.