An electronic nose distinguishes the exhaled breath of patients with Pleural Malignant Mesothelioma from subjects with professional asbestos exposure

Introduction
Malignant Pleural Mesothelioma (MPM) is a highly aggressive cancer of the pleural surface cells which is mainly caused by asbestos exposure. Electronic noses are recently introduced devices which capture the spectrum of exhaled Volatile Organic Compounds (VOCs) providing a composite biomarker profile (breathprint).We tested the hypothesis that an electronic nose may distinguish exhaled air of patients with MPM from subjects with a similar long-term professional exposure to asbestos without MPM and from healthy controls.

Methods
13 patients with a histology confirmed diagnosis of MPM (age 60.9±12.2 yr), 13 subjects with certified, long-term professional asbestos exposure (age 67.2± 9.8), and 13 healthy subjects without asbestos exposure (age 52.2±16.2) participated in a cross-sectional study. Exhaled breath was collected by a previously described method and sampled by an electronic nose (Cyranose 320). Breathprints were analyzed by canonical discriminant analysis on principal component reduction. Cross-validated accuracy (CVA) was calculated.

Results
Breathprints from patients with MPM were separated from subjects with asbestos exposure (CVA: 80.8%, sensitivity 92.3%, specificity 85.7%). MPM was also distinguished from healthy controls (CVA: 84.6%). Repeated measurements confirmed these results.

Discussion
Pattern recognition of exhaled breath can correctly discriminate patients with MPM from subjects with similar occupational asbestos exposure without MPM and from healthy controls. This suggests that electronic noses may potentilally become a diagnostic tool for MPM.