Analysis of exhaled breath for screening of lung cancer patients

Abstract

The fast development of analytical techniques in the field of gas analysis can be compared to that of computers during the last two decades. Not only speed but also sensitivity of analysis has been greatly improved, sometimes by a factor of 100 or more. This technological development has fostered the analysis of exhaled breath. Since this can be done in real-time, very fast biological processes can be monitored. Also simulation and modelling of haemodynamics and lung mechanics become possible. During the next decade we will see miniaturized equipment (of the size of a cigarette box) appear. Here we review and illustrate the rich diversity of compounds observed in exhaled breath with a particular focus on lung cancer patients. Each of the many volatile compounds has its own particular biochemical background, and cell types with different genetic background have been shown to have a different pattern of released and consumed volatile compounds. Nevertheless we still lack an understanding, if and how genetic alterations, which are seen as the underlying cause of the transformation process, control the VOC phenotype observed in patients or cancer cell lines. The concentration pattern of volatile compounds in exhaled breath may be used in the future for phenotyping individuals in large-scale screening approaches. Also changes in VOC patterns may provide disease-relevant information (e.g. on the activity of metabolizing enzymes). Future applications will also include the follow-up of exogenous compounds which are ingested or inhaled as drugs, food components or components in cigarette smoke and metabolic products of these compounds. © 2010 Springer.