Exhaled biomarkers in lung cancer

Abstract

Lung cancer is the leading cause of cancer death. Results of therapeutic interventions are particularly discouraging when the disease is discovered in an advanced stage. Early diagnosis is limited by the fact that the disease usually develops asymptomatically and available screening methods do not fulfil the requirements for reliable discrimination between patients with lung cancer and subjects not suffering from the disease. Breath sampling is completely noninvasive and provides a potentially useful approach to screening lung cancer. Exhaled biomarkers contain both volatile and nonvolatile molecules. The profile of volatile organic compounds is different in patients with lung cancer than in control subjects. In exhaled breath condensate, the proteomic profile of breath from cancer patients differs from that of healthy smokers. We reviewed the scientific evidence demonstrating that a unique chemical signature can be detected in the breath of patients with lung cancer and that the exhaled breath biomarker profile could aid clinical decision making.KEYWORDS: Biomarker, electronic nose, exhaled breath, exhaled breath condensate, lung cancer, smell L ung cancer is the leading cause of global cancer death in both males and females. According to the most recent projection of global mortality, by 2030 it will emerge as the third and the fifth leading cause of death in highand middle-income countries, respectively [1,2]. Figures on disease outcome measures are very discouraging as even with the most advanced treatment strategies ,86% of lung cancer patients die within 5 yrs of diagnosis. With early detection and treatment, however, the 5-yr survival rate improves dramatically from 20% in patients with stage III lung cancer to 70% in patients with stage I disease [3]. Researchers, therefore, have sought out screening tests to detect lung cancer in the earliest stages and several promising new approaches have been proposed for this purpose, such as computer-assisted image analysis of chest radiographs, spiral computed tomography (CT) scanning, PCR-based assays of sputum and fluorescence bronchoscopy [4][5][6][7].Breath chemical tests have a broad spectrum of applications ranging from the US Food and Drug Administration-approved exhaled nitric oxide fraction (FeNO) measurement to monitor the effect of anti-inflammatory treatment in asthma, to volatile organic compound (VOC) determination and nonvolatile biomarker profiling in the cooled breath sample called exhaled breath condensate (EBC) [8][9][10][11]. Being completely noninvasive, sampling of the breath allows clinicians and researchers to assess different body functions in a flexible manner. Breath collection can be performed even in very severe patients and also repeated within short intervals. Therefore, breath testing is considered to be a potentially ideal candidate for screening purposes. Besides widely known constituents such as nitrogen, oxygen, carbon dioxide, inert gases and water vapour, exhaled breath also consists of thousands of volatile and nonv...

A rapid method for breath analysis in cystic fibrosis patients

“…For lung diseases diagnostic approaches based on volatile organic compounds (VOCs), including those emitted by pathogenic microorganisms, are considered [2]. These VOCs comprise hydrocarbons, esters, ketones, aldehydes, and alcohols [3].…”

Lung cancer screening

“…For instance, proteomic analysis of plasma, using SELDI-TOF and protein chip technology, has revealed high sensitivity and specificity, with an 8.7-fold excess risk of cancer for CT-screened individuals with elevated SAA protein levels (Cremona et al, 2010). Another new field of research is represented by breathing analysis, using electronic sensors (e-nose) to capture volatile compounds, or to extract genomic and proteomic material from frozen exhaled breath condensation (Horváth et al, 2009). …”

Profiling allergic asthma volatile metabolic patterns using a headspace-solid phase microextraction/gas chromatography based methodology

“…Exhaled breath is a non-invasive, easily performed and rapid sampling, either in the gaseous or condensed state. For example in the gaseous state, the purpose of the present manuscript, there have been studies in asthma [4], cystic fibrosis [5] and lung cancer [6,7].…”