Analysis of human breath samples of lung cancer patients and healthy controls with solid-phase microextraction (SPME) and flow-modulated comprehensive two-dimensional gas chromatography (GC × GC)

Abstract

This paper reports the use of chromatographic profiles of breath volatiles to determine disease markers in lung cancer patients and healthy volunteers. The volatile fraction was isolated by headspace solid-phase microextraction (HS-SPME) and analyzed by flow-modulated comprehensive two-dimensional gas chromatography and flame ionization (GC × GC-FID). Following the experiments, collected data were transformed, and partial least-squares discriminant analysis (PLS-DA) as well as Mann–Whitney Test were carried out to model the data and discover breath metabolites with a significant concentration difference between patients and healthy subjects. Using the abovementioned method, lung cancer patients and healthy controls could be correctly distinguished based on metabolic VOCs abnormality in human breath. Five potential target compounds including acetone, isoprene, methanol, pentane and propanol were identified. Lung cancer patients show higher concentrations of propanol (7415.3 ng L⁻¹), acetone (1811.6 ng L⁻¹) and methanol (225 ng L⁻¹) compared with those of healthy volunteers (1975.3 ng L⁻¹, 579.9 ng L⁻¹, 76.8 ng L⁻¹, respectively). In addition, there is no significant relationship between breath VOCs and gender or body mass index (BMI). This approach will facilitate the comparison of complex breath VOC profiles and diseases. These findings may offer valuable and reliable information for the early diagnosis and prognosis of lung cancer.