Selected ion flow tube mass spectrometry analysis of exhaled breath for volatile organic compound profiling of esophago-gastric cancer.

Exhaled breath analysis of volatile organic compounds (VOCs) has great potential in terms of disease diagnosis and measuring physiological response to treatment. In this study, selected ion flow tube mass spectrometry (SIFT-MS) has been applied for the quantification of VOCs in the exhaled breath from 3 groups of patients, viz., those with esophago-gastric cancer, noncancer diseases of the upper gastro-intestinal tract, and a healthy upper gastrointestinal tract cohort. A total of 17 VOCs have been investigated in this study. The concentrations of 4 VOCs, hexanoic acid, phenol, methyl phenol, and ethyl phenol, were found to be significantly different between cancer and positive control groups using the Mann-Whitney U test. Receiver operating characteristics (ROC) analysis was applied for a combination of 4 VOCs (hexanoic acid, phenol, methyl phenol, and ethyl phenol) to discriminate the esophago-gastric cancer cohort from positive controls. The integrated area under the ROC curve (AUC) is 0.91. The results highlight the potential of VOC profiling as a noninvasive test to identify those with esophago-gastric cancer.