Volatile organic metabolites identify patients with gastric carcinoma, gastric ulcer, or gastritis and control patients

Abstract

Background: Gastric cancer ranks 4th among the most common cancers worldwide, and the mortality caused by gastric cancer is 2nd only to lung cancer. Gastric cancer shows a lack of specific symptoms in its early stages. In addition, its clinical symptoms often do not match the corresponding stage. Upper gastrointestinal endoscopy with biopsy is the gold standard for the diagnosis of gastric cancer because of its high accuracy. However, this operation is invasive, patient compliance is poor, and high demands for medical staff and equipment are typical of this procedure. Recent studies have demonstrated a connection between specific breath volatile organic compounds (VOCs) and various forms of cancers.

Methods: We collected expired air from patients with gastric cancer, chronic atrophic gastritis or gastric ulcers as well as from healthy individuals. Solid-phase microextraction, gas chromatography-mass spectrometry and principal component analysis statistics were applied to identify potential biomarkers of gastric cancer among VOCs.

Results: Fourteen differential metabolites were annotated using the NIST 11 database, with a similarity threshold of 70%. Currently, the metabolic origin of VOCs remains unclear; however, several pathways might explain the decreasing or increasing trends that were observed.

Conclusions: The results of this study demonstrate the existence of specific VOC profiles associated with patients with carcinoma. In addition, these metabolites may contribute to the diagnosis and screening of patients with carcinoma.

Keywords: Gastric carcinoma; Gastric ulcer; Gastritis; VOCs.

Fig. 1

a PCA score plot: gastric carcinoma patients vs controls. b OPLSDA score plot: gastric carcinoma patients vs controls: (4 components, R2X = 0.507, R2Y = 0.676, and Q2 = 0.439). c PLSDA validation plot intercepts: gastric carcinoma patients vs controls R2 = (0.0, 0.164); Q2 = (0.0, − 0.161)

Fig. 2

a PCA score plot: gastric ulcer vs gastric carcinoma patients. b OPLSDA score plot: gastric ulcer vs gastric carcinoma patients (3 components, R2X = 0.535, R2Y = 0.616, and Q2 = 0.423). c PLSDA validation plot intercepts: gastric ulcer vs gastric carcinoma patients R2 = (0.0, 0.167); Q2 = (0.0, − 0.163)

Fig. 3

a PCA score plot: gastritis patients vs gastric carcinoma patients. b OPLSDA score plot: gastritis patients vs gastric carcinoma patients (4 components, R2X = 0.381, R2Y = 0.695, Q2 = 0.542). c PLSDA validation plot intercepts: gastritis patients vs gastric carcinoma patients R2 = (0.0,0.141); Q2 = (0.0, − 0.221)