Exhaled Gas Extractive Electrospray Ionization Mass Spectrometry Detection For Clinical Value To Diagnosis Of Lung Cancer

Objectives：At present, the study on Exhaled gas becomes deeper, and there are also a widerange of methods for it. In this study, we applied detection method which isinnovative of EESI combined with LTQ-MS to detect the exhaled gas from patients ofLung Cancer, Pulmonary infection and the normal adults. Finding out iconiccomposition among three groups of samples based on the composition analysis ofexhaled gas from three groups above-mentioned, and analyze the relationshipbetween Tumor Marker and iconic gas composition of the lung cancer patients.Methods：We chose the subjects rigorously and divided into three groups, which containsforty lung cancer patients, twenty pulmonary infection patients and twenty normaladults. Applying mixed expiratory sampling to take gas samples, we should useTedlar bags to fill the exhaled gas from each subject and proceed EESI-MS detectionwithin three hours.Results：We found that the samples under ventilation are closed to living samplesobtained from mass spectrometer and could obviously see the signal intensity isstronger under ventilation than in closed environment by comparing massspectrogram of exhaled gas under ventilation with which is in airtight environment ofthe same subject.The three-dimensional scores plot which is from PCA of lung cancer, pulmonaryinfection and normal groups prompted us lung cancer group could be effectivelydistinguished from pulmonary infection and normal groups, and there is no obviousdifference between pulmonary infection and normal groups. There is a statisticalsignificance in the differences of C2H8N2, C4H6N4, C2H7N9, C4H15N8, C15H17,C14H13N4and C13H34N6in three groups by PCAand SPSS analysis.The three-dimensional scores plot could not distinguish effectively positivepatients from negative patients, which prompted there is no any relationships between exhaled gas composition and five serum tumor markers by PCA analysis of exhaledgas from the lung cancer patients of serum tumor markers CEA, CA-125, CA-199,NSE, positive and negative Cyfra21-1.Conclusions：(1)The signal intensity of collected gas is stronger under ventilation than inclosed environment and is closer to the detection of living samples.(2)C2H8N2, C4H6N4, C2H7N9, C4H15N8, C15H17, C14H13N4and C13H34N6are thespecific components of lung cancer.(3)There is no relationship between exhaled gas and serum tumor markers CEA,CA-125, CA-199, NSE, and Cyfra21-1.