Heptane And Toluene In The Exhaled Breath Of Lung Cancer Patients

Research purpose:Through the study of heptane and toluene in the exhaled gas of lung cancer patients,the application value of these two gases in lung cancer detection was evaluated,so as to provide help and guidance for the non-invasive screening of lung cancer in clinical practice.Methods:1.The subjects included in this study were the inpatients in the department of respiratory medicine of Yuhuangding hospital,Yantai on January 1,2018,solstice on June 30,2018,including 60 patients who were diagnosed as primary lung cancer through bronchoscopy or percutaneous lung biopsy for the first time and confirmed by pathological examination.60 cases were diagnosed as benign pulmonary lesions?including community acquired pneumonia,tuberculosis?.60 people without respiratory disease?health group?were selected from the physical examination center.2.Gas samples were collected from the eligible patients according to strict requirements,and the levels of heptane and toluene in the exhaled gas of the above three groups were detected by GC-MS equipment.3.SPSS 23.0 statistical software was used to analyze the data,and the measurement data were in line with the normal distribution,represented by mean standard deviation?`±s?.Independent sample t test was used for inter-group comparison,and one-way anova and Lsd-t test were used for inter-group comparison;Peak area was compared between groups,mann-whitney U test was used for comparison between the two groups,and kruskal-wallis H test was used for comparison between the three groups.The rate or composition ratio of counting data was expressed,and the chi-square test was used for comparison between groups.P<0.05 was considered statistically significant.Results:There was no significant difference in clinical data among lung cancer group,benign pulmonary disease group and healthy group.The peak figure of heptane and toluene in the exhaled gas showed that there were statistically significant differences in the exhaled gas peak rate and area of heptane and toluene among the three groups?P<0.05?.There was no significant difference in the area of heptane and toluene peak in the exhaled gas of patients with different pathological types of lung cancer?P>0.05?.There were statistically significant differences in peak exhalation rate and peak area of heptane in patients with different clinical stages of lung cancer?P<0.05?,while there were statistically significant differences in peak exhalation rate of toluene in patients with different clinical stages of lung cancer?P<0.05?,but no statistically significant differences in peak exhalation area?P>0.05?.According to the binary Logistic regression model,the prediction probability of lung cancer of the subjects was calculated as P by using such factors as whether heptane and toluene peak,etc.P=e^Logit?p?/(1+e ^Logit?p?)?Logit?p?=-2.12+2.35*X1+2.19*X2;Heptane with peak X1=1,off-peak X1=0;Toluene with peak X2=1 and without peak X2=0?;The accuracy of the prediction was 0.845.Conclusion:1.The peak exhalation rate and area of heptane and toluene in the exhaled gas of lung cancer patients were higher than that of the benign lung disease group and the healthy group.Heptane and toluene may be the characteristic volatile organic compounds?VOCs?of lung cancer patients,providing a reference for clinical diagnosis of lung cancer.2.The peak rate of heptane and toluene in the exhaled gas of patients with advanced lung cancer was higher than that of patients with early stage lung cancer.When these two gases were used as biomarkers to screen patients with lung cancer,the detection rate of patients with advanced lung cancer was higher than that of patients with early stage lung cancer.The heptane peak area of patients with advanced lung cancer was higher than that of patients with early stage lung cancer,which may have certain guiding significance in monitoring the progress of lung cancer and evaluating the prognosis.3.According to the prediction model P=eLogit?P?/?1+eLogit?P??,Logit?P?=-2.12+2.35*X1+2.19*X2;Heptane with peak X1=1,off-peak X1=0;Toluene with peak X2=1 and without peak X2=0),the prevalence of lung cancer in suspected patients can be effectively predicted.