Detection of volatile organic compounds in exhaled breath for early diagnosis of lung cancer

Objective: To investigate the application value of detecting volatile organic compounds (VOCs) in exhaled breath for the early diagnosis of lung cancer. Methods: The changes of VOC type and content in exhaled breath from the patients with lung cancer and the healthy controls were analyzed by gas chromatography-mass spectrometry (GC-MS), then the volatile markers were screened for the early diagnosis of lung cancer. Results: Twenty-four VOCs were identified from the exhaled breath of lung cancer patients, among which the contents (average peak areas) of 3-hexene-2- ketone and 3-hydroxy-2-butanone were significantly higher than those of the healthy control group (both P < 0.05). The average peak areas of these two VOCs in advanced lung cancer patients (stage III and IV were significantly higher than those in early-stage lung cancer patients (stage I and II) (all P < 0.05), which both were significantly higher than those in the healthy control group (all P < 0.05). Compared to non-small cell lung cancer, the average peak area of 3-hydroxy-2-butanone was significantly higher than that in small cell lung cancer (P < 0.05). There was no significant difference in the content of 3-hexene- 2-ketone between the patients with small cell lung cancer and the ones with non-small cell lung cancer. Conclusion: The contents of 3-hexene-2-ketone and 3-hydroxy-2-butanone are significantly increased in the exhaled breath of patients with lung cancer, suggesting that the two VOCs can be applied as volatile markers and the detection of exhaled VOCs by GC-MS may be a promising method for early diagnosis of lung cancer in the future.