Recent advances in breath-based volatile compounds analysis by various analytical techniques for screening of lung cancer disease

Lung cancer remains a major cause of cancer-related death as it is primarily diagnosed at an advanced stage, and treatments for recovery from the disease are limited. Although traditional screening techniques including low-dose computed tomography and chest radiography are available, the persistent high mortality emphasized the need for an alternative screening technique for the detection of early-stage lung cancer. However, diagnosis at the benign tumor stage is challenging because of the non-specific physical symptoms of lung cancer at the very beginning of the disease. Breath analysis for the detection of lung cancer-specific volatile metabolites emerged as a simple and alternative screening technique for lung cancer disease. To monitor the volatile metabolites, solid-phase microextraction (SPME) was widely utilized as a potential sample preparation technique for non-invasive distinguishing between lung cancer and healthy control individuals. Researchers integrated the sample preparation tools with the gas chromatography-mass spectrometer for monitoring trace levels of breath markers associated with disease. Several analytical techniques including electronic nose, were utilized to detect the odour patterns in lung cancer patients. In this review article, we summarized the recent advances in sample preparation techniques, especially focusing on the SPME technique for the non-invasive screening of lung cancer. Finally, we discussed the various advantages and disadvantages of the breath analysis techniques for volatile metabolites analysis. Future perspective for breath tests to discriminate between lung cancer and control individuals also have been described in this article.