The research progress of using the mammalian olfaction for cancer diagnosis

Abstract

The high mortality associated with lung cancer is mainly due to late diagnoses. Hence, developing inexpensive and simple methods to enable an early diagnosis is very important. The exhalations of patents with cancer are known to contain volatile organic compounds (VOCs). VOCs are therefore regarded to be cancer biomarkers. Recently, several studies have shown that trained dogs can be used to detect cancers with high sensitivity and specificity. Dogs are used to detect drugs or explosives due to their extraordinarily sensitive olfactory systems, which have detection thresholds as low as parts per trillion. These findings suggest that mammals could contribute to the screening and detection of lung cancer. Here we summarize the exhaled-breath detection technologies applied for the diagnosis of lung cancer such as gas chromatography-mass spectrometry and e-Nose. We then focus on the detection of lung cancer using trained dogs. Finally, we describe a new exhaled-breath detection technology called bioelectronic Nose.