Electronic Nose as a Novel Method for Diagnosing Cancer: A Systematic Review

Abstract

Cancer is fast becoming the most important cause of death worldwide, its mortality being mostly caused by late or wrong diagnosis. Novel strategies have been developed to identify early signs of cancer in a minimally obtrusive way, including the Electronic Nose (E-Nose) technology, user-friendly, cost- and time-saving alternative to classical approaches. This systematic review, conducted under the PRISMA guidelines, identified 60 articles directly dealing with the E-Nose application in cancer research published up to 31 January 2020. Among these works, the vast majority reported successful E-Nose use for diagnosing Lung Cancer, showing promising results especially when employing the Aeonose tool, discriminating subjects with Lung Cancer from controls in more than 80% of individuals, in most studies. In order to tailor the main limitations of the proposed approach, including the application of the protocol to advanced stage of cancer, sample heterogeneity and massive confounders, future studies should be conducted on early stage patients, and on larger cohorts, as to better characterize the specific breathprint associated with the various subtypes of cancer. This would ultimately lead to a better and faster diagnosis and to earlier treatment, possibly reducing the burden associated to such conditions.

Discovery of Volatile Biomarkers for Bladder Cancer Detection and Staging through Urine Metabolomics

“…The investigation of candidate volatile biomarkers for urological cancers has become of great interest over the last years due to a study by Willis et al which showed that dogs were able to detect BC in urine samples by sniffing [ 22 ]. Based on this observation, several researchers have focused on the application of electronic noses, i.e., devices that mimic the human olfactory system, for analysis of volatile metabolites present in urine headspace of cancer patients and cancer-free individuals [ 23 ]. Studies performed in urine of BC patients have demonstrated that electronic noses using different technologies can detect BC with sensitivity ranging from 60 to 93% and specificity from 67 to 93% [ 24 , 25 , 26 ].…”

eNose analysis for early immunotherapy response monitoring in non-small cell lung cancer

“…ENoses have been designed for classification of VOCs by pattern recognition, which can be used for probabilistic assessment of disease states. Promising results have been observed in different diseases, particularly in the field of respiratory medicine [12,13]. Recently, De Vries et al showed that exhaled breath analysis by eNose can be used before start of treatment to identify NSCLC patients that show progressive disease (PD) to anti-PD-1 therapy with 100% specificity.…”

Sniffer dogs can identify lung cancer patients from breath and urine samples

“…Using an electronic nose for diagnosing cancer had been used for a variety of different cancers with lung cancer being the most intensively studied. Bladini C et al provided an extensive overview on the variety of cancers studied as well as the current technically available systems discussing their advantages and disadvantages [ 21 ]. The authors identified 37 articles dealing with commercial and non-commercial electronic nose systems published until January 2020.…”

“…Among these Li et al [ 22 ] used an array of 14 different sensors in combination with an in depth data pre-processing and, among others, support vector machine processing for classification, reaching a sensitivity of 91.6% and a specificity of 91.7%. The authors concluded that these studies displayed satisfying results with different technologies, which could be used in clinical practice with desirable technological development [ 21 ].…”