Volatile signature for the early diagnosis of lung cancer

Abstract

Exhaled breath contains hundreds of volatile organic compounds (VOCs). Several independent researchers point out that the breath of lung cancer patients shows a characteristic VOC-profile which can be considered as lung cancer signature and, thus, used for diagnosis. In this regard, the analysis of exhaled breath with gas sensor arrays is a potential non-invasive, relatively low-cost and easy technique for the early detection of lung cancer. This clinical study evaluated the gas sensor array response for the identification of the exhaled breath of lung cancer patients. This study involved 146 individuals: 70 with lung cancer confirmed by computerized tomography (CT) or positron emission tomography-(PET) imaging techniques and histology (biopsy) or with clinical suspect of lung cancer and 76 healthy controls. Their exhaled breath was measured with a gas sensor array composed of a matrix of eight quartz microbalances (QMBs), each functionalized with a different metalloporphyrin. The instrument produces, for each analyzed sample, a vector of signals encoding the breath (breathprint). Breathprints were analyzed with multivariate analysis in order to correlate the sensor signals to the disease. Breathprints of the lung cancer patients were differentiated from those of the healthy controls with a sensitivity of 81% and specificity of 91%. Similar values were obtained in patients with and without metabolic comorbidities, such as diabetes, obesity and dyslipidemia (sensitivity 85%, specificity 88% and sensitivity 76%, specificity 94%, respectively). The device showed a large sensitivity to lung cancer at stage I with respect to stage II/III/IV (92% and 58% respectively). The sensitivity for stage I did not change for patients with or without metabolic comorbidities (90%, 94%, respectively). Results show that this electronic nose can discriminate the exhaled breath of the lung cancer patients from those of the healthy controls. Moreover, the largest sensitivity is observed for the subgroup of patients with a lung cancer at stage I.

Porphyrins for olfaction mimic: The Rome Tor Vergata approach

“…Some of the lung cancer patients were also measured over a period of time after the tumor resection [38]. This result was corroborated by successive investigations aimed at extending the studied cases, introducing comorbidities such as the Chronic Obstructive Pulmonary Disease and metabolic conditions, such as diabetes, obesity and dyslipidemia [39,40]. Figures 3a and 3b show the relevant multicomponent analysis scores plot related to the first two literature results.…”

Clinical contributions of exhaled volatile organic compounds in the diagnosis of lung cancer

“…However, none of the 14 VOC we measured seemed to be a promising biomarker of early disease. The combined measurement of cyclohexane and xylene may increase the sensitivity of early cancer detection as previously demonstrated in the studies using eNose or colorimetric sensor array [14,15], a hypothesis we could not validate definitively because of the small number of patients presenting with early-stage cancer. The concentrations of cyclohexane and xylene increased as the lung cancers progressed, and decreased following successful treatments of 6 patients, suggesting that these VOC could monitor the progression of SCLC and NSCLC as well as the outcome of treatment.…”

Integrating exhaled breath diagnostics by disease-sniffing dogs with instrumental laboratory analysis

“…The ‘breath aerosol’ is comprised of small liquid particles enriched in the semi-volatiles, dissolved ionic material, bacteria, and larger organic compounds. Although much attention so far for cancer detection by breath analysis has been on the collection and analysis or on-line analysis of the volatiles (Filipiak et al 2014, Schroeder 2015, Gasparri et al 2016, Schallschmidt et al 2016), we believe that the semi-volatile constituents of the breath aerosol should be given more attention for two reasons. First, collection of the aerosols in breath can (via filtration, adsorption, or absorption) can be simpler than collecting the gas-phase with a focus on the volatiles.…”