Rationale: Exhaled breath contains >1,000 volatile organic compounds (VOCs) which originate from metabolic processes, the environment or drug metabolites. Analyzing the breath VOC profile over time may provide insight into the kinetics of uptake and breakdown of exogenous compounds such as drugs. Aim: This proof-of-concept study explores longitudinal analysis of VOCs in exhaled breath as a means to investigate the washout period of an ingested exogenous compound. Methods: Breath samples were collected in quadruplicate before ingestion and at 30 minute intervals for up to 8 hours after ingestion of a peppermint capsule. Breath was collected using the ReCIVA Breath Sampler and analyzed using Gas Chromatography Mass Spectrometry. The peak areas of five peppermint-related compounds (ɑ-pinene, β-pinene, limonene, eucalyptol and (±)-menthol) were quantified. The mean average and range of % relative standard deviation (%RSD) of peak area was calculated for each compound to assess intra-sample reproducibility. Results: 30 minutes after ingestion of the peppermint capsule the levels of peppermint-related VOCs in breath increased compared to baseline, for example ɑ-pinene increased 28-fold (peak area 1.11E+08 +/- 3.73E+06 SD) compared to baseline (3.88E+06 +/- 2.54E+05 SD). All five VOCs followed a washout curve, returning to baseline levels after 6.5 hours. Replicates demonstrated high intra-sample reproducibility, for example the mean average %RSD of peak area for ɑ-pinene was 8.05. Conclusions: We demonstrate the feasibility of breath biopsy to monitor volatile metabolites related to exogenous compounds in a longitudinal study, for example to non-invasively study the kinetics of drugs inside the body.

There is an urgent need for methods to detect lung cancer earlier. If detected early, over half of lung cancer patients could be cured with existing treatments. Therefore, our greatest opportunity lies in increasing rates of early diagnosis through improved cancer screening. Exhaled breath contains over 1,000 Volatile Organic Compounds (VOCs), which are the products of metabolic activity, hence they directly reflect the current state of cells and represent a valuable source of information about the health of an individual. As the earliest stages of tumor development are characterized by profound changes in cellular metabolic activity, VOCs are potential non-invasive biomarkers for early detection of lung cancer. The LuCID study aims to collect breath samples and evaluate VOCs in exhaled breath as non-invasive biomarkers for early detection of lung cancer.

Introduction: Currently almost 70% of lung cancer patients are diagnosed at late stage when curative treatment is rarely achievable. There is an urgent need for better early detection methods. Changes in cellular activity underlying cancer growth are reflected by cellular metabolites. The LuCID study aims to use the exhaled fraction of these metabolite, volatile organic compounds (VOCs), as non-invasive breath biomarkers for early detection of lung cancer. Methods: LuCID is a multi-centre study (ClinicalTrials.gov ID NCT02612532) evaluating breath VOCs in patients with a clinical suspicion of lung cancer. Using tidal breathing, patients breathe into the ReCIVA Breath Sampler for 7 minutes to collect bronchial enriched and end-tidal breath fractions on stable sorbent tubes for later analysis by GC-MS and Field Asymmetric Ion Mobility Spectrometry (FAIMS, Owlstone Medical Ltd). A classification algorithm will be constructed from chemical spectral data, and undergo internal and external blinded validation to provide a ROC-curve detailing diagnostic accuracy. Results: The LuCID study has recruited 691 patients to date from 21 centres (mean age 67, SD 12.3). In the current population 38% of these patients have lung cancer (of those with lung cancer: 45% early stage 1a-2b, 55% late stage 3a-4). We will present protocol details and baseline data at the ERS meeting. Based on interim results the LuCID study will recruit up to 3000 patients. Conclusions: The LuCID study is evaluating analysis of exhaled biomarkers as a new modality for lung cancer screening. This non-invasive easy to implement test could drastically improve early detection rates reducing lung cancer morbidity and mortality.

Background: There is emerging evidence for the use of exhaled volatile organic compounds (VOCs) in pulmonary disease. A major challenge in the field of breath metabolomics is lack of standardised capturing of breath VOCs (ERS taskforce). Hardware differences between groups prevent pooling of data and adequate comparison between analytical techniques. Methods: The Breathe Free Consortium (www.breathe-free.org) aims to solve this by combining the expertise of over 70 breath researchers with that of engineers and industrial designers in an open source development platform for a breath sampler. Results: Forum discussions resulted in a design that is flexible to match the requirements for a wide range of conditions. The current functional prototype allows sampling of nasal, oral, bronchial, alveolar and mixed breath through pressure and CO2 gating. Fig 1. displays functioning of the device during 5 breath cycles: the blue line indicating CO2%, red indicating exhalation/inhalation pressure and the green line indicating pump activity (pressure gated). Conclusion: The Consortium will be able to present the fully functional Breathe Free Sampler at the ERS in September. This can set a widely accepted standard for breath sampling that is freely available. The resulting pooling of datasets and comparison of different analytical techniques will strongly facilitate the integration of breath analysis into clinical practice.