Significant different volatile biomarker during bronchoscopic ion mobility spectrometry investigation of patients suffering lung carcinoma

Exhaled breath of patients suffering non-small bronchial carcinoma contains volatile organic compounds (VOC) different from healthy people. VOCs could be detected using ion mobility spectrometry down to the pg/L range even in air directly. To date, the origin of the different VOCs found is insecure. Such VOCs could be a direct product of the metabolism of the tumor or relatable to mostly present co-factors like infections or necrosis or a reaction of the human organism to the tumor (e.g. oxidativ stress). In the present study the breath of 19 patients suffering from confirmed NSCLC (non-small-cell lung carcinoma) with different histological types was investigated. In all cases flexible video-chip bronchoscopy was realized. Before taking samples for histological investigations in the lung on both main bronchi, samples of air were taken using a polytetrafluoroethylene (PTFE or Teflon) tube as catheter directly from the working channel of a bronchoscope and connected directly to the inlet of the ion mobility spectrometer. The measurement was started immediately. In total, 72 common peaks could be identified. 5 Peaks were significantly varying between the tumor site and the collateral lung. Considering adenocarcinoma, one peak separates both sites clearly and was relatable to the dimer of n-Dodecane. Two peaks were found on squamous cell carcinoma and relatable to 2-Butanol or 2-Methylfuran and Nonanal. The sensitivity, specificity, positive and negative predictive values were, for adenocarcinoma 100%, 75%, 80% and 100%, respectively – for squamous cell carcinoma 78%/78%, 67%/78%, 70%/80% and 75%/88%, for 2-Butanol and Nonanal respectively. Therefore, VOCs obtained from bronchoscopic sampling of breath could be detected using ion mobility spectrometry. The present study suggests that lung carcinoma with different histology will be represented by different volatile analytes.