Transcript Slide 1
Analysis of exhaled breath with chromatography or electronic nose. Diagnosis of lung cancer by multifactorial logistic regression analysis Dr.med. Māris Bukovskis 1 2 4, Dr.biol. Gunta Strazda 1 2 3, Dr.med Uldis Kopeika 2 5, Dr.biol.Normunds Jurka 2, Līga Balode 2, Dr. Jevgenija Aprinceva 3, Dr. Ainis Pirtnieks 5, Prof. Immanuels Taivans 2 3 Department of Pulmonology and Allergology, Pauls Stradins Clinical University Hospital, of Experimental and Clinical Medicine, University of Latvia, 3 Faculty of Medicine, University of Latvia, 4 Department of Internal Medicine, Faculty of Medicine, University of Latvia, 5 Department of Thoracic Surgery, Pauls Stradins Clinical University Hospital 1 2 Institute Lung cancer mortality and diagnostic methods • Lung cancer is the leading cancer killer in both men and women and causes more deaths than the next three most common cancers combined (colon, breast and prostate) • 58 - 73% of stage I lung cancer patients suvive 5years compared to 9 - 24% of patients with stage III lung cancer • Available diagnostic methods - nonsensitive (sputum, chest x-ray), expensive (CT) or invasive (FB) Goldstraw P et al. J Thorac Oncol 2007 American Cancer Society Cancer. Facts and Figures 2012 VOC’s in exhaled breath Lung cancer sniffer dogs CBC News Aug 17, 2011 Gordon SM et al. Clin Chem 1985 Machado et al. AJRCCM 2005 Chen X et al. Cancer 2007 Is this so easy? Complex consisting of desorbtion unit, gas chromatograph and mass spectrometer Chromatogram showing multiple peaks representing particular chemical substances Functional principles of electronic nose Relative electric resistance Cyranose 320 ΔRmax Baseline Time (s) Response of 32 sensors to air sample Methods • 475 patients in total, 252 of them lung cancer patients, and 223 patients with different lung diseases and healthy volunteers, were recruited in the study • Collection and sampling of exhaled air by electronic nose (Cyranose 320) • Analysis of “smell prints” by multifactorial regression analysis Results Classification of cases in nonsmokers Lung cancer No cancer Lung cancer No cancer 128 12 PPV 91.4% 5 120 NPV 96.0% Sensitivity 96.2% Specificity 90.6% Classification of cases in smokers Lung cancer No cancer Lung cancer No cancer 114 7 PPV 94.2% 5 84 NPV 94.4% Sensitivity 95.8% Specificity 92.3% Why is this so valuable? • Advantages of exhaled breath analysis by electronic nose: - cheap - easy to do - non-invasive - sufficiently accurate - possible to do in a large number of patients at risk (all smokers > 50 years of age) • Chromatography analysis is valuable for scientific research purposes Thank You for Your Attention! How to sniff out the disease?