Pilot study for bladder cancer detection with volatile organic compounds using ion mobility spectrometry: a novel urine-based approach.

PURPOSE: Despite many efforts, no reliable urinary marker system has so far shown the potential to substitute cystoscopy. Measuring volatile organic compounds (VOCs) from urine is a promising alternative. VOCs are metabolic products which can be measured from the headspace of urine samples. Previous studies confirmed that the urine of bladder tumor patients has a different VOC profile than healthy controls. In this pilot study, the feasibility of discriminating VOCs from urine of bladder cancer patients from that of healthy control subjects was investigated. Aim of this study was to investigate whether VOC-based diagnosis of bladder cancer from urine samples is feasible using multicapillary column ion mobility spectrometry (MCC/IMS) and to identify potential molecular correlates to the relevant analytes. METHODS: Headspace measurements of urine samples of 30 patients with confirmed transitional cell carcinoma (TCC) and 30 healthy controls were performed using MCC/IMS. In the results of the measurements, peaks showing significant differences between both groups were identified and implemented into a decision tree with respect to achieve group separation. Molecular correlates were predicted using a pre-defined dataset. RESULTS: Eight peaks with significantly differing intensity were identified, 5 of which were highly significant. Using a six-step decision tree, MCC/IMS showed a sensitivity of 90% and specificity of 100% in group separation. CONCLUSION: VOC-based detection of bladder cancer is feasible. MCC/IMS is a suitable method for urine-based diagnosis and should be further validated. The molecular characteristics and metabolic background of the analytes require further workup.

Non-invasive Detection of Bladder Tumors Through Volatile Organic Compounds: A Pilot Study with an Electronic Nose.

BACKGROUND/AIM: Cystoscopy, the standard diagnostic for bladder tumors, is uncomfortable, invasive, and expensive. The available urine-based marker systems all lack accuracy. Measuring volatile organic compounds (VOCs) from urine is a promising alternative. This pilot study evaluates the feasibility of discriminating bladder cancer patients' urine from healthy controls with an electronic nose. MATERIALS AND METHODS: Headspace measurements of urine samples of 30 patients with confirmed transitional cell carcinoma (TCC) and 30 healthy controls were performed with Cyranose 320 calculating Mahalanobis distance and linear discriminant analysis. Histology reports following TUR-BT were correlated with urine findings. RESULTS: After storage at -20°C, Cyranose correctly detected 28/30 already confirmed TCC samples and 26/30 healthy controls (p<0.01), sensitivity 93.3%, specificity 86.7%. Storage at -80°C led to similar results: 28/30 tumor samples and 28/30 control samples were correctly allocated; sensitivity and specificity both 93.3%. CONCLUSION: VOC detection is a promising tool to detect bladder tumors. Further research will test against possible confounders like bacteriuria.