GC-MS Techniques Investigating Potential Biomarkers of Dying in the Last Weeks with Lung Cancer

Abstract

Predicting when a patient with advanced cancer is dying is a challenge and currently no prognostic test is available. We hypothesised that a dying process from cancer is associated with metabolic changes and specifically with changes in volatile organic compounds (VOCs). We analysed urine from patients with lung cancer in the last weeks of life by headspace gas chromatography mass spectrometry. Urine was acidified or alkalinised before analysis. VOC changes in the last weeks of life were identified using univariate, multivariate and linear regression analysis; 12 VOCs increased (11 from the acid dataset, 2 from the alkali dataset) and 25 VOCs decreased (23 from the acid dataset and 3 from the alkali dataset). A Cox Lasso prediction model using 8 VOCs predicted dying with an AUC of 0.77, 0.78 and 0.85 at 30, 20 and 10 days and stratified patients into a low (median 10 days), medium (median 50 days) or high risk of survival. Our data supports the hypothesis there are specific metabolic changes associated with the dying. The VOCs identified are potential biomarkers of dying in lung cancer and could be used as a tool to provide additional prognostic information to inform expert clinician judgement and subsequent decision making.

Village Settlements in Mountainous Tropical Areas, Hotspots of Fecal Contamination as Evidenced by Escherichia coli and Stanol Concentrations in Stormwater Pulses

“… The quantification was achieved with a five-point internal calibration curve (0.1, 0.3, 0.5, 0.7, and 1 ppm) of stanol standards with a constant internal standard concentration at 0.5 ppm. To ensure the absence of potential contaminants and to verify system performance during GC–MS measurements, we analyzed two to five blank samples (empty vials) when beginning the GC–MS sequence, and we ran the 5-point internal calibration curve of stanol standards at the start, middle, and end of each GC–MS sequence (one sequence = 20 samples). A blank was also analyzed after each real sample during the GC–MS sequence.…”

The role of nanoparticles in non‐invasive electrochemical immunosensor technology and recent developments

“…Biomarkers found in biofluids, tissues, and organs in the human body allow the evaluation of a medical condition by helping to detect or monitor a disease [16]. Biomarker detection, which is of vital importance, is currently used in various known analytical methods such as enzyme‐linked immunosorbent assay‐based (ELISA) [17], surface plasmon resonance (SPR) [18], polymerase chain reaction (PCR) [19], and gas chromatography‐mass spectrometry (GC‐MS) [20]. However, the mentioned methods have some limitations such as requiring complex sample preparation, not being suitable for on‐site monitoring, and requiring expert analysts [21].…”

Breathome discriminate Ischemic Heart Disease

“…Exhaled air analysis has been performed in patients with different pathologies including chronic obstructive lung disease, cancer, asthma, lung cancer, diabetes, arthritis, heart failure, gastric cancer, chronic kidney disease, colorectal cancer, hepatocellular carcinoma, malignant pleural mesothelioma, bladder cancer, pancreatic ductal adenocarcinoma, gastro-oesophageal cancer, peritonitis-shock, head and neck squamous cell carcinoma, multiple sclerosis, and Parkinson's disease [8,9,[18][19][20][21][22][23][24][25][26][27]10,[28][29][30][31][32][33][34][35][36][37]11,[38][39][40][41][42][43][44][45][46][47][12][13][14][15][16][17].…”