July 20, 2018
Improvement in diagnostic models and symptom recognition would aid early detection of pancreatic cancer.
Measuring exhaled-breath volatile organic compounds (VOCs) has shown promise as a potential method for diagnosing patients with pancreatic cancer, according to a study published in the British Journal of Surgery.
One of the greatest challenges in pancreatic cancer is early detection; as symptoms frequently overlap with other benign conditions, only 15% to 20% patients have curable disease at the time of diagnosis. There is a need for improvement in diagnostic models, symptom recognition, and predictive biomarkers.
For this study, investigators enrolled 68 patients (25 with pancreatic cancer, 42 with no cancer) to their development cohort and 64 to their validation cohort (32 with pancreatic cancer, 32 with no cancer). In the development cohort, researchers analyzed the exhaled breath of participants using gas chromatography mass spectrometry to identify the difference in VOC concentrations among patients with cancer compared with the no-cancer controls.
Overall, 66 VOCs were identified; 22 were excluded from further study as they were found in high concentrations in background air or were considered to be at a low likelihood of being produced endogenously. Of the remaining 44 VOCs, 12 were found to be significantly different among patients with pancreatic adenocarcinoma compared with patients without cancer.
The concentration of 5 VOCs were considerably higher among cancer patients: formaldehyde, acetone, acetoin, undecane, and isopropyl alcohol. Seven VOCs (pentane,n-hexane, 1-butanol, 1-[methylthio]-propane, benzaldehyde, tetradecane, amylene hydrate) were found in lower concentrations among patients with cancer.
A receiver operating characteristic (ROC) curve analysis of the significant volatile compounds and the validation cohort showed good discrimination, resulting in an area under the curve of 0.736 (sensitivity, 81%; specificity, 58%) for differentiating cancer from no cancer, and 0.744 (sensitivity, 70%; specificity, 74%) for differentiating adenocarcinoma from no cancer.
Breath VOC-analysis may be a useful tool in distinguishing patients with pancreatic cancer from patients without the disease. The authors concluded that the “final application of breath testing in the patient care pathway will depend on test sensitivity and specificity in large multicenter clinical trials, and its performance in early pancreatic cancer and high-risk groups.”
Markar SR, Brodie B, Chin ST, Romano A, Spalding D, Hanna GB. Profile of exhaled-breath volatile organic compounds to diagnose pancreatic cancer[published online July 18, 2018]. Br J Surg. doi: 10.1002/bjs.10909