A noninvasive exhaled breath test may be able to accurately diagnose patients with early esophagogastric cancer (OGC) in the clinical setting, according to a study published in JAMA Oncology.1
Oesophagogastro duodenoscopy (OGD) is a procedure to diagnose OGC, but it is highly invasive and expensive. Furthermore, patients with OGC tend to be asymptomatic and only once the disease has progressed to advanced stages do patients experience classic alarm symptoms. Such symptoms can include dysphagia and odynophagia, but even after they are diagnosed they have poor sensitivity and specificity for OGC.
For this diagnostic validation study, researchers enrolled 335 participants, of whom 163 had OGC and 172 were assigned to the control group. Investigators collected breath samples to analyze volatile organic compounds (VOCs) — compounds emitted from the human body that have been previously thought to be associated with lung, breast, and bladder cancers. Eligible patients had upper gastrointestinal symptoms, were potentially undergoing endoscopy or surgery, and, for patients in the cancer arm, only patients with nonmetastatic esophagogastric adenocarcinoma who had not received neoadjuvant therapy were included.
Samples were evaluated using the selected ion flow tube mass spectrometry (SIFT-MS) analysis and the risk of OGC was calculated using a previously generated 5-VOC model (butyric acid, pentanoic acid, hexanoic acid, butanal, decanal) and compared with histopathology-determined diagnoses.
The generated predictive probabilities by the 5-VOC model were used to create a receiver operator characteristic curve, with good diagnostic accuracy, area under the curve of 0.85. This translated to a sensitivity and specificity of 80% and 81%, respectively, in regards to OGC diagnosis.
The authors concluded that “this study shows the potential of breath analysis in noninvasive diagnosis of OGC in the clinical setting. The next step is to establish the diagnostic accuracy of the test among the intended population in primary care where the test will be applied.”
- Marker SR, Wiggins T, Antonowicz S, et al. Assessment of a noninvasive exhaled breath test for the diagnosis of oesophagogastric cancer [published online May 17, 2018]. JAMA Oncol. doi: 10.1001/jamaoncol.2018.0991