A test measuring the amounts of 5 different chemicals in the breath could assist in the detection of stomach and esophageal cancers, according to results from a multicenter blinded validation study. These results were presented at the 2017 European Cancer Congress.1
Both stomach and esophageal cancer are typically diagnosed at late stages as symptoms are ambiguous. As a result, 5-year survival for these cancers is 15%
This study showed 85% accuracy in the diagnosis of stomach and esophageal cancer in more than 300 patients.
“At present the only way to diagnose esophageal cancer or stomach cancer is with endoscopy. This method is expensive, invasive, and has some risk of complications,” explained Sheraz Markar, PhD, a National Institute for Health Research Clinical Trials Fellow from Imperial College, London, England.
“A breath test could be used as a noninvasive, first-line test to reduce the number of unnecessary endoscopies. In the longer term this could also mean earlier diagnosis and treatment, and better survival.”
This study assessed whether differences in breath chemicals could be used as a diagnostic test for stomach and esophageal cancers. Previous research suggested differences in butyric acid, pentanoic acid, hexanoic acid, butanal, and decanal between patients with stomach or esophageal cancers and patients with upper gastrointestinal symptoms with no cancer.
Researchers collected breath samples from 335 patients at 3 different hospitals in London. Of these patients, 163 had diagnoses of stomach or esophageal cancer, and 172 patients demonstrated no evidence of cancer when they underwent endoscopy.
Researchers used selected ion flow-tube mass spectrometry, which measures small quantities of chemicals in mixtures of gases, to analyze all samples.
The test was 85% accurate at detecting a distinct chemical signature in the breath samples of patients with cancer. The test had 80% sensitivity and 81% specificity.
“Because cancer cells are different to healthy ones, they produce a different mixture of chemicals. This study suggests that we may be able detect these differences and use a breath test to indicate which patients are likely to have cancer of the esophagus and stomach, and which do not,” Markar explained.
“However, these findings must be validated in a larger sample of patients before the test could be used in the clinic.”
1. Markar S, Wiggins T, Antonowicz S, Lagergren J, Mughal M, Hanna G. Breath volatile organic compound analysis for the diagnosis of oesophago-gastric cancer; multi-centre blinded validation clinical trial. Paper presented at: European Cancer Congress 2017; January 27-30, 2017; Amsterdam, Netherlands. Abstract 6LBA.