Breath Test Developed to Diagnose Esophageal and Gastric Cancer

A breath test has been devised that can help doctors diagnose the early signs of esophageal and gastric cancer in minutes and the test can discriminate between malignant and benign esophageal cancer in patients for the first time.

Esophageal and gastric malignancies account for 15% of cancer-related deaths globally and both cancers are usually diagnosed in the advanced stages because they rarely cause any noticeable symptoms when they first develop. As a result, the long-term survival rate is 13% for esophageal cancer and 15% for gastric cancer in the UK.

A team of scientists led by those at Imperial College London (UK) analyzed breath samples of 210 with esophageal and gastric cancer patients using the breath test from 2011 to 2013. Patients who are at risk of developing these cancers and those who had benign tumors were also tested. To take the test, patients breathe into a device similar to a breathalyzer which is connected to a bag. The compounds in their exhaled breath are analyzed by a selected ion flow tube mass spectrometer.

The test looks for chemical compounds in exhaled breath that are unique to patients with esophageal and gastric cancer. The cancers produce a distinctive smell of volatile organic compounds (VOC), chemicals that contain carbon and are found in all living things, which can help doctors detect early signs of the disease. The team was able to identify for the first time the number of VOCs in breath samples by using a Profile-3 Selected Ion Flow Tube Mass Spectrometry instrument, an analytical apparatus used to identify what chemicals are present in a sample.

Twelve VOCs: pentanoic acid, hexanoic acid, phenol, methyl phenol, ethyl phenol, butanal, pentanal, hexanal, heptanal, octanal, nonanal, and decanal were present at significantly higher concentrations in the cancer groups than in the non-cancer controls This quantitative technology identified VOCs that were present at significantly higher concentrations in patients with esophageal and gastric cancer than in non-cancerous patients. The scientists say that the results could be used to set a biomarker, a biological feature used to measure the presence or progress of a disease.

George B. Hanna, FRCS, PhD, the lead author of the study said, “Esophageal and gastric cancers are on the rise in the UK with more than 16,000 new cases diagnosed each year. The current method for detecting these cancers is expensive, invasive and a diagnosis is usually made at a late stage and often the cancer has metastasized. This makes it harder to treat and results in poor long-term survival rates. Our breath test could address these problems because it can help diagnose patients with early nonspecific symptoms as well as reduce the number of invasive endoscopies carried out on patients, which often lead to negative results. Diagnosis at an early stage could give patients more treatment options and ultimately save more lives.” The study was published on June 25, 2015, in the journal Annals of Surgery.

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Imperial College London