Scientists have discovered a new simple breath test that can detect and predict whether an individual is at risk for stomach cancer.
A new technology that analyzes and interprets patients’ “breath prints” – unique patterns of molecules people breathe in and out and reflect conditions in the body – is not only being tested to diagnose stomach cancer, but also monitor patients at high risk for developing the disease. The study, published in the BMJ journal Gut, evaluated the technology, called nanoarray analysis.
It is estimated that roughly 24,590 Americans will be diagnosed with stomach or gastric cancer this year. It is most common among older individuals, with the average age of diagnosis in the US being 69 years old. Since stomach cancer rarely causes symptoms in its early stages, it is often hard to detect. Typically early symptoms, such as poor appetite, weight loss, abdominal pain and nausea, often are mistaken for symptoms of other conditions. Because of this, only one in five stomach cancers in the US are diagnosed before the cancer has spread to other parts of the body. A tool that could detect the disease in its early stages would dramatically improve treatment outcomes in this patient population.
This prompted researchers at Russell Berrie Nanotechnology Institute in Israel to conduct a study, collecting breath samples from 484 people, including 99 who had been diagnosed with stomach cancer but had not received any treatment with chemotherapy or radiotherapy. Professor Hossam Haick, of the Israel Institute of Technology, and colleagues looked into the use of the nanoarray for the early identification of stomach cancer.
The study participants had fasted for 12 hours prior to giving the breath samples. Additionally, participants were tested for infection with Helicobacter pylori infection, an established risk factor for stomach cancer. The team of researchers used gas chromatography-mass spectrometry (GCMS), a technology that measures the level of volatile organic compounds (VOCs) in exhaled breath, to test the first breath sample from each individual. For the second breath sample, a combination of nanoarray analysis and pattern recognition was used.
The GCMS results showed that both patients with cancer and those without the disease had distinctive breath prints. Out of the 130 VOCs identified by GCMS in exhaled breath, levels of eight differed significantly when samples from the gastric cancer group were compared with those from the groups with pre-cancerous changes.
The team found that the nanoarray technology was effectively able to distinguish between breath-print compositions in participants with stomach cancer and those at low and high risk of developing the disease. According to the results, the technique achieved 73 percent sensitivity, 98 percent specificity and 92 percent accuracy.
According to Professor Haick, the attractiveness of this test lies in its noninvasiveness, ease of use and low cost.
Last updated: 4/14/15; 3:25pm EST