A simple test that analyzes the chemical signature of a patient''s exhaled breath could help diagnose stomach cancer and distinguish it from benign gastric conditions.
The breath test will offer an easier screening tool than endoscopy, where a specially trained medical professional examines the inside of the stomach via a tube inserted down the patient''s gullet, and sometimes also retrieves a biopsy sample of the stomach lining.
Scientists at the Technion, the Israel Institute of Technology (Haifa, Israel) used nanomaterial-based sensors to analyze alveolar exhaled breath samples from 130 patients who had undergone endoscopy, and some were biopsied. There were 37 patients who had been diagnosed with stomach cancer, 32 had ulcers, and 61 had less severe stomach complaints. The samples were from patients attending the Anhui Medical University (Hefei, China).
The breath samples were characterized with an array of 14 nanomaterial-based sensors, combined with a statistical pattern recognition algorithm, with the aim of identifying specific patterns, the so-called breath prints for gastric cancer (GC) and nonmalignant gastric conditions, and other subcategories. The sensors included layers of gold nanoparticles with 11 different organic ligands and layers of single-walled carbon nanotubes capped with four different organic overlayers.
The nanomaterial sensors showed an over 90% success rate in distinguishing the patients with stomach cancer from those with more benign complaints. These sensors were more than 90% accurate at distinguishing early from late stage stomach cancers. Chemical analysis found that five volatile organic compounds, 2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene were significantly elevated in patients with GC and/or peptic ulcer, as compared with less severe gastric conditions. The encouraging preliminary results from the study have initiated a multicenter clinical trial with considerably increased sample size to confirm the observed breath prints.
The authors suggested that there is a high demand, especially in the developing world, for a simple and noninvasive test for selecting the individuals at increased risk that should undergo the endoscopic examination. Hossam Haick, PhD, a professor at the Technion and senior author of the study said, "The promising findings from this early study suggest that using a breath test to diagnose stomach cancers, as well as more benign complaints, could be a future alternative to endoscopies, which can be costly and time consuming, as well as unpleasant to the patient." The study was published on March 5, 2013, in the British Journal of Cancer.