Early detection of upper gastrointestinal cancer may someday be as simple as sniffing out a person's breath, a new study in the United Kingdom revealed.
Doctors typically diagnose stomach cancer or esophageal cancer through endoscopy, a process that involves easing a tube with camera down the digestive tract of a patient.
Such upper gastrointestinal cancers tend to be diagnosed late because symptoms are ambiguous. Statistics show that late diagnosis has led to a five-year survival rate of 15 percent.
Now, a simple breath test has shown positive results in the detection of upper gastrointestinal cancer.
Researchers from Imperial College London designed a process that analyzes a certain "chemical signature" that appears in esophageal cancer and stomach cancer patients.
In a clinical trial, scientists tested five volatile organic compounds (VOCs) - butyric acid, hexanoic acid, pentanoic acid, butanal, and decanal - against the breath of more than 300 patients.
Of the participants, 163 patients had been diagnosed with upper gastrointestinal cancer while 172 patients exhibited no evidence of cancer during endoscopy.
After using selected ion flow-tube mass spectrometry to analyze the chemical samples, researchers found an 85 percent overall accuracy rate for the breath test.
Dr. Sheraz Markar, a research fellow at Imperial College London, said cancer cells produce a different mixture of chemicals compared to healthy cells.
"This study suggests that we may be able detect these differences," said Markar.
Benefits of A Simple Breath Test
Esophageal cancer and stomach cancer account for more than 1.4 million cancer diagnosis annually worldwide. In 2017, at least 11,000 people and 15,000 people will die from stomach and esophageal cancer respectively, according to the American Cancer Society.
Although endoscopy can diagnose both these cancers, Markar said endoscopy is far more expensive and invasive than a breath test. With that in mind, he said a simple breath test could someday be used as a first-line and non-invasive test to reduce the number of endoscopies.
Markar suggested that patients who present upper gastrointestinal symptoms could undergo an exhaled breath test as a first step.
"[T]his could also mean earlier diagnosis and treatment, and better survival," he added.
Meanwhile, Markar and his colleagues are planning to move on to a larger clinical trial to test their breath test before it could be put to practice.
They are also trying to expand the process to work on other types of cancers, such as pancreatic cancer and colorectal cancer, as a first-line test during general practice surgeries.
Details of the report were presented in Amsterdam at the European Cancer Congress 2017.