Detecting Upper-Gut Cancer From a Simple Breath Sample

Cancers of the esophagus and stomach are often caught late, partly because early testing usually requires an invasive endoscopy. This 2018 study explored a far gentler possibility: could a breath sample reveal these cancers?

What the researchers did

The team collected exhaled breath from 335 people across three London hospitals — 163 with confirmed esophageal or gastric cancer and 172 without. Each sample was analyzed with a sensitive laboratory technique called selected ion flow tube mass spectrometry, which identifies and measures the volatile organic compounds present in breath. The researchers built a model from a panel of these compounds and tested how well it could separate cancer cases from controls.

What they found

• The breath test identified cancer with roughly 80% sensitivity and 81% specificity.
• Its overall accuracy, measured as the area under the ROC curve, was 0.85 — a strong result for a non-invasive screening approach.
• The signal came from a distinctive mix of volatile compounds associated with the cancer.

“The breath test correctly identified cancer in 81 of every 100 samples tested, supporting its potential as a noninvasive diagnostic tool.”

This research reinforces a powerful idea: the volatile chemicals our bodies release carry real information about health. It is shared here as interesting published science for general education, and is not a diagnostic tool or medical advice.