Walking past one of the crowded outdoor eateries in New York City on a recent summer evening, I was struck by how many young women and men were smoking as they chatted away over dinner. People were packed onto the sidewalks, blowing smoke in each other’s faces (and, unfortunately, those of the passersby). I could not help but think that their breath must really stink after a long day at work, and now one cigarette after another.
Soon, it seems, your breath will reveal more than just your smoking status. If recent scientific discoveries are any indication, for smokers, your breath will be able to tell doctors whether the smoke in your lungs is actively causing cancer.
A New Twist on the Breathalyzer Test
Scientists in the United States and Israel have discovered that cancer cells (and other diseased tissues) have an altered metabolism that leaves a chemical “footprint” in the air exhaled by patients. New technology is allowing doctors to take advantage of this chemical “breath print” in order to screen for cancer and other diseases. There’s no stick, scan, or scope: All the subject needs to do is breathe into a tube!
This new twist on the breathalyzer test, also called electronic nose technology, consists of several different breath-print detector technologies, most of which use sensors based on gold or other nanomaterials. Measurements are confirmed using a lab test called gas-chromatography/mass-spectrometry (GC/MS) analysis. The detectors register breath concentrations of substances like aldehydes, hydrocarbons, alcohols, ketones, esters, nitriles, and aromatic compounds, all of which reveal information about health and disease.
The initial evidence for non-invasive breath tests came from a study published in the British Journal of Cancer, which showed that chemicals called “volatile organic compounds,” or VOCs, were elevated in the breath samples of patients with stomach cancer and ulcers. The authors concluded that the tests could open a new and promising avenue to diagnose gastric cancer and distinguish it from other diseases of the stomach, and plan to conduct a larger trial.
Additionally, two pilot studies in 2012 discovered that breath prints can not only differentiate patients with lung cancer from healthy control subjects, they can also differentiate between types of cancer caused by smoking and those that were non-smoking related. Both of these findings carry enormous treatment significance.
The Future of Breath Tests in Identifying Disease
Many types of lung disease, such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, and respiratory tract infections, have been studied using breathalyzer techniques. There is even the possibility of an “on-the-spot” tuberculosis (TB) test, which would be so much easier to administer than the current PPD test that needs to be read 48 hours after injection. At the 2014 American Society of Clinical Oncology (ASCO) annual meeting, researchers suggested that a study determining if the breathalyzer can confirm the early detection of lung cancer may be the first in the cancer arena. Lung cancer tumors produce chemicals that can easily evaporate into air and then be detected in a scent profile.
One recent study even suggests that breath prints might be helpful in detecting Alzheimer’s and Parkinson’s diseases, both of which are difficult to diagnose.
Although initial studies have demonstrated that breath prints can help distinguish patients with a particular disease from healthy control participants, and those with cancer from those with other diseases, it is not yet entirely clear that breath prints will be able to reliably differentiate one type of cancer from another.
Clinically, breath tests might prove most useful as a screening tool, used to identify patients who should undergo more definitive diagnostic imaging and clinical testing, invasive biopsy, or exploratory surgery.
Elizabeth Chabner Thompson, MD, MPH, is a radiation oncologist and founder of BFFL Co (Best Friends for Life), a maker of recovery kits, surgical and recovery bras, and other products for patients undergoing mastectomy and other surgeries or treatments for cancer and other conditions.
Articles from ：everydayhealth.com