"Electronic Nose" Detects Lung Cancer

August 21, 2009
Christina T. Loguidice

According to research presented at the 13th World Conference on Lung Cancer, volatile organic compounds found in exhaled breath may be the key to diagnosing lung and other cancers early.

According to research presented at the 13th World Conference on Lung Cancer, volatile organic compounds (VOCs) found in exhaled breath may be the key to diagnosing lung and other cancers early. An American team, led by Nir Peled, MD, PhD, Fulbright scholar at the University of Colorado Cancer Center in Denver, has been working with Hossam Haick, PhD, and his team from the Technion Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute in Haifa, Israel, to develop a bedside tool that can detect specific proteins in the parts-per billion range using sensors that are so small that thousands of them could easily fit on a single strand of human hair.

The researchers grew non-small cell lung cancer (NSCLC) lines, small-cell lung cancer lines, and pancreatic cancer cell lines, and compared them with controls. Gas-chromatography mass spectrometry was used to assess the chemical nature of the cancerous VOCs. In addition, an “electronic nose” with 18 nanotech sensors was able to detect the difference between cancerous and noncancerous cells, with each VOC yielding a different signal from the sensors.

During the study, between 350 and 400 different VOCs were identified. Of these compounds, 120 occurred in both cancerous and noncancerous cells (confidence interval, >89%), and five of them were found in all tumor cells but not in controls. Three of these five compounds were present specifically in the exhaled breath of NSCLC patients.

While the researchers hope to have a cancer breath test available within a few years, much work still needs to be done, including assessments in animal models and human validation studies in the pre- and postoperative setting. Regardless, this study has shed some light on the origin of VOCs, and based on the findings of this study, the researchers concluded that VOCs transfer to the breath of patients via a metabolic pathway present in the tumor cells. This increased understanding of the origin of these compounds “is a promising step toward an earlier, more accurate and cost-effective diagnosis for lung cancer patients,” noted Dr Peled.