A team of scientists from Israel has designed a portable breath analyzer that detects lung cancer with 86% accuracy. The device could offer a rapid warning system that can detect disease before tumors are visible on X-rays.
"Our results are very promising for rapid, easy, and cost-effective lung cancer diagnostics and screenings," the researchers noted.
The sensor uses gold nanoparticles to detect levels of so-called volatile organic compounds (VOCs), which are higher in cancer patients.
Early detection of lung cancer greatly increases the chances of survival. Currently, only 15% of cases are discovered before the disease has begun to spread.
Viewing through computed tomography (CT) or chest X-rays can reduce deaths from lung cancer, but is expensive and exposes patients to unwanted radiation.
For the study, a team of researchers led by Hossam Haick of the Israel Institute of Technology took breath samples from 56 healthy people and 40 patients with lung cancer.
To avoid the pollutants, for five minutes the participants filled their lungs to the maximum several times through a filter that removed 99.99% of the organic compounds from the air, a process called "lung cleansing."
Next, the scientists looked for VOCs that, being present only in cancer patients, served as biomarkers of the disease.
They found 33 compounds that appeared in at least 83% of the group of cancer patients, and in less than 83% of the control group.
The next step was to design a chemical sensor assembly using five nanometer wide gold nanoparticles.
The average size of a human hair is about 100,000 nanometers wide.
After "training" the matrices to detect a selection of cancer-specific VOCs, Haick and his team tested it in both artificial mixtures of biomarkers and real human breath.
The researchers concluded that the devices were able to "distinguish between the breath of lung cancer patients and that of healthy patients in the control group, without the need for dehumidification or preconcentration of lung cancer biomarkers."
The researchers also suggested that the technique could be extended to other forms of cancer.
"Given the impact of the increasing incidence of cancer on healthcare budgets around the world, the proposed technology will mean significant savings for both public and private healthcare spending," they noted.