New Method of Detecting Lung Cancer Relies on Gold Nanoparticles

Gold nanoparticles are at it again in the world of cancer research and development. Developed at the University of Colorado Cancer Center (CU; Aurora and Denver) and Technion University (Haifa, Israel), a cancer-detecting device uses gold nanoparticles to trap and define the molecules that make up cancer patients' exhaled breath. By comparing these molecular signatures with control groups, the device can tell not only whether a lung is cancerous but also whether the cancer is of the small- or non-small-cell type and whether it is an adenocarcinoma or a squamous cell carcinoma.

As presented in the journal Nanomedicine, a preliminary study shows that the device clearly distinguishes between the volatile organic compounds in cancer patients' exhaled breath as compared with the breath of a control group. Subjects simply exhale into a bag, which separates superficial exhaled breath from breath that originates deeper in the lungs. Then, this deep breath is analyzed by an array of gold nanoparticle sensors.

"What is unique here is that we take advantage of a nanotechnology development going on at Technion University that allows us to immediately identify very small molecules," remarks Fred R. Hirsch, investigator at the CU Cancer Center and professor of medical oncology at the University of Colorado School of Medicine. Based on the identity of these small molecules in exhaled breath, Hirsch and his colleagues can tell if the breath comes from a cancerous lung.

"We can measure the levels of volatile organic compounds against population scores to diagnose cancer and types of cancer, or can measure the change in patients' levels of VOCs across time with the intent of, for example, monitoring how well a patient responds to specific treatments," Hirsch says. A breath now and a breath after treatment could define whether a patient should stay with a drug regimen or explore other options.

The device may also help doctors improve existing methods of cancer screening. For example, the National Lung Screening Trial recently reported that one of the major challenges in its more than 53,000-person study of low-dose chest CT scans to detect lung cancer was the trial's nearly 95% false positive rate. "That calls for better measures to distinguish what's a benign nodule and a malignant nodule," Hirsch says. "That's what we in the lung cancer group here at the University of Colorado Cancer Center want to study with this technology, and we have very encouraging preliminary data. We could potentially use the exhaled breath to determine who among the individuals with a CT-detected nodule should go for further work up and/or eventually treatment."

The gold nanoparticle sensor technology could revolutionize lung cancer screening and diagnosis, Hirsch remarks. "The perspective here is the development of a nontraumatic, easy, cheap approach to early detection and differentiation of lung cancer."