Lung cancer remains the leading cause of cancer-related deaths, largely because many patients are diagnosed at a late stage. Low-dose computed tomography (CT) is the only current mode to detect lung cancer. The American Cancer Society recommends screening for at-risk individuals to improve survival, however screening rates remain low (6% according to the American Lung Association), in part due to limited access and high costs.
In a new paper published in Science Advances, researchers at the Massachusetts Institute of Technology (MIT) detail an innovative technology that could make early-stage lung cancer screenings easier and more accessible. The team developed a needle-free, imaging-free method called PATROL (point-of-care aerosolizable nanosensors with tumor-responsive oligonucleotide barcodes), which “formulates a set of DNA-barcoded, activity-based nanosensors (ABNs) into an inhalable format,” according to the paper’s abstract.
“One advantage of using inhalation is that it's noninvasive, and another advantage is that it distributes across the lung quite homogeneously,” said co-lead author of the study Edward Tan, PhD. Dr. Tan is a former MIT postdoc, and a scientist at the biotech company Prime Medicine in Cambridge, Massachusetts.
In this new screening process, an eligible patient would breathe in the nanosensors via an inhaler or nebulizer. The sensors look for targeted lung cancer proteins that, if present, produce a signal that is detected in a subsequent urine test. The other co-lead author, Qian Zhong, PhD, compared it to a pregnancy test, but slightly more complex.
According to Dr. Zhong, the time from inhalation to detection is relatively fast. He estimates that the process would take less than two hours in humans.
So far, the system has only been tested on mice that have been genetically engineered to develop human-like lung tumors. The MIT researchers used aerosol nebulizers to deliver 20 sensors, then applied a machine learning algorithm to identify the four most accurate sensors. Results of the study demonstrated a sensitivity of 84.6% among the top sensors.
Drs. Tan and Zhong, along with their team (led by Sangeeta Bhatia, MD, PhD), have begun analyzing human biopsy samples to evaluate if the sensors that worked in mice also work in humans. The lab is also researching the use of inhalable sensors to differentiate among viral, bacterial and fungal pneumonia. Dr. Tan said the technology could eventually translate to diagnosing other lung conditions, such as asthma or COPD.
