A non-invasive method currently being tested could one day allow doctors to detect lung cancer using just a sample of sputum coughed up at the clinic. Its low-risk nature would also enable doctors to screen people earlier, before the cancer has spread to other areas of the body and become more difficult to treat.
“The impact of screening for lung cancer with a non-invasive, low-cost test that detects the early stages could have a significant life-saving benefit,” says Alan Nelson, Ph.D., Chairman and CEO of VisionGate, Inc., the company that developed the new test.
Automated, Accurate Lung Cancer Screening
The Cell-CT platform is an automated 3D cell imaging system that uses a computer program—known as the LuCED sputum test—to identify lung cancer cells. Cancer cells have a unique biosignature—a collection of more than 800 physical characteristics, some of which are not easily identified using a standard microscope.
The saliva and mucus collected at the clinic can be mailed in to a lab for processing. Once the samples are placed in the Cell-CT machine, results are available within 10 minutes.
Preliminary testing, reported Oct. 28 at a conference of the International Association for the Study of Lung Cancer (IASLC), showed that this system could make lung cancer detection easier, cheaper, and safer.
“Results to date from this ongoing clinical study suggest that LuCED and the Cell-CT correctly identify more than nine out of every 10 cases of lung cancer with virtually no false positive results,” says Nelson, “supporting the goal of developing a new lung cancer screening paradigm that is both accurate and cost-effective.”
Current Screening Technique Limited to High-Risk Patients
The most common cause of lung cancer is current or past tobacco use. Exposure to chemicals like asbestos or radon, on the other hand, leads to a relatively small number of lung cancer cases.
According to the National Cancer Institute, lung cancer is the leading cause of cancer death in the United States, resulting in more than 150,000 deaths in 2013.
Currently, doctors screen people for lung cancer with an imaging test called a low-dose computed tomography (CT) scan. This screening test has been shown to decrease the risk of dying from lung cancer in heavy smokers, the group hardest hit by the disease.
While low-dose CT screening is effective at identifying lung cancer in heavy smokers, in NCI’s National Lung Screening Trial nearly 25 percent of the scans resulted in false-positive results. This outcome—when the test incorrectly indicates that cancer is present—can lead doctors to order unnecessary and potentially harmful lung biopsies, in which a small piece of lung tissue is removed to determine how advanced or aggressive the cancer is.
Because of the possibility of false-positive results, low-dose CT screening is only recommended for people with a high risk of lung cancer.
Early Detection Save Lives
VisionGate’s system, which can identify several types of lung cancer cells, has a very low rate of false positives. According to the company, in the 53 patients studied so far, LuCED and the Cell-CT achieved a sensitivity of more than 95 percent and specificity of 99.8 percent.
If cancer is detected, a doctor could order a follow-up lung biopsy to help determine the best course of treatment.
Before smokers start coughing up mucus in their doctor’s office, though, the company still has several hurdles to jump. The company expects to finish its current study by the end of the year, after which they will apply for approval from the U.S. Food and Drug Administration. The system may be used for a while alongside low-dose CT screening, or the company may seek FDA approval for LuCED as a stand-alone test.
An accurate and non-invasive test could allow doctors to screen more people—including lower-risk groups—for lung cancer. This could save lives, as it would allow treatment to begin earlier.
“There are 91 million Americans who are at elevated risk of lung cancer,” says Nelson. “This is VisionGate's target market for the LuCED test.”