Scientists in the US and China have developed the first relatively accurate lung cancer screening test based on a mucus sample. Mucus from the lungs is known as sputum, and is often used to diagnose infections. The test currently screens for 3 different microRNA (miRNA) biomarkers associated with lung cancers.
Lung cancers cause, by far, the most cancer deaths of any other type of cancer…more than colon, breast, and prostate cancers combined. Most, but not all, lung cancer patients and deaths are smokers. According to the American Cancer Society, in 2014 there were approximately 160,000 deaths from lung cancer in the U.S. alone. About 85% of lung cancers are non-small cell lung cancers (NSCLC).
As with most cancers, early detection sometimes leads to long term survival, so smokers are often regularly screened for signs of lung cancer. Today most lung cancer screening is achieved through low-dose CT scans of the chest, which, while relatively accurate and non-invasive, are also expensive. CT scans also lead to overdiagnosis by highlighting benign nodules.
The researchers evaluated the use of 13 different miRNA biomarkers associated with lung cancer and found 3 to be most reliable. In several hundred patients with known pathology, the sputum screening test was accurate in just over 80% of cases. This level of accuracy is not high enough on which to base important clinical decisions, but combined with CT scans the test may help avoid over diagnosis, or by itself could provide an early rationale for further screening. With further refining, additional miRNA biomarkers may be added to the assay to improve its accuracy.
The research appeared in the January 15 edition of the journal Clinical Cancer Research.