Lung cancer in nonsmokers, often detected during routine computed tomography (CT) scans, may soon have an adjunctive blood test for revealing common biomarkers, according to research presented at the annual meeting of the American Association for Cancer Research.
A group of researchers from Celera Corporation in Alameda, California, evaluated more than 600 tumor samples for the study. The training set was randomly selected from smokers with non-small cell lung cancer (NSCLC) and matched controls, followed by the test set of additional NSCLC cases and matched controls.
Celera uses genotyping, gene expression analysis, and proteomics with mass spectrometry to discover biomarkers. After identifying biomarkers, researchers conducted additional studies in 80 nonsmokers, including 40 with various stages of lung cancer and 40 control subjects matched for gender and age.
Charles Birse, PhD, one of the investigators in the study and associate director of product development at Celera, reported an 83% sensitivity and specificity rate in identifying lung cancer. All stages of lung cancer and histological types were distinguished.
Bernard J. Park, MD, codivision chief, Thoracic Oncology, at the John Theurer Cancer Center said these types of tests might someday be useful. “Lung cancer is extremely hard to diagnose in an early stage,” he said. “The earlier you diagnose lung cancer, the more likely it is that you can cure patients, and that is the major challenge – to identify and diagnose patients before they have advanced disease. That is one of the major challenges that this type of serum test can definitely help.”
Park added that a more specific study of a larger proportion of patients will be needed to determine the usefulness of these biomarkers in determining the extent of the cancer. Park also stressed the importance of specifying whether these nonsmokers, who account for as many as 15% of lung cancer cases, are never smokers or former smokers.
“I think that a test like this can help when the risk profile is low, but the patient has a suspicious or indeterminate finding on a scan, then I think that using a supplemental test like that would be extremely helpful in determining whether or not there is lung cancer going on.”
“Many people undergo chest scans for heart disease prevention or other conditions and incidental nodules appear in the lungs that may or may not be benign,” Birse said. Last year, results from the National Lung Screening Trial showed that CT scans lowered the risk of dying from lung cancer by 20%, and according to Birse, with further study, this panel of biomarkers could provide an even further degree of certainty in the diagnosis.