In a recent study published in the journal Oncotarget, a team of researchers from the The Wistar Institute have discovered a blood-circulating protein that is more accurate in detecting non-small cell lung cancer (NSCLC) compared to traditional screening methods. If the results from this study are validate in a larger trial, a simple blood test can be used for annual lung cancer screening.
The researchers believe that this blood test would be more accurate, easier to use, and less invasive compared to low-dose computed tomography (LDCT) scans, the U.S. Preventive Services Task Force (USPSTF) recommended method for lung cancer screening. If it proves to be highly accurate, this blood test could distinguish between benign and malignant lung tumors with the potential to grow and metastasize.
In the United States, lung cancer is the leading cause of cancer deaths in both men and women. However, and according to the American Cancer Society, if NSCLC is caught in its earliest stage, the five-year survival rate is of 49%. However, when patients are diagnosis in advanced stages of the disease the five-year survival rate is only 1%.
In 2013, the USPSTF recommended that all patients aged at least 55 years old who had a history of smoking and are at high risk for developing lung cancer should perform annual screening. However the traditional screening methods are invasive, expensive and are highly accurate or widely available on a global scale.
“There are many people who stand to benefit from a better diagnostic test for lung cancer,” said Qihong Huang, M.D., Ph.D., associate professor in the Tumor Microenvironment and Metastasis Program at The Wistar Institute and lead author of the study. “If we can develop a simple blood test that’s more accurate than low-dose CT scans, we can detect the cancer earlier with a less expensive, less invasive and more accurate blood test. Everyone stands to gain from such a test becoming available.”
The team focused on cancer testis antigens (CTAs) found in blood-circulating tumours cells. After analyzing 116 different CTAs, researchers determined that the protein AKAP4 may be used as a biomarker to distinguish between patients with and without NSCLC.
Using a pilot cohort of 264 blood samples from patients with NSCLC and 135 control samples, the researchers then examined AKAP4 as a biomarker, observing that from 264 NSCLC samples, 136 were from patients with a stage I diagnosis. This biomarker effectiveness was examined looking at the area under the curve (AUC), a procedure that is able to distinguish between patients with and without the disease. An AUC value of 1 means that the test perfectly distinguishes between the patients who have or not the disease.
“The results of this study exceeded our expectations,” Huang said. “AKAP4 appears to be a highly effective biomarker for the detection of non-small cell lung cancer. If we are able to confirm these results in a more robust study, then we have the potential for a new, more accurate screening method that could help save many, many lives.”
“Qihong and his colleagues have found a target that could result in a more accurate test than any method that’s been used to screen for non-small cell lung cancer to date,” said Dario C. Altieri, M.D., President and CEO of The Wistar Institute and director of Wistar’s Cancer Center. “With the government recommending annual screening for high-risk populations, the identification of a promising target like AKAP4 comes at a critical time. Early detection is needed in order to have a meaningful impact on this devastating disease.”
The researchers are now analyzing 600 blood samples to develop a blood test able to identify a 29-gene “signature” that can be used to distinguish patients with and without NSCLC.