Results from a new prospective clinical trial showed that a blood test looking at specific biomarkers was able to detect lung cancer recurrence about six months before conventional imaging methods found recurrence.

Data suggests that combining CT and PET/CT scans with blood tests could have the potential to guide personalized treatment for patients with non-small cell lung cancer (NSCLC). 

"The additional lead time afforded by an earlier diagnosis may enable doctors to better tailor alternative and salvage treatments to improve their patients' outcomes and quality of life," said Chimbu Chinniah, lead author of the study and a research fellow in radiation oncology in the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, in a statement.

The study, presented at the 2017 Multidisciplinary Thoracic Cancers Symposium, is the largest prospective clinical trial to date of circulating tumor cells (CTC) as biomarkers for locally advanced lung cancer.

The researchers enrolled 48 patients with stage II-III locally advanced NSCLC and who were treated with concurrent chemoradiation. Blood samples were received before, during, and after treatment. CTC levels were identified by analyzing the samples with an adenoviral probe that detects high activity of a specific enzyme that is produced when cancer cells replicate. CT or PET/CT scans were performed every three months.

Patients followed up approximately 10.9 months following their treatment for locally advanced NSCLC. Conventional surveillance scans and biopsies showed that 46% of the patients experienced recurrence or progression. Researchers obtained blood samples from 20 of the 22 recurrent patients following their chemoradiation therapy.

Three in four (15 of 20 patients) had elevated CTC counts following treatment. Of the 15 patients, 10 showed a rise in CTC counts an average of six months before PET/CT or CT scans detected the recurrence. While most of these elevated CTC rises were identified before imaging, four of the 20 patients experienced recurrences that were detected with imaging before elevated CTC levels showed the disease had returned.

“Although imaging remains the cornerstone of post-treatment surveillance for patients, blood tests could, and perhaps should, be used in conjunction with imaging scans to better monitor patients during their follow-up period after treatment," said Charles B. Simone, II, MD, the study's senior author and principal investigator, as well as an associate professor of radiation oncology at the University of Maryland School of Medicine and medical director of the Maryland Proton Treatment Center in Baltimore.