Biomarker Testing Detects Lung Cancer Recurrence 6 Months Prior to CT Imaging

According to a new clinical trial, circulating tumor cells (CTCs) can serve as a biomarker that alerts clinicians to the recurrence of non-small cell lung cancer (NSCLC) months before it is detected by a computerized tomography (CT) scan.

The research, which was presented at the 2017 Multidisciplinary Thoracic Cancers Symposium, focused on patients with locally advanced NSCLC undergoing chemotherapy, according to a press release from the American Society for Radiation Oncology. During the 2-year study period, 48 participants gave blood samples before, during, and after treatment, and received CT or positron emmision tomography/CT scans every 3 months.

CTCs are cancer cells that enter the blood stream, so elevated levels could signal to clinicians that localized disease has reappeared. Since the testing can be done on a simple blood draw, it represents an easier and quicker way to monitor cancer recurrence that can be performed more frequently than the traditional surveillance method of CT scans, which are usually performed at longer intervals.

Cancer recurrence was detected by conventional scans in 22 patients. Of the 20 who had blood samples drawn after undergoing chemoradiation therapy, 15 had elevated CTC counts. Two-thirds of this group showed an increase in CTC levels an average of 6 months before the recurrence was detected by the scans.

However, the researchers noted that in 4 of the 20 patients, recurrence was first detected by imaging, rather than the CTC blood counts. Still, they suggested that the blood tests could be added to supplement the use of scans after treatment, rather than replacing them.

Other biomarkers, such as circulating tumor DNA, have been explored as a tool for detecting lung cancer recurrence, but trials of their efficacy have only been performed in patients with metastatic disease, who are unlikely to benefit from additional therapy. Using CTC counts to detect localized cancer recurrence, however, could give clinicians a head start in administering the most effective treatments, compared with traditional scans.

“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 lead study author Chimbi Chinniah, research fellow in radiation oncology in the Perelman School of Medicine at the University of Pennsylvania, in the press release. “Earlier detection of recurrence may even translate into an increased likelihood of curing these patients when their tumor burden is lowest and thus more likely to respond to therapy.”