Simple Blood Test May Diagnose Lung and Other Cancers
A simple blood test that measures serum free fatty acids and their metabolites may detect early-stage lung cancer and its recurrence, according to a study from The Cleveland Clinic presented at the ANESTHESIOLOGY™ 2013 Annual Meeting in San Francisco (Abstract A4267).
The study was presented at the meeting by senior investigator Daniel I. Sessler, MD, Chair of the Outcomes Research Department at The Cleveland Clinic. The first author was Jinbo Liu, MD, MS, a research fellow.
“This is an exciting first step to having an uncomplicated way to detect early stages of lung cancer, and perhaps other cancers,” said Dr. Sessler. “It could also be used to measure the success of tumor resection surgery and to monitor for recurrences.”
Dr. Sessler, an anesthesiologist, told The ASCO Post that these were “coincidental” findings stemming from a study evaluating inflammatory markers in surgical patients. “We recognized that the cancer signal was quite strong,” he said. “It was a serendipitous finding.” There are a number of mechanisms by which malignancy increases free fatty acid levels, according to Dr. Sessler.
Propensity Matched Study
The study looked at serum free fatty acids and their metabolites, hydroxyeicosatetraenoic acids and hydroxyoctadecadienes, in blood samples from 55 patients with lung cancer and 40 patients with prostate cancer. These samples were propensity-matched with samples from 131 similar pulmonary patients without known cancer, including matching for conditions known to affect free fatty acid levels.
The concentrations of the serum free fatty acids and their metabolites were up to six times greater than those measured in controls. Areas under the receiver operating characteristics curve (AUC) ranged from 0.71 to 0.82 (all P < .001) for lung cancer patients vs controls and 0.71 to 0.88 (all P < .001) for prostate cancer patients vs controls. Candidate predictors need to have an AUC > 0.50 and both sensitivity and specificity > 0.70, he said, and the findings meet that criteria.
In a second phase of the study, blood was examined preoperatively from 24 patients scheduled for lung tumor resections and again 6 and 24 hours postoperatively. Serum free fatty acid concentrations decreased by 3 to 10 times within 24 hours after tumor resection.
Dr. Sessler said the test would not be accurate enough for widespread cancer screening, but could be useful in high-risk patients, especially in conjunction with other tests. For example, spiral computed tomography (CT) screening in lung cancer saves lives, but it reveals many lung nodules that are ambiguous. “This tool could help in these equivocal cancers,” he suggested.
The utility of the test in prostate cancer, which already has a good screening assay, is less clear, he added.
The investigators believe the best use of this test could be in monitoring recurrence after resection. “The level falls close to zero after surgery, and if it spikes 8 months later or so, you would know it’s time to worry,” Dr. Sessler said.
The next step will be to conduct a prospective trial using the test as a biomarker for recurrence. The Cleveland Clinic has filed a patent application.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
