A simple test for serum free fatty acid (FFA) concentrations may be useful in diagnosing lung cancer and monitoring for recurrence of disease after surgery, according to a study presented at the Anesthesiology 2013 Annual Meeting by researchers from The Cleveland Clinic.
“This is an exciting first step to having an uncomplicated way to detect early stages of lung cancer, and perhaps other cancers,” said senior investigator Daniel I. Sessler, MD, Chair of the Outcomes Research Department at The Cleveland Clinic in Cleveland, OH. “It could also be used to measure the success of tumor resection surgery and to monitor for recurrences.”
In this study, researchers compared serum samples from 55 patients with lung cancer and 40 patients with prostate cancer to samples from 131 patients with pulmonary disease not known to have cancer. The two groups were matched for cancer propensity based on age, gender, smoking history, and family history of cancer, in addition to being matched for the presence of chronic disease that might affect free fatty acid concentrations.
Concentrations of serum FFA and their metabolites ranged from one to six times higher in patients with lung or prostate cancer than in controls.
In a second phase of the study, serum FFA concentrations were measured in 24 patients immediately before undergoing potentially curative lung cancer surgery; FFA concentrations were also measured 6 and 24 hours afterward. Results showed FFA concentrations were 3- to 10-fold lower 24 hours after surgery than they had been before.
These findings were somewhat serendipitous—the researchers first noticed changes in FFA concentrations while studying inflammatory markers in surgical patients.
According to Dr. Sessler, testing serum FFA concentrations would not be sensitive enough to be used in widespread cancer screening, but could be helpful when screening high-risk patients, especially if used in concert with other tests. For example, ambiguous results on a lung CT scan might be clarified by measuring FFA concentrations.
On the other hand, the usefulness of testing FFA concentrations in patients at high risk for prostate cancer is uncertain, according to Dr. Sessler, because a sensitive test for this cancer already exists.
A test of this kind might be most useful for monitoring for recurrence after surgery. “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.