New blood test can detect lung and prostate cancers
By Loren Grush
Published October 16, 2013
A new blood test can help detect the presence of early-stage lung and prostate cancers – as well as any recurrences of these diseases.
In a new study presented at the Anesthesiology 2013 annual meeting, researchers have found that an increased level of serum-free fatty acids and their metabolites in the blood stream can help indicate the presence of lung cancer in the body.
According to the study’s authors, such a test could be extremely beneficial for the detection and management of the disease.
“Lung cancer is the leading cause of cancer death in the U.S., and unlike some other cancers, there is no easy way to diagnose it,” senior author Dr. David Sessler, professor and chair of the department of outcomes research at the Cleveland Clinic, told FoxNews.com. “The current standard is a spiral CT, which works well, but they are expensive, and they expose patients to radiation. So having a blood test for lung cancer would be very helpful.”
Sessler said that he and his research team stumbled upon these biomarkers for lung cancer while conducting an entirely different experiment.
“It was complete serendipity,” Sessler said. “We were looking for inflammatory markers associated with a particular type of anesthesia – general anesthesia versus epidural anesthesia. There was no difference in inflammation, but we noticed that patients with lung cancer had higher incidences of these fatty acids and their metabolites.”
After making this discovery, the researchers decided to further analyze these potential biomarkers. They examined blood samples from 55 patients with lung cancer and 40 patients with prostate cancer, comparing them to samples from people without cancer. The blood samples from the cancer patients had one- to six-times greater amounts of the serum-free fatty acids and their metabolites than the samples from cancer-free patients.
In a second phase of the study, the researchers examined blood samples from 24 patients with lung cancer before they underwent curative surgery. They then analyzed the patients’ blood at six and 24 hours after surgery. The level of serum-free fatty acids and their metabolites decreased three to 10 times within 24 hours after the cancerous tumors were removed.
The researchers didn’t assess why the level of these compounds increased, but they said their findings are consistent with previous research on the relationship of serum-free fatty acids and cancer.
“The three fatty acids are necessary for cancer cell growth, and some cancers stimulate the release of these fatty acids,” Sessler said.
Though the blood test was shown to be effective in detecting the disease, the researchers argue that it should not be used as the go-to test for lung cancer screenings. However, it could be helpful for a certain population of patients.
“It’s by no means a perfect test; blood tests rarely are,” Sessler said. “It is about 75 percent for sensitivity and specificity. It is probably not a good enough test to use for routine screening, but it well could be helpful for high risk patients or patients who have found a nodule but don’t know if it’s cancerous enough.”
Sessler also said the blood test could be helpful for those who have already undergone lung cancer surgery to better understand if they will suffer recurrence.
“If someone who has lung cancer and has surgery, you might use this as a follow up,” Sessler said. “Presumably the fatty acids go down after surgery, and an increase in concentration might tell you if patient is having a relapse.”
While other blood tests do exist for some cancers – most notably the prostate-specific antigen (PSA) test for prostate cancer – Sessler said this is still an exciting discovery for the future of lung cancer treatment.
“Yes, there are some biomarkers for some cancers, but there’s no general cancer biomarker, nor has there ever been an established biomarker for lung cancer,” Sessler said.