BETHESDA, MD. — A test that measures six serum peptides appears to have high sensitivity and specificity in detecting hepatocellular carcinoma, Radoslav Goldman, Ph.D., reported at the annual meeting of the American Society of Preventive Oncology.
Dr. Goldman's research group at Georgetown University, Washington, analyzed serum samples from 78 patients with hepatocellular carcinoma (HCC) and 72 control patients. These patients were part of a larger case-control study of HCC that included 1,000 age- and gender-matched patients from Egypt.
The researchers compared the mass spectrometry profiles of serum from HCC and control patients. Six peptides were selected for further analysis from a set of nearly 300, said Dr. Goldman of the department of oncology at the university.
Three of the peptides occurred at significantly higher concentrations in serum from HCC patients, whereas the other three occurred at significantly higher levels in controls.
Each peptide on its own independently predicted HCC with a sensitivity and specificity comparable to the serum level of α-fetoprotein, which has been reported to detect HCC with 39%–64% sensitivity and 76%–91% specificity; α-fetoprotein testing is routinely used to detect the presence of HCC. The sensitivity and specificity of the peptides climbed to 100% and 91%, respectively, when the results for all six peptides were combined, Dr. Goldman said.
Of 45 HCC patients for whom the cancer stage was known, 11 had stage I or II and 34 had stage III or IV. “There is a nice trend for increase in the biomarkers with increasing stage of disease,” Dr. Goldman said. He is currently analyzing whether the six-peptide test can detect early-stage HCC.
The peptide test might be used in combination with a liver biopsy or imaging methods that are currently used to diagnose HCC, he suggested.
Chronic hepatitis C virus (HCV) infection accounts for about 90% of the attributable risk for HCC in Egypt. In the United States, about 50% of HCC cases have a chronic HCV etiology, according to Dr. Goldman.
Significantly more patients with HCC were positive for HCV RNA (80%) or antibodies against HCV (88%) than were control patients (22% and 33%, respectively).
Many patients in both groups had detectable antibodies against hepatitis B virus (HBV), but only a small percentage of these patients had chronic HBV infections.
The difference in the prevalence of chronic infections “is the major difference between HCV and HBV viral hepatitis,” he said. “Another important point is that for HCV, there isn't a vaccine, and there isn't one on the horizon.”