Investigators demonstrated that using SELDI-TOF MS (surface enhanced laser desorption/ionization time of flight mass spectrometry) for proteomic profiling is more accurate than traditional biomarkers in distinguishing liver cancer patients from patients with hepatitis C liver cirrhosis.
The current biomarker for liver cancer in clinical use is alpha fetoprotein (AFP). “AFP not only fails to detect many early tumors but it also lacks specificity,” according to cosenior author Towia Libermann, Ph.D., director of the Genomics Center at Beth Israel Deaconess Medical Center. “Consequently, elevated AFP levels could be indicators of not only cancer but also of other liver diseases or even benign conditions, while on the other hand, many patients with small tumors will test negative for AFP.”
The researchers examined serum samples of 92 patients including 51 people with liver cirrhosis and 41 with liver cancer, which included individuals with both large and small tumors (less than 2 cm) by SELDI-TOF MS. They report being able to identify an 11-protein signature that accurately discriminated between the cirrhosis and cancer patients. The performed the study first in a training set of 26 cirrhosis and 20 liver cancer patients and then in an independent validation set of 25 cirrhosis and 19 liver cancer patients.
The resulting diagnostic value, 74% sensitivity and 88% specificity, compared favorably with the diagnostic accuracy of AFP (73% sensitivity and 71% specificity) as well as with two other biomarkers currently in clinical development for liver cancer, AFP-L3 and PIVKA-IL, according to the research group.
“Most strikingly,” notes Dr. Libermann, “in patients with small tumors, where AFP identified only three and AFP-L3 and PIVKA-II only one each, the 11-protein signature correctly identified seven of eight patients at this early stage of disease.”
The study appears in the January 15 issue of Clinical Cancer Research.