Background & Aims: The percentage of Lens culinaris agglutinin-reactive (α)-fetoprotein (AFP-L3%) is proposed as a diagnostic and prognostic marker for hepatocellular carcinoma (HCC). We evaluated the utility of AFP-L3% for diagnosis of HCC in a US referral population. Methods: This retrospective study included 272 patients: 166 with HCC and 106 with benign liver disease (chronic liver disease, 77; benign liver mass, 29). The AFP-L3% was measured using a clinical auto-analyzer. Results: The AFP-L3% is not reported for a total α-fetoprotein (AFP) less than 10 ng/mL, and all patients with an AFP greater than 200 ng/mL had HCC; thus the AFP-L3% was noninformative for these patients. In patients with a total AFP of 10-200 ng/mL, an AFP-L3% greater than 10% had a sensitivity of 71% and a specificity of 63% for diagnosis of HCC. An AFP-L3% greater than 35% had a reduced sensitivity of 33%, but an increased specificity of 100%. The high specificity of the AFP-L3% cut-off of 35% allowed the confident diagnosis of an additional 10% of HCCs not diagnosed using an AFP cut-off of 200 ng/mL. After adjustment for AFP level, no association was observed between AFP-L3% and tumor size, stage, vascular invasion, grade, or survival. Conclusions: Patients with indeterminate total AFP values of 10-200 ng/mL present a diagnostic dilemma. We found that an AFP-L3% greater than 35% has 100% specificity for HCC in these patients. AFP-L3%, used in combination with AFP, may be a clinically useful adjunct marker for the diagnosis of HCC.
Bibliographical noteFunding Information:
Supported by grants from Wako Chemical USA, Mayo Clinic and Mayo Cancer Center, by National Institutes of Health grants CA82862 and CA100882, an Industry Research Scholar Award from the Foundation for Digestive Health and Nutrition, a Harold Amos Medical Faculty Development Award from The Robert Wood Johnson Foundation, a generous gift from The Richard M. Schulze Family Foundation, and by the Miles and Shirley Fiterman Center for Digestive Diseases at the Mayo Clinic, Rochester, Minnesota (L.R.R.).