The fucosylation index of alpha-fetoprotein and its usefulness in the early diagnosis of hepatocellular carcinoma.

The serum concentration and degree of fucosylation (fucosylation index) of alpha-fetoprotein (AFP) were determined in serum samples from 258 patients with hepatocellular carcinoma (HCC) and 114 patients with benign liver diseases. When the serum AFP concentration was below 1000 ng/ml, it could not be used as a measure to distinguish between HCC and benign liver diseases. However, the fucosylation index of AFP proved useful for such a purpose. The sensitivity of the analysis using the fucosylation index in total patients with HCC was 69%; the specificity was 96% in benign liver diseases, and the accuracy of this test was 77%. When HCC patients who were grouped according to tumor size (5 cm, 3 cm, and 2 cm in diameter) were analyzed, they all had a fucosylation index significantly higher than that in benign liver disease patients. The mean fucosylation index in 28 patients with a serum AFP concentration below 1000 ng/ml and a tumor diameter less than 3 cm was 26 +/- 30%. Corresponding values for 16 patients with an AFP concentration below 400 ng/ml and a tumor size less than 3 cm and for 8 patients with a concentration below 400 ng/ml and a tumor size less than 2 cm were 32 +/- 31% and 27 +/- 27%, respectively. These values were higher, with statistical significance, than those in patients with benign liver diseases. These data indicate that the measurement of the fucosylation index of AFP is useful for the early diagnosis of HCC.