Cancer‐associated elevation of α(1 → 3)‐l‐fucosyltransferase activity in human serum

GDP‐fucose:N‐acetylglucosaminide α(1 → 3)‐L‐fucosyltransferase activity was measured in sera of patients with various cancers using a synthetic substrate, N‐acetyl‐2′‐O‐methyllactosamine, as an acceptor. One hundred twenty‐four of the 169 patients showed significantly high levels of the enzyme activity when compared to healthy controls, irrespective of the location of their tumor. However, enzyme levels were in the normal range in patients with non‐neoplastic diseases, such as infectious disease, liver disease, and other inflammatory problems as well as in leukemic patients. The chromatofocusing profile of the enzyme using PBE‐94 gel over a pH grandient from pH 6.0 to 4.0 demonstrated that the level of the enzyme eluted at pH 5.4 was markedly elevated in the sera of stomach and ovarian cancer patients. A correlation was established between α(1 → 3)‐L‐fucosyltransferase activity and the presence of malignancy which may be used to evaluate the utility of the enzyme as a tumor marker.