Elevation of ratio of urinary N-acetylneuraminlactose to free sialic acid in some advanced cancer patients

Abstract
We estimated the levels of free sialic acid and sialylated oligosaccharides excreted in the urine of normal donors (n=10) and patients with gastric cancer (n=6) and colorectal cancer (n=4). The total sialic acid level in cancer patients was similar to that in normal donors. However, the ratios of glycosidically bound sialic acids to free sialic acid were higher in some advanced cancer patients than in the normal donors. A major component of sialylated oligosaccharides was N-acetylneuraminyl α (2 → 3) lactose. The elevation of the urinary ratio of this sialylated oligosaccharide to free sialic acid observed in some advanced cancer patients in this study may reflect the elevation of sialyltransferase activity in tumor tissues.