ＣＡ19- 9是一种胃肠道的肿瘤相关抗原 ,由糖链乳酸 -Ｎ -岩藻戊糖唾液酸联结构成 ,分子量为 30 0万至 5 0 0万道尔顿[1] 。临床研究显示ＣＡ19- 9与胰腺癌的关系最为密切 ,与胆囊癌、胆管癌、胃癌、结直肠癌也有一定的相关性[2 ] 。进一步研究发现 ,ＣＡ19- 9含量的高低对上述 CA19-9 is a gastrointestinal tumor-associated antigen composed of glycosyl lactate-N-fucopentanose sialic acid with a molecular weight of 300,000 to 500,000 Daltons [1]. Clinical studies have shown that CA19-9 has the closest relationship with pancreatic cancer, and has a certain correlation with gallbladder cancer, cholangiocarcinoma, gastric cancer, and colorectal cancer [2]. Further research found that the level of CA19-9 is higher than the above