目的评价血清ＣＡ＿５０对消化系肿瘤的诊断价值．方法消化系肿瘤患者１７２例，其中肝癌５４例，胃癌４３例，大肠癌５７例，胰腺癌１８例；消化系良性疾病患者８８例，其中肝硬变３６例，胃良性病变（胃炎、胃溃疡）５２例；正常对照者６０例．全部受测对象均抽空腹静脉血，分离血清，－２０℃贮存备测．采用ＲＩＡ法测定血清ＣＡ５０含量．放免药盒由中国医学科学院肿瘤研究所提供，使用国产ＦＪ６３０型γ计数仪．数据均用ｘ±ｓ表示，以正常ｘ＋２ｓ作为上限计算阳性率．结果肝癌、胃癌、胰腺癌和大肠癌血清ＣＡ５０含量分别为２４０ｋＵ／Ｌ±２１８ｋＵ／Ｌ，１２１ｋＵ／Ｌ±１０６ｋＵ／Ｌ，１８２ｋＵ／Ｌ±１０７ｋＵ／Ｌ和１６１ｋＵ／Ｌ±１１３ｋＵ／Ｌ．显著高于正常对照组及消化道良性病变组（分别为５６ｋＵ／Ｌ±４４ｋＵ／Ｌ和５６ｋＵ／Ｌ±２１ｋＵ／Ｌ，Ｐ＜００１）．消化道肿瘤有腹腔及远处转移者，其血清ＣＡ５０含量升高更为明显．结论ＣＡ５０是较好的肿瘤标记物，有助于诊断消化道肿瘤． Objective To evaluate the diagnostic value of serum CA 50 in digestive system tumors. Methods There were 172 patients with digestive tumors, including 54 liver cancers, 43 gastric cancers, 57 colorectal cancers, 18 pancreatic cancers; 88 patients with benign diseases of digestive system, including 36 cases of cirrhosis, benign gastric lesions (gasitis, gastric ulcer). 52 cases; normal controls in 60 cases. All subjects were evacuated abdominal venous blood, serum was separated, stored at -20 °C for testing. The RIA method was used to determine the serum CA 50 content. The release kit is provided by the Institute of Tumor Research, Chinese Academy of Medical Sciences, using domestically produced FJ-630 gamma counter. The data are expressed as x±s, and the positive rate is calculated using normal x+2s as the upper limit. Results The serum CA 50 content of liver cancer, gastric cancer, pancreatic cancer and colorectal cancer were 240kU/L±218kU/L,121kU/L±106kU/L,182kU/L±107kU, respectively. /L and 161kU/L±113kU/L. Significantly higher than the normal control group and the benign gastrointestinal lesions (56kU/L±44kU/L and 56kU/L±21kU/L, respectively, P<001). Gastrointestinal tumors have abdominal and distant metastases, and their serum CA 50 content is more evident. Conclusion CA 50 is a good tumor marker and is helpful for the diagnosis of digestive tract tumors.