Habal N, Gupta R K, Bilchik A J, Johnson T, Morton D L
Roy E. Coats Research Laboratories, John Wayne Cancer Institute at St. John's Health Center, Santa Monica, California 90404, USA.
Ann Surg Oncol. 2000 Jun;7(5):352-6. doi: 10.1007/s10434-000-0352-y.
Although carcinoembryonic antigen (CEA) is the most frequently used marker for colon cancer, it is elevated in only 70% of patients with advanced disease and in even fewer patients with earlier stages of disease. We previously identified a 90-kDa glycoprotein, TA90, which is present in serum in the form of circulating immune complexes. TA90 is found in a variety of solid neoplasms but rarely in healthy controls (3.2%). We hypothesized that this new tumor-associated antigen may be a useful marker for colon cancer.
Serum samples from 59 patients with known colon adenocarcinoma were analyzed for the presence of CEA and TA90. Fifty-one (86%) patients had distant metastases; the remaining patients had clinically localized primary colon cancer. A murine monoclonal antibody-based enzyme-linked immunosorbent assay was used to measure concentrations of TA90-specific circulating immune complexes (TA90-IC). A positive value was defined as an optical density of more than 0.410 at 405 nm. Forty-seven (80%) of the 59 patients had serum samples for TA90 and CEA drawn at the same time.
TA90-IC concentrations were elevated more frequently than CEA concentrations (82.9% vs. 70.2%; P = .134). The combination of both markers identified more patients with colon carcinoma than did either marker alone (93.6%; P < .001).
Concomitant use of TA90-IC and CEA identified 93.6% of patients with advanced colon cancer. The role of TA90-IC in screening and monitoring progression of earlier disease deserves further investigation.
尽管癌胚抗原（CEA）是结肠癌最常用的标志物，但仅70%的晚期患者其水平升高，而早期患者中升高的比例更低。我们之前鉴定出一种90 kDa的糖蛋白TA90，它以循环免疫复合物的形式存在于血清中。TA90在多种实体瘤中被发现，但在健康对照中很少见（3.2%）。我们推测这种新的肿瘤相关抗原可能是结肠癌的一种有用标志物。
对59例已知结肠腺癌患者的血清样本进行CEA和TA90检测。51例（86%）患者有远处转移；其余患者患有临床局限性原发性结肠癌。采用基于鼠单克隆抗体的酶联免疫吸附测定法测量TA90特异性循环免疫复合物（TA90-IC）的浓度。阳性值定义为405 nm处光密度大于0.410。59例患者中有47例（80%）同时采集了TA90和CEA的血清样本。
TA90-IC浓度升高的频率高于CEA浓度（82.9%对70.2%；P = 0.134）。两种标志物联合使用比单独使用任何一种标志物能识别出更多的结肠癌患者（93.6%；P < 0.001）。
TA90-IC和CEA联合使用可识别出93.6%的晚期结肠癌患者。TA90-IC在早期疾病筛查和监测疾病进展中的作用值得进一步研究。
