目的 探讨血清标志物CEA,CA242,CA19-9在大肠癌的表达水平和诊断价值。方法 应用酶联免疫吸附试验(ELISA)法,检测40例大肠癌和20例消化道良性疾病患者血清中的癌胚抗原(CEA)、CA242和CA19-9含量。结果 大肠癌患者血清CEA(10.85±16.20ng/ml),CA242(65.62±75.76u/ml)和CA19-9含量(39.63±69.08/ml)显著高于消化道良性病变组(P<0.01),大肠癌患者血清CEA(60.0%),CA242(52.5%)和CA19-9阳性率(40.0%)显著高于消化道良性病变组(P<0.01)。CEA,CA242,CA19-9对大肠癌有较高的阳性率,其诊断的灵敏度、特异度、阳性预测值、阴性预测值如下:CEA分别为60.0%、85.0%、88.9%、51.5%,CA242分别为52.5%、85.0%、87.5%、47.2%,CA19-9分别为40.0%、95.0%、94.1%、44.2%。CEA,CA242和CA19-9组合检测,阳性率可达85.0%,其诊断的灵敏度、特异度、阳性预测值、阴性预测值分别为85.0%、80.0%、89.5%、72.2%。血清CEA,CA242和CA19-9含量和阳性率增高程度与大肠癌Dukes分期呈正比,各期有统计学意义(P<0.05)。结论 血清CEA,CA242和CA19-9均为较好的肿瘤标志物,有助于诊断大肠癌。血清CEA,CA242和CA19-9含量和阳性率与大肠癌Dukes分期呈正比。联合检测血清标志物CEA,CA242和CA19-9可提高大肠癌诊断的阳性率。