产甲胎蛋白胃癌和胃肝样腺癌

AFP-producing gastric cancer and hepatoid gastric cancer

产甲胎蛋白胃癌（AFPGC）和胃肝样腺癌（HAS）是胃癌中较为特殊的2种类型，它们之间既有联系又有区别。临床上往往将AFPGC定义为血清AFP〉20ng／ml或者免疫组化AFP阳性的胃癌，HAS的诊断主要依靠病理形态学，即具有肝细胞癌分化形态特征的原发性胃癌。AFPGC和HAS的发病率均很低，尤其是HAS，为1％左右，均易发生肝转移和淋巴结转移，预后显著差于普通胃腺癌。随着高通量测序的开展，在胃癌分子分型逐渐明确的同时，人们对AFPGC和HAS的分子背景也有了一定的认识。目前，有效治疗仍是AFPGC和HAS的最大挑战，早期诊断和根治性手术切除可以很大程度地改善患者的预后，术后密切监测血清AFP水平和腹部影像学表现，有助于及早发现肝转移，而联合肝动脉介入化疗和射频消融等局部治疗可以改善患者的预后。靶向治疗在AFPGC和HAS治疗中有着广阔的前景。

AFP-producing gastric cancer （AFPGC） and hepatoid adenocarcinoma of the stomach （HAS） are two special subtypes of gastric cancer. There are both correlation and difference between them. AFPGC is usually identified as primary gastric cancer with serum AFP level more than 20 ng/ml or showed AFP positive staining by immunohistochemistry. The diagnosis of HAS is mainly dependent on the pathological character of hepatocellular carcinoma-like differentiation of gastric cancer. The morbidity of AFPGC and HAS are rather low, especially the incidence of HAS is about 1%. The prognoses of these two subtypes are poorer than that of common gastric adenocarcinoma, clue to a high incidence rate of liver metastasis and lymph node metastasis. With the development of next-generation sequencing and other genomic technologies, gastric cancers, including these two rare subtypes, are now being investigated in more detail at the molecular level. Treatment remains the biggest challenge, early diagnosis and radical resection can dramatically improve patients＇ prognosis. Monitoring serum AFP and abdominal imaging examination during follow-up is important for early detection of liver metastasis. In combination with local treatment methods such as transarterial chemoembolization and radiofrequency ablation of liver may further extend patients＇survival time. Targeted therapy owes a great potential value in the future.