Clinicopathologic and prognostic characteristics of alpha-fetoprotein-producing gastric cancer

Abstract

Alpha-fetoprotein-producing gastric cancer (AFPGC) accounts for 1.5%-7.1% of all gastric cancer cases. Compared with other types of gastric cancer, AFPGC is more aggressive and prone to liver and lymph node (LN) metastasis, with extremely poor prognosis. To improve understanding of AFPGC we reviewed a consecutive series of 82 AFPGC patients and investigated the prognostic factors. The incidence of AFPGC among our gastric cancer patients was 1.95%, and 29.27% of AFPGCs were diagnosed with metastasis at the time of presentation, mainly liver metastasis. The serum AFP level of patients with AFPGC was significantly associated with tumor differentiation. Histologically, these AFPGC patients were composed of 34.55% hapatiod type, 58.18% fetal gastrointestinal type, 9.09% yolk sac tumor-like type, and 14.55% mixed type. Patient gender, tumor differentiation, Lauren classification, and number of metastatic lymph nodes showed significant differences among these four subtypes. The overall survival time was 42.02 months and the 3-year cumulative survival rate was 53.13%. Age, American Joint Committee on Cancer (AJCC) TNM staging classification (TNM stage), serum AFP level, and surgery were prognostic factors for overall survival; however, TNM stage was the only independent risk factor for prognosis of AFPGC. In short, AFPGC is a rare, unique, and heterogeneous entity, and its proper identification and treatment remain a challenge. More attention should be paid to AFPGC to improve patient care and the dismal prognosis.

Keywords: alpha-fetoprotein–producing gastric cancer; overall survival; prognosis; risk factor.

Figure 1. Histologic subtypes of AFPGC

(A) hepatoid type. Large polygonal hepatocyte-like cells with clear cytoplasm, resembling metastatic hepatocellular carcinoma but without biles. (B) fetal gastrointestinal type. Neoplastic glandular like early gut origin adenocarcinoma. (C) yolk sac tumor-like type. Reticular patterns formed by a loose network of sheets or nests with flat or cuboidal cells; (D) mixed type. Pleomorphic cells formed glandular clefts. Original magnification, ×100.

Figure 2. Survival analysis for AFPGC patients

The mean overall survival (OS) of the 72 patients was 42.02 months, and the 3-year cumulative survival rate was 53.13% (A), and surgical treatment showed significant beneficial effects on OS of 72 AFPGC patients ((B), P=0.001). Compared with palliative surgery, radical surgery and curative-intent surgery produced significant survival benefits for 55 AFPGC patients with complete clinicopathologic data ((C), P=0.001). However, surgical treatment did not produce survival benefit for 21 AFPGC patients with synchronous M1 disease ((D), P=0.131), and curative-intent surgery also did not have survival advantage over palliative surgery in these M1 patients ((E), P=0.524).