An analysis of clinicopathological characteristics and prognosis on hepatoid adenocarcinoma of stomach.

Abstract

e16558 Background: Hepatoid adenocarcinoma of the stomach(HAS) is a rare type of gastric adenocarcinoma(GAC). At present, histopathology is the gold standard for the diagnosis of HAS, however, HAS is easy to be missed diagnosis, and lack of a perfect diagnosis system and effective treatment strategy. In this research, clinical pathological features will be analyzed to improve the diagnostic system, judge prognosis and provide clues for exploration of pathogenesis and targeted therapy of HAS. Methods: 576 cases including 5 confirmed patients with HAS were enrolled onto this study from 1320 patients with GAC. 10 cases of HAS were diagnosed by the second histopathological examination from the other 571 enrolled cases. 30 cases from the remaining 561 enrolled patients were randomly selected as the control group. The information of the two group cases were completed by collecting the existing case data, detecting the missed immunohistochemical indicators and telephone follow-up. The clinicopathological features of the two group cases were compared, and the treatment and prognosis of 15 HAS cases were analyzed. Results: In this study, 15 cases of HAS were found in 576 patients with GAC, including 5 cases from the 1st pathological diagnosis and 10 cases from the 2nd pathological diagnosis. There was no significant difference in age, gender, HP positive rate, serum CEA or CA19-9 level, tumor size, TNM stage, tumor invasion depth, lymph node invasion, distant metastasis rate, differentiation degree, nerve/vascular invasion, and Ki-67 expression level between the two groups( P> 0.05). Compared with the control group, the serum AFP level, and the expression level of GPC3, AFP, EGFR and VEGF protein of patients in HAS group were significantly high, as well as the patients in the HAS group were more likely to develop liver metastasis( P< 0.05). The mOS was 12 mo vs 42 mo for HAS group vs control group( P< 0.05). Multivariate analysis showed immunohistochemical AFP staining intensity was an independent risk factor for prognosis of HAS. Conclusions: As a special type of GAC, HAS is prone to developing liver metastasis with poor prognosis. Based on the higher missed diagnosis rate of HAS, it is suggested to make 2nd cancer histopathological diagnosis including immunohistochemical detection of AFP and GPC3 for GAC patients with significantly increased serum AFP level. The intensity of immunohistochemical AFP staining is an independent risk factor for the prognosis of patients with HAS. VEGF, EGFR and PD-1 / PDL-1 may be potential therapeutic targets of HAS, which is worth further study.