关键词: 胃肿瘤, 甲胎蛋白, 临床病理学特征, 预后

Abstract: Background and purpose: Serum alpha-fetoprotein (AFP) positive gastric cancer is a clinically rare gastric malignant tumor with significantly different biological characteristics from ordinary gastric cancer. This study explored clinicopathological characteristics of gastric cancer patients with elevated AFP and risk factors affecting prognosis. Methods: A cohort study was used to retrospectively analyze 2 386 gastric cancer patients who underwent radical surgery from Jan. 1, 2012 to Jan. 1, 2015 in the Third Department of the Fourth Hospital of Hebei Medical University, and patients with preoperative elevated serum AFP were selected to analyze clinical characteristics and factors affecting prognosis. Results: Among the 2 386 gastric cancer patients, 245 had positive preoperative serum AFP (AFP≥20 ng/mL, 10.27%), and the remaining 2 141 patients had normal preoperative serum AFP (AFP< 20 ng/mL, 89.73%). Compared with negative serum AFP group, patients in positive serum AFP group had higher rates of simultaneous liver metastasis, metachronous liver metastasis, lymph node metastasis and vascular invasion (all P<0.05). Complete follow-up data were obtained from 2 273 (95.26%) gastric cancer patients. The 5-year overall survival (OS) of the group was 49.32%, and the 5-year disease-free survival (DFS) was 44.61%. Among patients with positive serum AFP, the 5-year OS was 37.50% and the 5-year DFS was 34.17%, while the 5-year OS and DFS of patients with negative serum AFP were 50.90% and 45.84%, respectively. The differences in 5-year OS and DFS between the two groups were statistically significant (all P<0.001). Univariate analysis showed that the preoperative serum AFP expression level, age, lesion site, tumor diameter, histological type, Borrmann classification, tumor invasion depth pT stage, lymph node metastasis pN stage, tumor pTNM stage, Lauren type, presence or absence of vascular tumor thrombus, the proportion of positive Ki67, postoperative chemotherapy and postoperative liver metastasis were risk factors affecting the prognosis of patients with serum AFP positive gastric cancer (all P<0.05). Multivariate analysis found that the level of serum AFP (P=0.001), tumor histology type (P=0.002), tumor infiltration depth pT stage (P=0.006), lymph node metastasis pN stage (P=0.014), tumor pTNM stage (P=0.001), presence or absence of vascular tumor thrombus (P=0.024) and postoperative liver metastasis (P=0.008) were independent risk factors affecting prognosis, and postoperative adjuvant chemotherapy (P=0.031) was a protective factor. Conclusion: AFP positive gastric cancer is prone to liver and lymph node metastases with poor prognosis. The level of serum AFP is an independent risk factor affecting prognosis of the patients. As the level of AFP increases, the prognosis becomes worse.

Key words: Gastric tumor, Alpha-fetoprotein, Clinicopathological features, Prognosis