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 P0.05). 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 P0.001). 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 P0.05). 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.