Background: The incidence of gastric cancers has fallen in recent decades. However, a substantial reduction in Helicobacter pylori prevalence and a substantial increase in the incidence of proximal gastric cancer (PGC) have been observed in the West and Japan, but not in other East Asian countries. The purpose of this large-volume study was to analyze prevalence, clinicopathological features, and prognosis of PGC compared with other types of gastric cancer in Korea, where there is high incidence of H. pylori infection.
Methods: Between 2000 and 2005, a total of 3,193 patients were enrolled. We analyzed clinicopathological features and survival outcomes.
Results: Chronological analysis showed increasing incidence of PGC over the study period. PGC patients were younger and had higher incidence of Bormann types III and IV than did distal gastric cancer (DGC) patients. Also, PGC was associated with a significantly higher proportion of poorly differentiated type, T3 and T4 stage, and positive lymph nodes compared with DGC. Peritoneal and other distant metastases were more common in PGC group than in DGC group. The 5-year survival rate was significantly lower in PGC than in DGC group, regardless of curative resection. Also, the N0 and N1 category significantly influenced the 5-year survival rate. Tumor-node-metastasis (TNM) stage, hepatic metastasis, and curative resection were significant prognostic factors in PGC patients.
Conclusions: PGC has increased in incidence with the respective decline in H. pylori prevalence in Korea. Survival was worse for patients with PGC than for those with DGC, regardless of curative respectability. PGC is often diagnosed at more advanced stage than other gastric cancers, and therefore early detection is critical for successful treatment.