Proximal gastric cancer: lymph node metastatic patterns according to different T stages dictate surgical approach.

Background: As a common form of gastric cancer migration, lymph node metastasis largely affects the surgical treatment and prognosis of gastric cancer. Surgery is the fundamental curative option for gastric cancer that varies depending on different stages. The study aimed to compare the clinicopathological characteristics and lymph node metastatic patterns in patients of proximal gastric cancer with different T stages and investigate a reasonable radical gastrectomy approach in terms of the range of lymphadenectomy for proximal gastric cancer.

Methods: In our retrospective study, the data of 328 patients of proximal gastric cancer with different T stages were analyzed. By comparing the differences of lymph node metastatic rate and ratio, we investigated the clinicopathological characteristics and metastatic patterns of lymph nodes. Also, we were especially interested in the differences in survival rates between patients with and without No. 5 and 6 group metastasis with the same TNM stage.

Results: The overall lymph node metastatic rate and ratio of advanced proximal gastric cancer were 73.4% and 23.3%, respectively. The tumors of different T stages were statistically significant in size and differentiation degree (P < 0.05), multivariate analysis showed that the depth of tumor invasion was an independent risk factor for lymph node metastasis in proximal gastric cancer (RR, 12.025; 95% CI, 2.326 to 62.157; P = 0.003). The overall survival rate of patients with No. 5, 6 group lymph node metastasis and those without was significantly different, but the differences in survival rates between patients with and without No. 5 and 6 group metastasis with the same TNM stage were not statistically significant.

Conclusions: Different T stages in proximal gastric cancer showed different patterns and characteristics of lymph node metastasis. D2 lymphadenectomy in patients with early gastric cancer had little survival benefit because metastasis to level 2 nodes was rare. Therefore the range of the lymph node dissection in radical gastrectomy for early gastric cancer was considered reasonable. Moreover, to meet the requirements of the lymph node dissection, total gastrectomy plus D2 lymphadenectomy or more are supposed to be applied for the advanced proximal gastric cancer patients. Precise T staging largely determines the range of gastrectomy and lymphadenectomy.