Significance of the lymph nodes in the 7th station in rational dissection for metastasis of distal gastric cancer with different T categories

Abstract

Objective: To determine the clinicopathological characteristics, and evaluate the appropriate extent of lymph node dissection in distal gastric cancer patients with comparable T category.

Methods: A retrospective study was conducted on 570 distal gastric cancer patients, who underwent gastric resection with D2 nodal dissection, which was performed by the same surgical team from January 1997 to January 2011. We compared the differences in lymph node metastasis rates and metastatic lymph node ratios between different T categories. Additionally, we investigated the impact of lymph node metastasis in the 7(th) station on survival rate of distal gastric cancer patients with the same TNM staging.

Results: Among the 570 patients, the overall lymph node metastasis rate of advanced distal gastric cancer was 78.1%, and the metastatic lymph node ratio was 27%. The lymph node metastasis rate in the 7(th) station was similar to that of perigastric lymph nodes. There was no statistical significance in patients with the same TNM stage (stage II and III), irrespective of the metastatic status in the 7(th) station.

Conclusions: Our results suggest that to a certain extent, it is reasonable to include lymph nodes in the 7(th) station in the D1 lymph node dissection.

Keywords: Stomach neoplasms; lymph node excision; lymphatic metastasis.

Figure 1

For stage II patients, there were 48 cases with lymph node metastases. Of these, 11 patients were detected with No. 7 lymph node metastasis, while the other 37 patients had no involvement of No. 7 lymph nodes. The calculated 5-year overall survival rate of stage II patients with lymph node involvement was 68%, with No. 7 lymph node metastasis was 59%, and without No. 7 lymph node metastasis was 70%, which were not statistically significant (P=0.666).

Figure 2

A total of 226 patients were diagnosed with stage III distal gastric cancer, and lymph node metastases were found in 165 patients. Among patients with lymph node metastases, 79 cases had No. 7 lymph node metastasis, while 86 cases did not have No. 7 lymph node metastasis. The 5-year overall survival rate of patients with lymph node involvement was 34.4%, with No. 7 lymph node metastasis was 28.4%, and without No. 7 lymph node metastasis was 39.1%, which were not statistically significant according to Kaplan-Meier analysis (P=0.542).

Figure 3

A total of 77 patients were diagnosed with stage IV distal gastric cancer, and lymph node metastases were found in 40 patients. Of these, 20 patients had No. 7 lymph node involvement, while the other 20 cases did not have lymphatic invasion. The 5-year overall survival rate of patients was 7.2%, with No. 7 lymph node metastasis was 5%, and without No. 7 lymph node metastasis was 12%, which were not statistically significant (P=0.852).