Abstract:

Background and purpose: It is not clear that the pattern of lymph node (group 12a) metastasis within the hepatoduodenal ligament (along the hepatic artery) in gastric cancer, its indications for dissection are still controversial, and there is a lack of relevant clinical study data from large samples. This study investigated the risk factors of lymph node group 12a metastasis in gastric cancer at different sites by observing the lymph node metastasis rate. Methods: The medical records of 1 112 gastric cancer patients admitted to the Department of Gastric Surgery in Henan Provincial People’s Hospital from May 2016 to July 2021 were retrospectively analyzed. According to tumor location, they were divided into upper gastric cancer (561 cases), gastric body cancer (224 cases) and gastric antrum cancer (327 cases). The lymph node metastasis rate of group 12a in patients with different parts of gastric cancer was recorded. The c2 test and Fisher’s exact probability test were used to compare the relationship between group 12a lymph node metastasis and clinicopathological features in patients with gastric cancer at different sites. Multivariate logistic regression analysis was used to analyze the risk factors of group 12a lymph node metastasis in patients with gastric cancer at different locations. Results: Group 12a lymph node metastasis occurred in 72 of 1 112 gastric cancer patients, and the overall metastatic rate was 6.5%. Among the 561 cases of upper gastric cancer, 25 cases developed group 12a lymph node metastasis, and the metastatic rate was 4.5%. Of the 224 patients with gastric body cancer, 17 cases were positive in group 12a lymph nodes, and the metastasis rate was 7.6%. Among the 327 cases of gastric antrum cancer, 30 cases were positive in group 12a lymph nodes, and the metastatic rate was 9.2%. Taking the lymph node metastasis in group 12a as the dependent variable, and taking the indicators with statistical significance in univariate analysis as independent variables, they were included in the model for multivariate logistic regression analysis. The results showed that tumor diameter (OR=3.122, 95% CI: 2.896-3.366, P<0.001), T stage (OR=2.406, 95% CI: 1.705-3.396, P<0.001), TNM stage (OR=7.910, 95% CI: 4.755-13.160, P<0.001) were risk factors for lymph node metastasis in group 12a of upper gastric cancer patients. Tumor diameter (OR=2.757, 95% CI: 2.495-3.047, P<0.001), T stage (OR=3.298, 95% CI: 2.346-4.638, P<0.001), vascular nerve invasion (OR=1.839, 95% CI: 1.368-2.473, P<0.001) were risk factors for lymph node metastasis in group 12a of patients with gastric body cancer. Body mass index (BMI) (OR=1.098, 95% CI: 1.023-1.178, P=0.010), tumor diameter (OR=2.865, 95% CI: 1.778-4.616, P<0.001), T stage (OR=13.497, 95% CI: 8.363-21.783, P<0.001), TNM stage (OR=3.806, 95% CI: 3.113-4.653, P<0.001) were risk factors for lymph node metastasis in group 12a of patients with gastric antrum cancer. Conclusion: The total lymph node metastasis rate in group 12a is low. Tumor size, invasion depth, N stage and tumor stage are independent risk factors for group 12a lymph node metastasis in gastric cancer. Besides, vascular nerve invasion is the independent risk factors for gastric body cancer. Gastric body cancer and gastric antrum cancer require routine dissection of group 12a lymph nodes. The metastatic rate of lymph nodes in group 12a of upper gastric cancer is low, and routine dissection is not required. However, when the diameter is ≥6 cm, the depth of tumor invasion is deep (T₃-T₄), and the tumor stage is late (Ⅲ-Ⅳ), group 12a lymph nodes need to be dissected.

Key words: Gastric cancer, Lymph node metastasis rate, Group 12a lymph nodes