Subclassification scheme for adenocarcinomas of the esophagogastric junction and prognostic analysis based on clinicopathological features

Abstract

Background: Adenocarcinoma of the esophagogastric junction (AEG) has distinct malignant features compared with other esophageal and gastric cancers. Its management is controversial and largely influenced by tumor location and esophageal involvement. Hence, understanding the clinicopathological characteristics and prognosis of AEG is essential for optimizing treatment strategies.

Aim: To evaluate the prognosis and clinicopathological features of patients with AEG, providing insights for management strategies.

Methods: This retrospective study analyzed cases with AEG admitted between January 2016 and December 2017. Patients meeting the inclusion criteria were categorized into three groups: Type E [tumors whose center was located within 5 cm above the esophagogastric junction (EGJ)]; Type Eg (tumors whose center was situated within 2 cm below the EGJ), with a 2-cm esophageal invasion; Type Ge (tumors whose center was situated within 2 cm below the EGJ, with an esophageal invasion of < 2 cm, based on tumor location and esophageal involvement. Then, clinicopathological characteristics and survival outcomes of the groups were compared to evaluate the predictive value of the American Joint Committee on Cancer/International Alliance against Cancer 8^th edition gastric cancer and esophageal adenocarcinoma staging systems. Statistical analysis included survival analysis and Cox regression to assess prognostic factors.

Results: Totally, 153 patients with AEG were included (median follow up: 41.1 months; 22, 31, and 100 patients from type E, Eg, and Ge, respectively), with significant differences in maximum tumor length, esophageal involvement length, tumor type, pathology, differentiation, depth of invasion, and lymph node metastasis between the groups (P < 0.05). Lymph node metastasis rates at stations 1, 2, 3, and 7 were lower in type E than in Eg and Ge (P < 0.05). Survival rates for type E (45.5%) were significantly lower than those for Eg (48.4%) and Ge (73.0%) (P = 0.001). Type E tumors, vascular infiltration, T3-T4 invasion depth, and lymph node metastasis, were identified as independent prognostic factors (P < 0.05). The gastric cancer staging system outperformed the esophageal adenocarcinoma system for type Ge tumors.

Conclusion: Clinicopathological characteristics and prognoses varied between the AEG groups, with type E demonstrating distinct features. The gastric cancer staging system more accurately predicted type Ge AEG prognosis, guiding clinical decision-making.

Keywords: Adenocarcinoma of esophagogastric junction; Prognosis; Risk factors; Siewert classification; Survival rate.

Figure 1

Tumor classification. In this study, adenocarcinoma of the esophagogastric junction was classified into three categories based on the location of the tumor center and the length of esophageal infiltration, within or 2 cm below esophagogastric junction (EGJ): Type E: The tumor center was situated within 5 cm above EGJ; Type Eg: The tumor center was situated within 2 cm below EGJ, with a 2 cm esophageal invasion; Type Ge: The tumor center was situated within 2 cm below EGJ, with an esophageal invasion of less than 2 cm. EGJ: Esophagogastric junction.

Figure 2

Comparison of the survival curves of adenocarcinoma of the esophagogastric junction. A: Comparison of the survival curves of type E, Eg, and Ge adenocarcinoma of the esophagogastric junction (AEG) type E survival 45.5%, type Eg survival 48.4%, and type Ge survival 73.0%, P = 0.001; B: Comparison of the survival curves of type Siewert I and Siewert II AEG type Siewert I survival 54.5% and Siewert II survival 64.8%, P = 0.156; C: Comparison of the survival curves of type Nishi EG, E = G, and GE AEG type EG survival 57.1%, type E = G survival 60.0%, and type GE survival 75.5%, P = 0.402. AEG: Adenocarcinoma of the esophagogastric junction.

Figure 3

Comparison of survival curves for adenocarcinoma of the esophagogastric junction with different stages in the staging system of gastric cancer and esophageal adenocarcinoma. A and B: Comparison of survival curves for type E adenocarcinoma of the esophagogastric junction (AEG) with different stages in the staging system of gastric cancer and esophageal adenocarcinoma (P = 0.039 vs P = 0.011); C and D: Comparison of survival curves for type Eg AEG with different stages in gastric cancer and esophageal adenocarcinoma staging system (P = 0.000 vs P = 0.002); E and F: Comparison of survival curves of type Ge AEG with different stages in staging system of gastric cancer and esophageal adenocarcinoma (P = 0.005 vs P = 0.113). AEG: Adenocarcinoma of the esophagogastric junction.