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; Siewert classification; Survival rate; Prognosis; Risk factors

Core Tip: This study introduces a novel subclassification for adenocarcinoma of the esophagogastric junction (AEG) based on the tumor center location and esophageal invasion. By distinguishing between types E, Eg, and Ge AEGs, the study identified significant differences in clinicopathological features and prognoses. Type E tumors were associated with poorer outcomes, and the American Joint Committee on Cancer/International Alliance against Cancer gastric cancer staging system more accurately predicted the prognosis of type Ge AEGs than did the esophageal adenocarcinoma system. This subclassification therefore improves prognosis prediction and may guide tailored clinical management for patients with AEG.