Impact of esophageal invasion on clinicopathological characteristics and long-term outcome of adenocarcinoma of the subcardia

Prognostic Significance of Esophagogastric Junction Invasion in Patients with Adenocarcinoma of the Cardia or Subcardia

BACKGROUND

There has been no comparison of the prognoses of Korean patients who underwent curative surgery for cancer located at the cardia or subcardia of the stomach. We performed this comparison and further investigated the prognostic significance of esophagogastric junction (EGJ) invasion in patients.

METHODS

The medical records of patients (n = 511) who were diagnosed with cardia or subcardia cancer and underwent surgery between January 2010 and May 2019 were retrospectively reviewed. Patients were further categorized into four groups for analysis: subcardia gastric cancer (sGC; subcardia cancer without EGJ invasion; n = 97), AEG (adenocarcinoma of the esophagogastric junction) type III (subcardia cancer with EGJ invasion, n = 54), AEG type II without EGJ invasion (n = 158), and AEG type II with EGJ invasion (n = 202). We compared the overall survival of the four groups using a gastric cancer staging system and evaluated the prognostic significance of EGJ invasion with multivariate analysis.

RESULTS

The median follow-up of patients was 46.0 months (range: 0-124 months). There was significant difference in overall survival curves among the four groups (p < 0.001). Subgroup analysis showed a significant difference in overall survival between the groups with and without EGJ invasion (p < 0.001). Cancers with EGJ invasion were more frequently in the cardia (p < 0.001), had a larger size (p < 0.001), and showed a more advanced pathologic stage (stages II and III; 67.6% versus 33.7%, p < 0.001) than those without EGJ invasion. EGJ invasion and the pathologic stage were significant independent prognostic factors of overall survival in cardia and subcardia cancer patients (hazard ratio 2.24, 95% confidence interval 1.32-3.81, p = 0.003).

CONCLUSION

The overall survival between patients with cardia or subcardia cancer was significantly different according to EGJ invasion. EGJ invasion was an independent prognostic factor and should be considered for staging. Additional research is needed to apply this feature to gastric and esophageal cancer classification.

Recent advances in proximal gastric carcinoma

The American Joint Committee on Cancer (AJCC) staging scheme requires staging proximal gastric carcinoma (PGC) as esophageal adenocarcinoma (EAC), which has been shown to be controversial by recent research results. To update the current research findings on PGC, we systematically reviewed and analyzed the scientific evidence on key arguments related to PGC. The data of high-quality research articles showed that PGC arised in the cardiac mucosa in the proximal stomach within 3 cm below the gastroesophageal junction. Its incidence is rising in East Asian countries, but decreasing in the West, and plateaued at a low level in the United States. PGC is a slowly progressive cancer with unknown independent risk factors and the mechanisms of pathogenesis. This carcinoma exhibits a wide histopathological spectrum and heterogeneous post-resection patient survival characteristics, and cannot be adequately staged for prognotic stratification by the current AJCC staging classification. The results on PGC genomics reveal unique genetic profiles, especially in East Asian populations. In conclusion, mounting evidence defies a simple placement of PGC in a single category of EAC for disease classification; further investigations on the mechanisms of PGC pathogenesis are urgently needed.