Background and aim: The Seventh American Joint Committee on Cancer (AJCC)/TNM classification defined that the classification for adenocarcinoma of the esophagogastric junction (AEG) was included in the esophageal category. However, there still remain various classifications in AEG such as the Seventh AJCC/TNM of the esophagus and the 14th Japanese Classification of Gastric Cancer staging system (JCGC) in Japan. This study was designed to evaluate the compatibility of both the Seventh AJCC/TNM of the esophagus and the 14th JCGC staging systems in Siewert type II adenocarcinoma.
Patients and methods: Between 1999 and 2011, 47 consecutive patients with Siewert type II adenocarcinoma underwent curative surgery at our Institution. We reviewed their hospital records retrospectively.
Results: Overall survival rates at 3 and 5 years were 44.3% and 33.4%, respectively. Multivariate analyses revealed that the extent of lymph node metastasis was the only independent prognostic factor (p=0.0194, HR=12.927). In the ≤pN2 group by 14th JCGC, deeper tumor depth was significantly correlated with poor prognosis, whereas in the ≥pN3 group, deeper tumor depth did not affect prognosis, suggesting a strong effect of nodal factor on prognosis and more similar prognostic stratification to the Seventh edition of the AJCC/TNM classification of the esophagus.
Conclusion: Nodal involvement status might be a more important prognostic factor than tumor depth in patients with Siewert type II adenocaricinoma. The Seventh classification of AJCC/TNM of the esophagus might be more compatible with Siewert type II adenocarcinoma.
Keywords: AJCC; Esophagogastric junctional carcinoma; JCGC; Siewert type II adenocarcinoma; TNM; staging system.