The aim of this study was to clarify the optimal abdominal lymphadenectomy for advanced in Siewert types II and III adenocarcinoma of the esophagogastric junction (AEG).
From June 2007 to June 2014, the data of 573 patients who underwent radical total gastrectomy due to advanced Siewert types II and III was collected and retrospectively analyzed. The incidence of abdominal lymph node metastasis (LNM) of each station were compared between patients with Siewert type II and III AEG. And we used the therapeutic index to assess the efficacy of abdominal lymph node dissection of each station.
Of the 573 patients, 247 (44.0%) had Siewert type II AEG and 326 (56.0%) had type III AEG. Among them, 252 patients carried out abdominal D2 lymphadenectomy and 321 patients underwent D2 lymphadenectomy without No. 10 lymphadenectomy (D2-). The mean number of dissected LNs was 34.6±13.0, and the numbers of dissected lymph nodes at each lymph node station did not significantly differ between patients with type II and III AEG (P > 0.05). The therapeutic index of No.1-3, 7, 9 and 11 LNs was over 4.0 in advanced type II AEG cases, while the index was higher than 4.0 in No.1-4 and 7-11 LNs in patients with type III AEG. The index of No.10 LNs was more than 10 in type III AEG subgroups with primary tumors invading the serosa layer (15.6), undifferentiated cancers (10.9) and tumor size ≥50mm (10.5).
Dissection of No. 1-3, 7, 9 and 11 LNs would obtain highest survival benefits regardless of the Siewert subtype. Patients with type AEG, especially those with primary tumors invading the serosa layer, undifferentiated cancers and tumor size ≥50mm might obtain relatively higher survival benefits from No. 10 lymphadenectomy.
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All authors have declared no conflicts of interest.