“The Siewert classification is widely used for determining which surgical procedure is used, because previous studies have shown that the pattern of lymph node (LN) metastasis depends on tumor location. In terms of surgical approaches for GEJ adenocarcinoma, a consensus was reached based on two randomized controlled trials. Siewert types I and III are treated as esophageal cancer and gastric cancer, respectively.”

“As for Siewert type I and type III cancers, another retrospective study reported that the
incidence of metastasis in LN stations other than Nos. 1, 2, 3, and 7 was extremely rare in
Siewert type I cancer, while LN stations including Nos. 4sa, 4sb, 4d, 8a, 9, and 11p showed a high incidence of metastasis in Siewert type III cancer. These results were consistent with
previous studies of GEJ cancer. Based on these results, total gastrectomy to remove the LNs along the distal portion of the stomach is considered unnecessary in Siewert type I cancer. Meanwhile, Siewert type III cancer has a high incidence of LN metastasis in No. 4d, and total gastrectomy is considered necessary.”

Hashimoto T, et al Surgical Treatment of Gastroesophageal Junction Cancer. J Gastric Cancer. 2018 Sep;18(3):209-217. doi: 10.5230/jgc.2018.18.e28. Epub 2018 Sep 7 Free Full text