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Page 2 of 8 Shibao et al. Mini-invasive Surg 2019;3:16 I http://dx.doi.org/10.20517/2574-1225.2019.01

INTRODUCTION
Esophageal cancer and gastric cancer are among the most common malignancies worldwide, and are a main
[1]
causes of cancer-related mortality . The term “esophagogastric junction (EGJ) tumor” refers to a tumor
that arises close to the esophagogastric junction. The incidence of EGJ cancer has dramatically increased
[2]
in the last decade . In Eastern countries, westernized lifestyle habits, Helicobacter pylori infection, obesity,
a combination of alcohol and smoking, and the increased incidence of gastroesophageal reflux disease are
thought to be possible reasons .
[3]
EGJ cancers are traditionally classified into one of the three categories of the Siewert system, which is the
most commonly used classification system, based on the location of the epicenter of the given tumor.

Type I: Adenocarcinoma of the distal esophagus with the center located within 1 to 5 cm above the anatomic
EGJ. Type II: True carcinoma of the cardia infiltrating from 1 cm on the side of the esophagus up to 2 cm
below the GEJ in the stomach. Type III: Subcardial gastric carcinoma with the tumor center between 2 and
5 cm below the GEJ.

Meanwhile, in the Japanese Classification of Gastric Carcinoma, EGJ cancer has been defined as cancer
with its center located within 2 cm of the EGJ since 1972. In 2012, the Japanese Gastric Cancer Association
and Japan Esophageal Society joint force conducted a nationwide surveillance of EGJ cancer of < 4 cm in
diameter, which included the retrospective data of 3,177 patients from 273 institutions . The joint force
[4]
presented an algorithm showing the tentative standard in the extent of lymphadenectomy, based on this
surveillance, in Japanese Gastric Cancer Treatment Guidelines, 2014 (ver. 4). Similarly, the American Joint
Committee on Cancer (AJCC) has changed the definition of EGJ cancer to a cancer whose epicenter is
within the proximal 2 cm of the cardia (Siewert I/II) in the eighth edition of the TNM classification .
[5]
However, they categorized EGJ cancer as an esophageal cancer and staged it accordingly. Meanwhile, The
National Comprehensive Cancer Network, recommends that Siewert type III tumors should be treated as
gastric cancers, since their lymph nodal flow and prognosis are different from Siewert type I and type II
cancers . Thus, a current concern of surgeons is whether Siewert type II and III cancer should be regarded-
[6]
and thus surgically approached-as the same tumor. The lack of consensus regarding the definition of EGJ
cancer and the classification scheme that could affect the standard of care for this category contribute to this
[7]
controversy .

[8]
Minimally invasive surgery have been gaining popularity in recent years. Cuschieri et al. first described the
successful performance of thoracoscopic esophagectomy for esophageal cancer in 1992, and several authors
have reported their experience with good results [9,10] . The first laparoscopy-assisted distal gastrectomy was
reported by Kitano et al. Thereafter, many clinical trials have unveiled the benefits of this technique,
[11]
generally revealing surgical and oncological outcomes that are equal to those of open surgery [12,13] . Minimally
invasive surgeries have evolved for the purpose of further reducing postoperative complications and
enhanced recovery. Intrducing minimally invasive esophagectomy (MIE) for esophageal cancer has some
potential benefits over conventional open esophagectomy (OE) . In this article, we reviewed the existing
[14]
evidence and rationale for minimally invasive surgeries of EGJ cancer.

SURGICAL APPROACH FOR THE EGJ CANCER
Although, the optimal surgical approach for these tumors remains under debate, three main surgical
approaches are applied in the resection of EGJ tumors: transthoracic esophagectomy (the right transthoracic
approach and the left transthoracic approach), transhiatal esophagectomy, and total gastrectomy. All three
approaches enable a minimally invasive approach to be pursued. Irrespective of the surgical method and
tumor stage, complete removal of the primary tumor is most relevant to prognosis .
[15]