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stage I disease is accepted for one of the options in daily clinical practice. Recently, extensive research has
been gradually performed in the field of LG for advanced gastric cancer (AGC) and demonstrated that LG
for AGC is a safe and feasible procedure with better short-term outcomes compared with open gastrectomy
(OG). However, there are few randomized clinical trials (RCT) reporting the long-term outcome of LG for
AGC previously. Moreover, it also remains controversial whether LG can be performed for AGC from the
aspect of technical and oncological issues. Clinically, we often encounter the situations that the disease is
unexpectedly diagnosed with advanced disease in laparoscopic inspection. Moreover, if it comes to that the
histological examination may reveals serosa invasions or multiple lymph node metastases even if only D1
or D1+ lymph node dissection (LND) has been done because of the clinical stage I, we are sorry D2 LND
had not been performed in such cases. So, surgeons must prepare to perform D2 LND in laparoscopic
gastrectomy and recognize the acceptable indications and limitations for AGC. Now, we summarized the
main points of surgical procedure of D2 LND and the future perspectives.

PREVIOUS STUDIES ABOUT RADICAL LG FOR AGC
Recently, many retrospective comparative studies and several prospective RCTs have reported that LG
for AGC was safe and feasible when compared to the short-term and long-term outcomes observed with
OG [2-13] . Table 1 summarizes these studies about LG for AGC in recent years. Propensity score matching
analysis (PSM) was often used for comparison the LG and OG groups in some retrospective studies [8,10,12] .
Especially, some authors demonstrated the technical safety of LDG with D2 LND for locally AGC in the
multi-institutional, prospective, phase II study [2-5,11] . Moreover, the 3- year or 5-year overall or disease-free
survival rates have been gradually reported from China, Korea, and Japan [7-13] . Majority of them reported
that LG is feasible and safe for the treatment of AGC with D2 LND compared with OG, and no significant
differences were observed in long-term over all survival (OS) and disease free survival (DFS) between
[6]
the LG group and OG group. However, Li et al. suggested higher-level tumor stage may increase the
operative risk and should be performed with caution by surgeons with considerable experience of LG. Also,
[8]
Lin et al. reported although the OS curve at each stage did not differ significantly, the survival rate
increased overall for patients with T4aN3bM0 in the OG group. Additionally, because the patient selections
in their studies are different slightly in each and there is the difference that laparoscopic total gastrectomy
(LTG) is embedded in the studies or not, we should give the result careful consideration. Collectively, it
seems that LG with D2 LND could be acceptable treatment for AGC under definite conditions by expert
surgeons.

CLINICAL INDICATIONS AND LIMITATIONS DEALING WITH LND FOR AGC
Tumor infiltration
Recently, the result of JCOG1001 (UMIN000003688) has been published, which demonstrated no survival
difference between omentectomy vs. bursectomy for T3/T4 tumors diagnoses with surgical findings in
[14]
OG . Therefore, bursectomy is not recommended as a standard procedure for AGC in Japan. However,
the significance for omentectomy only does not become clear yet, because it is determined that omentum
should be resected in both omentectomy group and bursectomy group in JCOG1001 study. Some reports
indicated that in some metastatic nodes extra-nodal expansion is recognize, which means cancer cell
spread out of lymph node capsule to adjacent adipose tissue [15,16] . Extra-nodal expansion is pointed out to
[15]
be a poor prognostic factor . Based on these reports, if the prognosis will be improved with omentectomy,
it is expected to be significant clinically for T4 tumor. Then, omentectomy is performed for patients having
tumors deeper than T3 in a lot of institutes at the moment. Presently, RCT is scheduled to launch, which
validate the non-inferiority of omentum-preserving surgery for T3/T4 tumors.

Bulky positive nodes and large primary tumor
Generally, bulky lymph node is, by definition, “one node ≥ 3 cm in diameter” or “nearby more than one
nodes ≥ 1.5 cm in diameter”, and neoadjuvant chemotherapy (NAC) is often performed in such patients.