Lymphadenectomy in gastric cancer: Contentious issues

Table 1 Anatomical definition of lymph node stations

Lymph node station	Label	Anatomical description
1	Right paracardial	Right paracardial LNs, including those along the first branch of the ascending limb of the left gastric artery
2	Left paracardial	Left paracardial LNs including those along the esophagocardiac branch of the left subphrenic artery
3	Lesser curvature	3a: Along the branches of the left gastric artery
		3b: Along the 2nd branch and distal part of the right gastric artery
4	Left gastric curvature	4sa: Left greater curvature LNs along the short gastric arteries (perigastric area)
		4sb: Left greater curvature LNs along the left gastroepiploic artery (perigastric area)
	Right greater curvature	4d: Rt. greater curvature LNs along the 2nd branch and distal part of the right gastroepiploic artery
5	Suprapyloric	Along the 1st branch and proximal part of the right gastric artery
6	Infrapyloric	Along the first branch and proximal part of the right gastroepiploic artery down to the confluence of the right gastroepiploic vein and the anterior superior pancreatoduodenal vein
7	Left gastric aretry	Along the trunk of left gastric artery between its root and the origin of its ascending branch
8	Common hepatic artery	8a: Anterosuperior LNs along the common hepatic artery
		8p: Posterior LNs along the common hepatic artery
9	Celiac	Along the coeliac artery
10	Splenic hilum	Lymph nodes in the splenic hilum including those adjacent to the splenic artery distal to the pancreatic tail, and those on the roots of the short gastric arteries and those along the left gastroepiploic artery proximal to its 1st gastric branch
11	Splenic artery	11p: Proximal splenic artery LNs from its origin to halfway between its origin and the pancreatic tail end
		11d: Distal splenic artery LNs from halfway between its origin and the pancreatic tail end to the end of the pancreatic tail
12	Hepatoduodenal ligamant	12a: Hepatoduodenal ligament LNs along the proper hepatic artery, in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
		12b: Hepatoduodenal ligament LNs along the bile duct, in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
		12p: Hepatoduodenal ligament LNs along the portal vein in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
13	Posterior pancreatic head	On the posterior surface of the pancreatic head cranial to the duodenal papilla
14v	Superior mesenteric vein	Along the superior mesenteric vein
15	Middle colic vessels	Along the middle colic vessels
16	Para-aortic	16a1: Paraaortic lymph nodes in the diaphragmatic aortic hiatus
		16a2: Paraaortic lymph nodes between the upper margin of the origin of the celiac artery and the lower border of the left renal vein
		16b1: Paraaortic lymph nodes between the lower border of the left renal vein and the upper border of the origin of the inferior mesenteric artery
		16b2: Paraaortic lymph nodes between the upper border of the origin of the inferior mesenteric artery and the aortic bifurcation
17	Anterior surface of pancreatic head	On the anterior surface of the pancreatic head beneath the pancreatic sheath
18	Inferior border of the pancreatic body	Along the inferior border of the pancreatic body
19	Infradiaphragmatic	Infradiaphragmatic, predominantly along the subphrenic artery
20	Paraesophageal, esophageal hiatus	In the diaphragmatic esophageal hiatus
110	Paraesophageal, lower thoracic	In the lower thorax
111	Supradiaphragmatic	Supradiaphragmatic lymph nodes separate from the esophagus
112	Posterior mediastinal	Posterior mediastinal lymph nodes separate from the esophagus and the esophageal hiatus

LNs: Lymph nodes.

Table 2 Previously published randomized clinical trials addressing the extent of lymphadenectomy in gastric cancer

Ref.	Study period	Study groups	Median follow-up	Result	Conclusion
Cuschieri et al[14]	1986-1993	D1 = 200, D2 = 200	6.5 yr, overall	5-yr OS in D1 vs D2 - 35% vs 33%, (HR = 1.10, 95%CI: 0.87-1.39)	Classical Japanese D2 resection offers no survival advantage over D1 surgery
Songun et al[13]	1989-1993	D1 = 380, D2 = 331	15.2 yr, overall	5-yr OS D1 vs D2 - 21% vs 29%, (log-rank P = 0.34), subgroup analysis of patients without pancreatico-splenectomy, 15-yr OS in D1 vs D2 = 22% vs 35% (HR = 1.34, 95%CI: 1.09-1.65; log-rank P = 0.006)	Spleen preserving D2 resection should be recommended as the standard surgical approach to resectable gastric cancer
Degiuli et al[17]	1998-2006	D1 = 133, D2 = 134	6.7 yr, overall	5-yr OS in two arms D1 vs D2 - 66.5% vs 64.2%, (difference -2.3, 95%CI: -14.0 to 9.3; P = 0.695), 5-yr disease-specific survival in pathological tumour pT2-4 in two arms D1 vs D2 - 38% vs 59%; P = 0.055	No difference in overall 5-yr survival between D1 and D2 resection; D2 lymphadenectomy may be a better choice in patients with advanced disease and lymph node metastases
Wu et al[19]	1993-1999	D1 = 110, D3 = 111	94.5 mo, for survivors	5-yr OS in D1 vs D3 - 53.6% vs 59.5% difference between groups 5.9% (95%CI: -7.3 to 19.1), log-rank P = 0.041)	D3 dissection offers a survival benefit for patients with gastric cancer compared with D1 dissection
Sasako et al[21]	1995-2001	D2 = 260, D2 + PAND = 263	5.6 yr for D2 lymphadenectomy alone and 5.7 yr for D2 lymphadenectomy plus PAND 94.5 mo, for survivors	5-yr overall survival rate for D2 vs D2 + PAND -69.2% vs 70.3% HR for death 1.03 (95%CI: 0.77-1.37; P = 0.85)	No survival benefit with D2 lymphadenectomy plus PAND in curable gastric cancer as compared with D2 lymphadenectomy alone
Yonemura et al[22]	1995-2002	D2 = 135, D2 + PAND = 134	NS	5-yr overall survival rate for D2 vs D2 + PAND -52.6% vs 55.0% (χ2 = 0.064; P = 0.801)	Prophylactic D4 dissection is not recommended for patients with potentially curable advanced gastric cancer
Kulig et al[20]	1999-2003	D2 = 141, D2 + PAND = 134	Results awaited	Results awaited	Results awaited

D1: D1 lymphadenectomy; D2: D2 lymphadenectomy; OS: Overall survival; HR: Hazard ratio; PAND: Para-aortic node dissection.