Pancreas-sparing duodenectomy with regional lymph node dissection for early-stage ampullary carcinoma: A case control study using propensity scoring methods

Table 4 Histopathological characteristics between study groups

Characteristic	PD group	PSD group	P value
	(n = 69)	(n = 69)
Tumor size (cm)	3.0 (1.5-5.0)	2.6 (0.6-4.7)	0.053
TNM classification: Primary tumor
Tis	4	3	0.071
T1	65	66	0.644
TNM classification: Regional lymph nodes, n
N0	45	49	0.339
N1	24	20	0.417
Number of positive nodes/evaluated nodes of JPS system, n (%)	22 (17.6)	18 (16.7)	0.402
JPS LN6	16/2	13/2	0.248
JPS LN8	10/0	8/0	0.375
JPS LN12	20/3	18/3	0.194
JPS LN13	39/10	34/8	0.527
JPS LN14	12/1	13/1	0.291
JPS LN17	28/6	22/4	0.396
Histopathologic types
Intestinal carcinoma	24	27	0.633
Pancreatobiliary carcinoma	42	40	0.597
Mixed type	3	2	0.304
Histologic grade
G1	32	34	0.312
G2	37	35	0.407
R0 resection, n	63	64	0.805
R1 resection, n	6	5	0.763

Data are expressed as number of patients or median (range). The Japan Pancreatic Society (JPS) system for numbering of lymph node stations: LN6, The infrapyloric node; LN8, The nodes around the anterior aspect of the common hepatic artery; LN12, The right-sided inferior nodes of the hepatoduodenal ligament; LN13, The posterior pancreatoduodenal nodes; LN14, The nodes around the superior mesenteric artery; LN17, The anterior pancreatoduodenal nodes; PD: Pancreaticoduodenectomy; PSD: Pancreas-sparing duodenectomy.