Table 1.

Study characteristics

	Reference and year	Study design	No. PD	Cancer location	JPS lymph node station(s)	Lymph node resection
1	Andersen et al. (1994)18	Prospective cohort	117	PDAC + periampullary cancer	16	Unknown
2	Connor et al. (2004)19	Prospective cohort	121	PDAC + periampullary cancer	8a and 16b1	Routine
3	Cordera et al. (2007)20	Retrospective cohort	175	Pancreatic head cancer	8 and peripancreatic	On indication, reason unknown
4	Doi et al. (2007)21	Retrospective cohort	133	PDAC	6, 8, 9, 11, 12, 13, 14, 15, 16a2, 16b1, 17, 18	Routine
5	LaFemina et al. (2013)22	Retrospective cohort	147	PDAC	8a and peripancreatic	On indication, per surgeon preference
6	Massucco et al. (2009)23	Prospective cohort	77	PDAC	6, 8, 9, 12, 13, 14, 16 and 17	On indication, reason unknown
7	Nappo et al. (2015)31	Prospective cohort study	135	PDAC + periampullary cancer	16	Routine
8	Paiella et al. (2015)29	Retrospective cohort	67	PDAC	8, 12, 13, 14, 16 and 17	On indication, per surgeon preference
9	Philips et al. (2014)24	Prospective cohort	420	PDAC	8a and peripancreatic	unclear
10	Sakai et al. (2005)25	Retrospective cohort	178	PDAC	8	Routine
11	Schwarz et al. (2014)26	Prospective cohort	111	Pancreatic head cancer	16	Routine
12	Shrikhande et al. (2007)27	Retrospective cohort	29	PDAC	16	On indication, reason unknown
13	Yamada et al. (2009)28	Retrospective cohort	335	Pancreatic head cancer	16	Routine

PD, pancreatoduodenectomy; JPS, Japanese Pancreas Society; PDAC, pancreatic ductal adenocarcinoma.