Table 1. Characteristics of the included studies in the meta-analysis.

First author	Year	Study country	Study type	Sample size	Median follow-up	Outcome	Stage	NOSa	Cut-off value
Beal et al [23]	2016	USA	Retrospective	525, preoperative	NRb	OS RFS	None	4	NLR ≥ 5
Chen et al [18]	2021	China	Retrospective	93, preoperative	14 months	OS	I–III	4	SII ≥ 823.99 NLR ≥ 2.225 MLR ≥ 0.325
Choi et al [24]	2019	Korea	Retrospective	178, pretreatment	8.7 months	PFS, OS	III–IV	3	MLR > 0.24 NLR > 2 PLR > 108
Cui et al [25]	2018	China	Retrospective	159, preoperative	8.06 months	OS	I–IV	4	NLR ≥ 4.39 PLR ≥ 181.85 MLR ≥ 0.30
Deng et al [19]	2019	China	Retrospective	169, preoperative	21 months	OS	I–IV	3	NLR ≥ 2.61 PLR ≥ 145.33
Li et al [26]	2021	China	Retrospective	691, preperative	53.8	OS	I–III	6	SII > 510, NLR > 2.3, PLR > 144 PC > 300
Liu et al [27]	2021	China	Retrospective	303, preoperative	NR	OS	I–IV	3	PC > 205 NLR > 2.74 PLR > 136.84
Mady et al [28]	2020	USA	Retrospective	231, metastatic	NR	OS	IV	5	NLR ≥ 5
McNamara et al [30]	2014	USA	Retrospective	304, preoperative	14.4 months	OS	I–IV	4	NLR ≥ 3.0
Murthy et al [29]	2019	USA	Retrospective	419, preoperative, given preoperative chemotherapy	39.1	OS	I–III	3	SII > 900
Pang et al [31]	2015	China	Retrospective	316, preoperative	42 months	OS	I–IV	4	PLR ≥ 117.7 PC > 300
Sun et al [32]	2020	China	Retrospective	142, preoperative	NR	OS	I–IV	4	SII ≥ 600 NLR ≥ 2.50
Tao et al [33]	2018	China	Retrospective	84, preoperative	June 30, 2017	OS	III–IV	5	NLR ≥ 3.20 PLR ≥ 117.75 MLR ≥ 0.25
Wang et al [14]	2015	China	Retrospective	223, preoperative	NR	OS	I–IV	4	PC > 178
Wu et al [34]	2014	China	Retrospective	85, preoperative	16 months	OS	I–V	5	NLR > 2.3 PC > 200
You et al [20]	2019	Korea	Retrospective	173 patients, unresectable, given gemcitabine-cisplatin	8.6 months	OS, PFS, ORR	III–IV	4	NLR > 3 PLR ≥ 190
Zhang et al [17]	2019	China	Retrospective	419, pretreatment	NR	OS	III–IV	4	SII > 440
Zhang et al [35]	2016	China	Retrospective	316, preoperative	20.97 months	OS	I–IV	4	NLR > 2.61
Zhang et al [36]	2016	China	Retrospective	98, preoperative	NR	OS	I–IV	3	NLR > 1.94 PLR > 113.34
Zhu et al [37]	2019	China	Retrospective	255, preoperative	September 2017	OS	I–IV	4	NLR ≥ 3.13 PLR ≥ 143.77 MLR ≥ 0.29

^aNOS Newcastle-Ottawa scale for cohort studies score

^bNR not reported