Table 1.

Characteristics of included studies.

First author, reference, year	Country	No. of cases/event	Patient stage	Follow-up	Outcome
Cho et al. (23), 2020	Korea	878/470	I–IV	33.9 months (median)	Progression-free survival
Gonzalez et al. (22), 2020	USA	534/NA	III–IV	32 months (median)	Overall survival
Couttenier et al. (25), 2019	Belgium	6197/2918	I–IV	3.49 years (median)	All-cause morality Cancer-specific mortality
Harding et al. (24), 2019	USA	2195/796	I–IV	2.2 years (median)	Cancer-specific mortality
Baek et al. (37), 2018	Korea	866/381	NA	6.35 years (median)	Overall survival
Al-Niaimi et al. (17), 2016	USA	185/123	I–IV	91 months(median)	Progression-free survival Overall survival
Heitz et al. (16), 2016	Germany	801/682	I–IV	40 months(median)	Progression-free survival Overall survival
Watkins et al. (18), 2015	USA	1425/NA	III–IV	44.9 months (median)	Overall survival Disease-specific survival
Johannesdottir et al. (38), 2013	Denmark	6626/NA	NA	2.55 years (median)	All-cause mortality
Heitz et al. (19), 2013	Germany Belgium Canada	381/267	NA	17 months (median)	Progression-free survival Overall survival
Diaz et al. (20), 2012	USA	248/NA	III–IV	27 months(median)	Overall survival

NA, not available.