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

Author	Year	Country	Cancer type	Sample size	Age	Follow-up(months)	Method	HPV infection	Cox proportional hazards model	Survival analysis	HR	NOS score	REMARK score
Dubot [18]	2018	FRANCE	HNSCC	122	56(22–78)	60	Targeted NGS	Yes	Multivariate	OS	Reported	7	15
Koole 1 [17]	2016	Netherlands	HNSCC	452	56(35–80)	68	IHC	Yes	Multivariate	OS,DFS	Reported	8	16
Monico [27]	2018	USA	LSCC	74	NR	180	ddPCR	NR	Multivariate	OS	Reported	6	12
Young [33]	2013	Australia	OTSCC	123	59(21–93)	61.2	FISH	NR	NO	OS,PFS	Reported	5	9
Koole 2 [32]	2016	Netherlands	OCSCC	512	62(24–94)	78.5	IHC	Yes	Multivariate	OS	Reported	6	16
Koole 3 [32]	2016	Netherlands	OPSCC	439	58(35–59)	57	IHC	Yes	Multivariate	OS	Reported	6	16
Mariz [28]	2019	Brazil	OTSCC	85	55.5(19–89)	NR	IHC	NR	Multivariate	OS,DFS	Reported	6	11
Starska [29]	2018	Poland	LSCC	137	61.9(45–83)	NR	Western blotting	NR	Multivariate	OS,DFS	Reported	6	12
Kim 1 [34]	2020	South Korea	LSCC	155	64(30–88)	38.8	FISH,IHC	NR	Univariate	OS,DFS	Reported	7	12
Kim 2 [34]	2020	South Korea	HPSCC	54	64(30–88)	38.8	FISH,IHC	NR	Univariate	OS,DFS	Reported	7	12
Goke [30]	2013	USA	HNSCC	555	62	NR	FISH	YES	NO	OS	Estimated	6	10

NR, not reported; NOS, Newcastle-Ottawa Quality Scale; REMARK, Recommendations for Tumor Marker Prognostic Studies; HPV, human papillomavirus; Targeted NGS, targeted next generation sequencing; IHC, immunohistochemistry; ddPCR, droplet digital PCR; FISH, fluorescence in situ hybridization.