Table 1.

General characteristics of the included studies.

Study	Origin	Tumour Type	Tumour Stage	Cases	Age	Study Period	TLR	Compliance to REMARK
[10]	Finland	OPSCC	I–IV	143	HPV+ 60.8 HPV− 62.2 (M)	2012–2016	TLR-5	Fulfilled all items
[12]	China	OSCC	T1–T4	90	62.5 (M)	2005–2008	TLR-3	Lacked item No. 5
[17]	Finland	NPC	I–IV	207	57 (M)	1990–2009	TLR-1, TLR-2, TLR-4, TLR-5, TLR-7, TLR-9	Fulfilled all items
[18]	Sweden	BOTSCC	I–IV	77	62 (M)	2000–2011	TLR-5, TLR-7	Lacked item No. 5
[11]	Finland	OPSCC	I–IV	331	-	2000–2009	TLR-5, TLR-7, TLR-9	Fulfilled all items
[13]	China	OSCC	I–IV	110	60 (Med)	2006–2010	TLR-4	Lacked item No. 5
[22]	China	TSCC	I–IV	60	57 (M)	2013–2015	TLR-1	Lacked items No. 1, 4, 5
[14]	China	OSCC	I–IV	166	-	2000–2011	TLR-7	Lacked item No. 3
[19]	Finland	OTSCC	1–4	197	65 (Med)	1981–2009	TLR-9	Fulfilled all items
[20]	Finland	OTSCC	I–IV	73	59 (Med)	1992–2002	TLR-2, TLR-4, TLR-5, TLR-7, TLR-9	Lacked item No. 5
[15]	China	OSCC	T1–T4	61	59.31 (M)	1992–2007	TLR-4	Lacked items No. 4,5
[16]	Germany	OSCC	I–IV	191	-	-	TLR-5	Lacked item No. 1
[21]	Finland	OTSCC	1–4	119	66 (Med)	1981–2009	TLR-5	Fulfilled all items

REMARK, Reporting Recommendations for Tumor Marker Prognostic Studies; HPV, human papillomavirus; OPSCC, oropharyngeal squamous cell carcinoma; OSCC, oral squamous cell carcinoma; NPC, nasopharyngeal carcinoma; BOTSCC, base-of-tongue squamous cell carcinoma; TSCC, tongue squamous cell carcinoma; OTSCC, oral tongue squamous cell carcinoma; M, mean age; Med, median age.