Metastatic potential and prognostic significance of SOX2: A meta-analysis

Table 1 Characteristics of the included studies

Study	YOP	Patients, M/F/T	SOX2 expression, high/low	Clinical stage, I+II/ III +IV	Cancer type	Outcomes	Survival analysis	NOS
Abd El-Maqsoud et al[10]	2014	0/126/126	42/84	NA	IBC	LNM	NA	7
Chen et al[26]	2016	59/18/77	28/49	26/51	GC	DM, LNM, OS	Mu	8
Chen et al[27]	2016	233/74/307	96/211	95/212	GC	DM, LNM	NA	8
Chuang et al[14]	2015	72/3/75	40/35	21/27	ESCC	DM, LNM	NA	6
Dai et al[17]	2014	75/56/131	82/49	77/54	ACC	DM, OS, DFS	Mu	7
Ge et al[18]	2010	84/1/85	67/18	21/64	HSCC	LNM, OS, DFS	Mu	7
González-Márquez et al[19]	2014	203/17/220	74/146	24/196	SCC	DM, LNM, OS, DFS	Mu	6
Liu et al[23]	2018	35/26/61	39/22	46/15	TSCC	DM, LNM, OS	Mu	7
Liu et al[11]	2018	0/237/237	122/115	167/70	BC	LNM	NA	7
Luo et al[20]	2013	92/30/122	68/54	33/89	NPC	DM, LNM, OS	Mu	6
Neumann et al[13]	2011	58/56/114	24/90	NA	CC	DM, LNM	NA	7
Saigusa et al[15]	2011	18/2/20	8/12	10/10	ESCC	LNM, OS	U	7
Shen et al[12]	2014	0/132/132	83/49	70/62	CSCC	DM, OS	Mu	8
Sun et al[24]	2013	65/10/75	46/29	NA	HCC	DM, LNM	NA	6
Tang et al[21]	2013	152/9/161	88/73	65/96	LSCC	LNM, OS	Mu	8
Wang et al[16]	2018	87/30/117	54/63	48/69	ESCC	LNM, OS	Mu	7
Wang et al[28]	2015	132/71/203	48/155	65/138	GC	LNM	NA	6
Yang et al[25]	2013	140/82/222	124/98	173/49	SCLC	LNM	NA	7
Yoshihama et al[22]	2016	69/39/108	63/45	64/44	OSCC	DM, LNM, OS	Mu	7
Zhang et al[29]	2010	35/15/50	16/34	31/19	GC	LNM	NA	6

ACC: Adenoid cystic carcinoma of the salivary gland; CC: Colon cancer; CSCC: Cervical squamous cell carcinoma; DFS: Disease-free survival; DM: Distant metastasis; ESCC: Esophageal squamous cell carcinoma; F: Female; GC: Gastric cancer; HCC: Hepatocellular carcinoma; HSCC: Hypopharyngeal squamous cell carcinoma; IBC: Invasive breast cancer; LNM: Lymph node metastasis; LSCC: Laryngeal squamous cell carcinoma; M: Male; Mu: Multivariate; NOS: Newcastle-Ottawa scale; NPC: Nasopharyngeal carcinoma; OS: Overall survival; OSCC: Oral squamous cell carcinoma; SCLC: Small cell lung cancer; T: Total; TSCC: Tongue squamous cell carcinoma; U: Univariate; YOP: Year of publication.

Table 2 Pooled effect of the relationship between SOX2 expression (high vs low) and the clinicopathological parameters of cancer patients in the included studies

Variable	Studies	Model (I2 %)	OR (95%CI)	P-value
Age	17	F (0)	1.07 (0.90-1.28)	0.43
Sex	16	F (0)	1.13 (0.90-1.41)	0.29
Clinical stage	18	R (79)	1.51 (0.97-2.37)	0.07
Tumor size	9	F (27)	1.06 (0.84-1.33)	0.64
Tumor differentiation	14	R (54)	1.19 (0.80-1.75)	0.39

CI: Confidence interval; F: Fixed effects model; OR: Odds ratio; R: Random effects model.

Table 3 Subgroup analysis of the association between SOX2 expression (high vs low) and LMN and DM

Variable		LNM								DM
		Studies		Model (I2%)		OR (95%CI)		P-value		Studies		Model (I2%)		OR (95%CI)		P-value
Sample size
< 150	13		R (83)		1.85 (0.96-3.56)		0.06		12		F (47)		2.16 (1.61-2.91)		< 0.0001
≥ 150	5		R (85)		0.93 (0.43-2.01)		0.11		1		N/A		0.24 (0.05-1.15)		0.007
Cancer type
Head and neck	6		R (88)		1.89 (0.72-4.96)		0.19		7		F (39)		2.46 (1.63-3.72)		< 0.0001
Esophagus	3		R (79)		0.98 (0.24-4.04)		0.98		1		N/A		0.56 (0.09-3.57)		0.54
Cervix	-		-		-		-		1		N/A		3.12 (0.99-9.82)		0.05
Stomach	4		R (85)		0.68 (0.21-2.24)		0.53		2		R (56)		0.56 (0.16-1.96)		0.36
Breast	2		F (0)		2.87 (1.50-5.50)		0.002		-		-		-		-
Liver	1		N/A		1.68 (0.39-7.32)		0.49		1		N/A		4.80 (1.56-14.76)		0.006
Lung	1		N/A		1.74 (1.02-2.89)		0.04		-		-		-		-
Colon	1		N/A		4.15 (1.43-12.09)		0.009		1		N/A		3.04 (1.15-8.04)		0.03
Quality score
≥ 7	12		R (88)		1.64 (0.82-3.27)		0.16		7		R (69)		2.23 (1.04-4.77)		0.04
< 7	6		R (79)		1.38 (0.60-3.18)		0.45		6		F (35)		1.71 (0.89-3.27)		0.11

DM: Distant metastasis; F: Fixed effects model; LNM: Lymph node metastasis; OR: Odds ratio; R: Random effects model.