Table 2.

Subgroup analysis of the studies reporting the prognostic value of SOX2 expression

Outcome	Subgroups	Cohorts	HR (95% CI)	P	Model	Heterogeneity
						I2	P
OS	All	9	1.54 (1.09-2.18)	0.01	Random	44%	0.07
	Cancer type
	LC	2	1.79 (1.05-3.14)	0.03	Fixed	0	0.67
	HPC	2	0.87 (0.58-1.31)	0.5	Fixed	0	0.95
	NPC	2	1.38 (0.79-2.24)	0.26	Fixed	36%	0.21
	Histological type
	SCC	8	1.33 (1.03-1.74)	0.03	Fixed	40%	0.11
	ACC	1	2.64 (1.20-5.78)	0.02	Fixed	N/A	N/A
	Region
	Asia	6	1.64 (1.08-2.50)	0.02	Random	47%	0.09
	Europe	3	1.18 (0.75-1.87)	0.48	Fixed	48%	0.15
	Median follow-up time
	≥ 36 month	7	1.54 (1.16-2.05)	0.003	Fixed	37%	0.15
	< 36 month	2	1.49 (0.44-5.01)	0.52	Random	73%	0.06
	Sample size (n)
	≥ 100	5	1.45 (1.07-1.97)	0.02	Fixed	47%	0.11
	< 100	4	1.67 (0.84-3.31)	0.14	Random	55%	0.08

Abbreviations: HR, hazard radio; CI, confidence internal; OS, overall survival; SCC, squamous cell carcinoma; ACC, adenoid cystic carcinomas; LC, laryngeal carcinoma; HPC, hypopharyngeal carcinoma; NPC, nasopharyngeal carcinoma.