Table 2.

Five‐year disease‐specific, overall, and relapse‐free survival according to locations and densities of tumor‐infiltrating CD8⁺ T cells and clinicopathological variables

Observed locations and findings	Density of tumor infiltrating CD8+ T cells and variables	DSS		OS		RFS
		Survival rate (%)	Log‐rank test (P‐value)	Survival rate (%)	Log‐rank test (P‐value)	Survival rate (%)	Log‐rank test (P‐value)
Stroma in the center of the tumor (/×400) (range 0‐200)	Cutoff point = 25 cells
	High; ≧25	92.0	P = 0.45	85.5	P = 0.34	56.5	P = 0.25
	Low; <25	88.3		80.4		65.5
Parenchyma in the center of the tumor (/×400) (range 0‐200)	Cutoff point = 9 cells
	High; ≧9	92.6	P = 0.41	85.0	P = 0.47	63.8	P = 0.74
	Low; <9	88.4		81.2		61.5
Stroma in the invading tumor edge (/×400) (range 0‐200)	Cutoff point = 64 cells
	High; ≧64	95.5	P = 0.10	90.6	P = 0.05	64.6	P = 0.66
	Low; <64	86.8		78.3		61.1
Parenchyma in the invading tumor edge (/×400) (range 0‐200)	Cutoff point = 13 cells
	High; ≧13	100.0	P < 0.01	93.6	P < 0.01	71.6	P = 0.07
	Low; <13	83.6		76.1		56.9
Periphery of the tumor (/×400) (range 0‐200)	Cutoff point = 84 cells
	High; ≧84	93.2	P = 0.32	85.9	P = 0.34	77.1	P < 0.01
	Low; <84	87.9		80.7		55.1
Clinical findings	Gender
	Male	90.7	P = 0.65	82.8	P = 0.85	65.9	P = 0.26
	Female	88.3		82.0		57.8
	Age (years)
	<67	98.2	P < 0.01	94.6	P < 0.01	73.7	P = 0.02
	≧67	83.4		73.7		54.1
	Tumor site
	Tongue/Floor of mouth	94.2	P = 0.01	88.7	P < 0.01	66.4	P = 0.10
	Others	81.3		70.7		54.5
	cT stage
	cT1	97.7	P = 0.01	95.6	P < 0.01	69.0	P = 0.10
	cT2	87.9		80.0		62.1
	cT3/4	74.5		55.6		42.9
	cN stage
	cN0	95.2	P < 0.01	87.3	P < 0.01	65.3	P = 0.14
	cN1/2	69.6		64.1		51.4
	cTNM stage
	Stage I	100.0	P = 0.01	97.1	P < 0.01	71.1	P = 0.12
	Stage II	91.5		82.9		63.6
	Stage III/IV	73.5		63.3		49.5
	Operative method
	Peroral tumor excision	96.6	P < 0.01	89.3	P < 0.01	63.3	P = 0.61
	Primary tumor excision with neck dissection	76.0		68.6		60.2
Pathological findings	Histologic grade
	Grade 1	94.5	P = 0.15	87.0	P = 0.26	70.3	P < 0.01
	Grade 2	84.5		77.0		55.1
	Grade 3	80.0		80.0		20.0
	pT stage
	pT1	98.5	P < 0.01	93.7	P < 0.01	65.8	P = 0.01
	pT2	88.3		78.4		66.1
	pT3/4	56.3		47.1		35.3
	pN stage
	pN0	96.2	P < 0.01	86.9	P < 0.01	73.8	P < 0.01
	pN1/2	62.7		62.7		14.8
	pTNM stage
	Stage I	98.2	P < 0.01	92.7	P < 0.01	74.0	P < 0.01
	Stage II	95.2		83.4		77.1
	Stage III/IV	68.6		63.7		24.7
	Lymphovascular invasion
	Absence	91.2	P = 0.22	85.2	P = 0.09	66.1	P = 0.03
	Presence	82.4		69.3		43.0
	Perineural invasion
	Absence	91.9	P < 0.01	85.4	P < 0.01	65.5	P < 0.01
	Presence	66.1		53.8		30.8
	Surgical margin status
	Negative	89.5	P = 0.73	84.0	P = 0.24	64.1	P = 0.38
	Positive	90.9		67.1		42.7

Bold indicates P < 0.05.