Table 2C.

Overall NRFS for only patients with elective neck dissection

Variable	Patients	Univariate Analysis^b		Multivariate Analysis^c

		5 year NRFS, %	P	Hazard Ratio (CI)	P
LVI					0.222
No	517	86.3	0.007	Reference
Yes	87	74.7		1.43 (0.80–2.56)
Not Known^a	202
PNI					0.224
No	406	87.4	0.001	Reference
Yes	198	79.1		1.37 (0.82–2.29)
Not Known^a	202
Grade					0.572
Well	146	90.7	0.077	Reference
Intermediate	529	83.6		1.51 (0.64–3.57)
Poor	102	79.0		1.69 (0.64–4.49)
Not Known^a	29
Thickness					0.119
< 4 mm	128	89.9	0.016	Reference
≥ 4 mm	607	82.6		2.10 (0.83–5.36)
Not Known^a	71
ECS					< 0.001
pN0	558	88.6	< 0.001	Reference
pN+ECS−	148	79.2		1.62 (0.91–2.87)
pN+ECS+	72	61.1		3.99 (2.09–7.61)
Not Known^a	28
pT Stage			0.129
T1	435	87.3%
T2	204	79.3%
T3	33	83.2%
T4	99	78.2%

NRFS: neck recurrence-free survival; LVI: lymphovascular invasion; PNI: perineural invasion; ECS: extracapsular spread; pN: pathological N stage; pT: pathological T stage; CI: confidence interval.

not included in analyses

Kaplan-Meier

Cox proportional hazard