Retrospective Study of Selective Submandibular Neck Dissection versus Radical Neck Dissection for N0 or N1 Necks in Level I Patients with Oral Squamous Cell Carcinoma

Table 4

Cox’s proportional hazard model with univariate and multivariate analysis in clinically N1 necks.

	Regional control						Disease specific survival
	Univariate			Multivariate			Univariate			Multivariate
	Hazard ratio (95% CI)	P value		Hazard ratio (95% CI)	P value		Hazard ratio (95% CI)	P value		Hazard ratio (95% CI)	P value
Type of neck dissection RND/SMND	0.889 (0.289–2.412)	0.838		0.897 (0.224–2.263)	0.962		0.989 (0.346–3.086)	0.948		0.898 (0.209–2.225)	0.796
Clinical tumor stage T3, 4/T1, 2	2.857 (0.794–5.941)	0.086					3.112 (0.990–10.434)	0.040		2.465 (1.107–5.261)	0.071
Primary tumor site Tongue	1.129 (0.443–2.676)	0.877					1.024 (0.497–2.311)	0.798
Tumor depth (tongue) ≧4 mm	1.857 (0.665–3.838)	0.101					1.414 (0.736–4.109)	0.385
Poorly or moderately differentiated	2.238 (0.733–4.496)	0.163					3.212 (0.876–7.769)	0.073
Mode of invasion Grade 4	3.250 (1.805–7.727)	0.041		2.966 (0.849–7.330)	0.760		3.814 (1.018–9.012)	0.036		3.145 (1.883–7.516)	0.240
Neoadjuvant chemoradiotherapy	0.263 (0.092–0.706)	0.045		0.195 (0.087–0.451)	0.013		0.312 (0.152–0.942)	0.039		0.232 (0.090–0.596)	0.018
Pathological nodal stage pN2	3.750 (1.825–7.586)	0.031		6.869 (2.681–14.011)	0.022		5.847 (1.888–10.719)	0.005		6.989 (2.428–12.111)	0.004
Extracapsular spread	6.224 (2.484–12..234)	0.002		11.342 (5.880–20.419)	<0.001		9.868 (4.510–18.225)	<0.001		12.767 (6.926–19.446)	<0.001
Adjuvant chemoradiotherapy	1.743 (0.454–4.379)	0.473					2.637 (0.720–9.499)	0.129

SMND: selective submandibular neck dissection; RND: radical neck dissection; CI: confidence interval.