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 2

Characteristics of patients who underwent neck dissection (clinically N0 neck/clinically N1 neck).

Type of neck dissection	Clinically N0 neck (110)			Clinically N1 neck (68)
	SMND (77)	MRND (33)	P value	SMND (32)	RND (36)	P value
Primary tumor site						0.825
Tongue	28 (36.4%)	13 (39.4%)	0.923	14 (43.8%)	13 (36.1%)
Lower gum	31 (40.3%)	13 (39.4%)		11 (34.4%)	14 (38.9%)
Upper gum	7 (9.1%)	3 (9.1%)		3 (9.4%)	4 (11.1%)
Buccal mucosa	6 (7.8%)	3 (9.1%)		1 (3.1%)	3 (8.3%)
Oral floor	2 (2.6%)	1 (3.0%)		3 (9.4%)	2 (5.6%)
Others	3 (3.9%)	0 (0.0%)		0 (0.0%)	0 (0.0%)
Clinical tumor stage
cT1/2	55 (71.4%)	23 (69.7%)	0.513	10 (31.3%)	9 (25.0%)	0.381
cT3/4	22 (28.6%)	10 (30.3%)		22 (68.7%)	27 (75.0%)
Tumor differentiation
Poorly differentiated	5 (6.5%)	2 (6.1%)	0.982	2 (6.3%)	2 (5.6%)	0.991
Moderately differentiated	22 (28.6%)	10 (30.3%)		9 (28.1%)	10 (27.8%)
Well differentiated	50 (64.9%)	21 (63.6%)		21 (65.6%)	24 (66.7%)
Mode of invasion
Grade 1–3	58 (75.3%)	23 (69.7%)	0.348	22 (68.8%)	23 (63.9%)	0.435
Grade 4	19 (24.7%)	10 (30.3%)		10 (31.2%)	13 (36.1%)
Neoadjuvant chemoradiotherapy	26 (33.8%)	12 (36.4%)	0.479	19 (59.4%)	19 (52.8%)	0.325
Pathological nodal stage			0.603
pN0	72 (93.5%)	29 (87.9%)		5 (15.6%)	6 (16.7%)	0.828
pN1	4 (5.2%)	3 (9.1%)		24 (75.0%)	25 (69.4%)
pN2b	1 (1.3%)	1 (3.0%)		3 (9.4%)	5 (13.9%)
Extracapsular spread	1 (1.3%)	2 (6.1%)	0.214	3 (9.4%)	4 (11.1%)	0.567
Adjuvant chemoradiotherapy	5 (6.5%)	4 (12.1%)	0.264	2 (6.3%)	4 (11.1%)	0.395

SMND: selective submandibular neck dissection; RND: radical neck dissection; MRND: modified radical neck dissection.