Prognostic significance of perineural invasion in vulvar squamous cell carcinoma

Figures & data

Table 1 Clinico-pathological characteristics of patients with VSCC

Characteristic	Total	PNI	No PNI	P
n=105	n=30	n=75
Age, years	105	49.93±6.113	47.55±7.987	0.106
FIGO stage				0.211
ⅠB	38 (36.2)	7 (23.3)	31 (41.3)
Ⅱ	18 (17.1)	6 (20.0)	12 (16.0)
Ⅲ	46 (43.8)	15 (50.0)	31 (41.3)
Ⅳ	3 (2.9)	2 (6.7)	1 (1.4)
Tumour size, mm				0.027
≤40	63 (60.0)	13 (43.3)	50 (66.7)
>40	42 (40.0)	17 (56.7)	25 (33.3)
Tumour grade				0.163
G1	36 (34.3)	7 (23.3)	29 (38.7)
G2	45 (42.8)	15 (50.0)	30 (40.0)
G3	24 (22.9)	8 (26.7)	16 (21.3)
Depth of invasion, cm				<0.001
≤2	63 (60.0)	10 (33.3)	53 (70.7)
>2	42 (40.0)	20 (66.7)	22 (29.3)
Lymphovascular space invasion				0.006
No	70 (66.7)	14 (46.7)	56 (74.7)
Yes	35 (33.3)	16 (53.3)	19 (25.3)
Positive or close surgical margins				0.094
No	88 (83.8)	28 (93.3)	60 (80.0)
Yes	17 (16.2)	2 (6.7)	15 (20.0)
Adjuvant therapy (radio- or chemo-radiotherapy)				0.001
No	40 (38.1)	4 (13.3)	36 (48.0)
Yes	65 (61.9)	26 (86.7)	39 (52.0)
local/locoregional				0.002
No	72 (68.6)	14 (46.7)	58 (77.3)
Yes	33 (31.4)	16 (53.3)	17 (22.7)

Note: Values are mean ± SD or n (%). Bold values indicate P<0.05.

Abbreviations: FIGO, International Federation of Gynecology and Obstetrics; PNI, perineural invasion; VSCC, vulvar squamous cell carcinoma.

Table 2 Lymph node status of VSCC patients with or without PNI

Variable	PNI	No PNI	P
n=30	n=75
Lymph node metastasis			0.154
No	13 (43.3)	44 (58.7)
Yes	17 (56.7)	31 (41.3)
Nodal spread			0.037
Intra-nodal growth	10 (33.3)	9 (12.0)
Extra-nodal growth	7 (23.3)	22 (29.3)
Negative lymph nodes	13 (43.4)	44 (58.7)
Laterality			0.148
Unilateral positive lymph nodes	16 (53.3)	25 (33.3)
Bilateral positive lymph nodes	1 (3.3)	6 (8.0)
Negative lymph nodes	13 (43.4)	44(58.7)
Number of positive lymph nodes			0.260
0	13 (43.4)	44 (58.7)
1–2	8 (26.6)	19 (25.3)
3–5	7 (23.3)	11 (14.7)
>5	2 (6.7)	1 (13.3)

Note: Values are n (%).

Abbreviations: PNI, perineural invasion; VSCC, vulvar squamous cell carcinoma.

Table 3 Univariable and multivariable analysis to identify factors affecting disease-free survival after surgery in VSCC patients

Factor	Univariable analysis			Multivariable analysis
HR	95% Cl	P	HR	95% Cl	P
FIGO stage
ⅠB-Ⅱ	1		0.025	1		0.270
Ⅲ-Ⅳ	2.91	1.15–7.38		1.46	0.75–2.84
Tumor size, mm
≤40	1		<0.001	1		0.022
>40	4.81	2.13–10.86		3.02	1.75–7.75
Tumor grade
G1-G2	1		0.521	1		0.813
G3	1.36	0.54–3.44		0.93	0.51–1.70
Invasion depth, cm
≤2	1		<0.001	1		0.002
>2	3.45	1.85–6.44		3.11	1.50–6.44
Lymphovascular space invasion
No	1		<0.001	1		0.015
Yes	3.57	1.81–7.05		4.82	1.36–17.07
Lymph node metastases
No	1		<0.001	1
Yes	3.68	1.94–6.9		3.15	1.14–8.96	0.026
Positive or close surgical margins
No	1		<0.001	1		0.004
Yes	6.86	2.25–20.95		4.86	1.67–14.19
Perineural invasion
No	1		0.018	1		0.187
Yes	2.93	1.20–7.34		1.63	0.79–3.37

Note: Bold values indicate P<0.05.

Abbreviations: FIGO, International Federation of Gynecology and Obstetrics; VSCC, vulvar squamous cell carcinoma.

Table 4 Univariable and multivariable analysis to identify factors affecting overall survival after surgery in VSCC patients

Factor	Univariable analysis			Multivariable analysis
	HR	95%Cl	P	HR	95%Cl	P
FIGO stage
ⅠB-Ⅱ	1		0.016	1		0.111
Ⅲ-Ⅳ	3.03	1.25–8.77		1.88	0.87–4.11
Tumor size, mm
≤40	1		0.009	1		0.080
>40	3.43	1.36–8.65		1.54	0.95–2.51
Tumor grade
G1-G2	1		0.102	1		0.565
G3	2.12	0.86–5.22		0.83	0.44–1.57
Invasion depth
≤2	1		0.001	1		0.034
>2	5.39	1.91–15.18		3.13	1.09–8.96
Lymphovascular space invasion
No	1		0.006	1		0.058
Yes	3.71	1.46–9.42		3.20	0.96–10.63
Lymph node metastases
No	1		<0.001	1		0.010
Yes	3.47	1.85–6.41		2.54	1.25–5.16
Positive or close surgical margins
No	1		0.001	1		0.042
Yes	7.684	2.21–26.77		2.34	1.01–5.46
Perineural invasion
No	1		0.020	1		0.172
Yes	3.04	1.19–7.72		1.91	0.76–4.80

Note: Bold values indicate P<0.05.

Abbreviations: FIGO, International Federation of Gynecology and Obstetrics; VSCC, vulvar squamous cell carcinoma.

Figure 1 Kaplan-Meier survival curves of (A) disease-free survival (DFS) and (B) overall survival (OS) in vulvar squamous cell carcinoma (VSCC) patients with or without perineural invasion (PNI) (all patients). Significant differences were observed between the two groups.

Figure 2 Kaplan-Meier survival curves of (A) disease-free survival (DFS) and (B) overall survival (OS) in vulvar squamous cell carcinoma (VSCC) patients with or without perineural invasion (PNI) (only patients who received adjuvant therapy). No significant differences were observed between the two groups.