Introduction Perineural invasion (PNI) is considered a poor prognostic factor in various malignant tumors, however, its predictive value in vulvar (VC) cancer remains unclear. This study aimed to determine the prognostic significance of PNI in patients with VC.

Methods We retrospectively analyzed clinicopathological data on 192 patients with VC treated surgically at the Salah Azaiez Institute of Tunisia between 1994 and 2022.

Results The mean age was 64.93± 13.817 years (range, 24–104 years). Surgery consisted of a radical vulvectomy, hemi vulvectomy, and pelvic exenteration in respectively 96.4%, 2.1%, and 1.6% of cases. Lymph node (LN) dissection was bilateral in 88.5% of cases. The mean tumor size was 42.21± 24.018 mm. Tumors were classified as stage FIGO I, II, III, and IV in 55.2%, 9.4%, 32.8%, and 2.6% of cases. LN metastasis was recorded in 34.9%. Perineural invasion (PNI) and lymphovascular space invasion (LVSI) were detected respectively in 13.5% (n=15) and 2.7% (n=3) of cases. The presence of PNI was associated with young age ≤50 years (46.7% vs 18.8%), advanced stage III-VI (80% vs 35.4%, p=0.001), stage LN metastasis (80% vs 35.4%, p=0.001) with a LN ratio≥0.2 (46.7% vs 12.5%, p=0.01) and bilateral groin metastasis (33.3% vs 13.5%, p=0.005), the presence of LVSI (20% vs 0%, p<0.0001, a decreased 5 years overall survival (OS) (12.8% vs 56.9%, p<0.0001) and decreased 5 years recurrence-free survival (RFS) (20.8% vs 60%, p=0.001).

Conclusion/Implications The presence of PNI in vulvar cancer is correlated to aggressive tumors and decreased OS and RFS