Is Perineural Invasion an Independent Prognostic Factor for Local Recurrence in Oral Squamous Cell Carcinoma?

The purpose of this study was to analyse the independent prognostic significance of perineural invasion (PNI) on local recurrence (LR) in patients with oral squamous cell carcinoma (OSCC) managed primarily with surgery.

Clinical and histopathological data of 195 patients with OSCC were analysed retrospectively to identify risk factors associated with PNI and to evaluate its significant correlation with local recurrence, overall survival (OS) and recurrence free survival (RFS).

Patients were followed for a mean period of 39.5 ± 1.376 months and median 35 months. PNI was found in 57 patients (29.2%). PNI correlated with tongue subsite (p = 0.001), nodal metastasis (p < 0.000), depth of invasion (DOI) (p = 0.002), stage (p = 0.013) and adjuvant therapy (p < 0.001). Mean time to recurrence with PNI was significantly shorter (p = 0.002).Multivariate analysis did not establish significant relationship between PNI and LR. Kaplan–Meier curve did not show statistical significance with OS (p = 0.085) or RFS (p = 0.110).

PNI remains an aggressive factor for nodal metastasis mandating neck management for regional control. Though PNI showed no statistical significance with LR, time to recurrence in PNI positive patients were significantly shorter. Hence, close follow-up regimen becomes necessary.