Perineural invasion in oral squamous cell carcinoma: Quantitative subcategorisation of perineural invasion and prognostication

Abstract

Multifocal PNI is associated with poor outcomes even with PORT suggesting consideration of therapeutic escalation, particularly with involved nerves ≥1 mm. Unifocal PNI did not affect prognosis even in the absence of PORT, which may not be required if this is the sole risk factor. Prospective validation and testing of these hypotheses is essential before implementation.

Adjuvant radiotherapy for early head and neck squamous cell carcinoma with perineural invasion: A systematic review

“…When tumor involved large nerves, it predicted both local recurrence ( p = .005) and decreased overall survival ( p = .039), whereas PNI of small nerves predicted worse survival ( p = .002) but not local recurrence . The finding that PNI of large nerves carries greater prognostic significance is in agreement with Aivazian et al but differs from the studies by Fagan et al and Chinn et al who reported no association between nerve size and local recurrence. To determine the need for adjuvant RT, Brandwein–Gensler et al proposed a histologic risk assessment for early‐stage oral cavity squamous cell carcinoma.…”

“…One of the limitations of the existing literature pertaining to PNI is the lack of a standardized definition of or method for detecting PNI . Liebig et al proposed the most widely cited definition of PNI, according to which PNI is present when tumor cells are identified in any of the 3 layers of the nerve sheath or tumor is identified in close proximity to the nerve and involves more than one‐third of its circumference. However, other authors have defined PNI more broadly as tumor cells touching a nerve .…”

“…However, the maximum extent of PNI was associated with time to recurrence on multivariate analysis ( p < .021). Similarly, Aivazian et al performed a detailed evaluation of the histopathologic characteristics of PNI in 318 patients with oral cavity squamous cell carcinoma. Again, PNI had no significant prognostic value when classified as present or absent.…”

Patterns of recurrence in oral tongue cancer with perineural invasion

“…Several studies have shown that the presence of PNI alters prognosis in oral cavity squamous cell carcinoma (SCC) negatively (2–5) . While these findings support PNI as an adverse risk feature, it remains unclear exactly how PNI should be measured, whether PNI should be quantified rather than reported as a binary outcome, and how the identification of PNI should affect clinical management.…”

Significance of perineural invasion in locally advanced bucco alveolar complex carcinomas treated with surgery and postoperative radiation ± concurrent chemotherapy

“…In our study, 60% of the patients with PNI‐positive disease had either lymphovascular invasion or ECE compared with only 18% among PNI‐negative cases. Aivazian et al, in a study of 318 patients, concluded that multifocal PNI is associated with poor outcome even with postoperative radiotherapy suggesting consideration of therapeutic escalation particularly with involved nerves ≥1 mm. Conversely, a study reporting a retrospective histopathologic review of 142 patients with head and neck cancer showed PNI of nerves <1 mm to be an independent adverse prognostic factor …”