Background
Perineural invasion (PNI) is associated with survival in oral cavity squamous cell carcinoma (OCSCC). There is evidence to suggest that PNI that is extratumoural in location may be more significant, but currently this is not designated as a core reporting parameter. The primary aim of this study is to evaluate the prognostic ability of PNI including PNI location in early-stage OPSCC.
Methods
Retrospective study of 172 patients with pT1/T2N0 TNM8 OCSCC. Slides were re-reviewed in cases reported as having PNI to classify the location as intratumoural (IT) and/or extratumoural (ET). Univariate and multivariate analysis assessing impact of pathological features on survival outcomes was performed.
Results
On univariate analysis, IT PNI was significantly associated with locoregional recurrence (LRR) (odds ratio 2.38, 95% CI 1.07-5.32, p=0.033), but was not significant for disease-specific survival (DSS) or overall survival (OS). In contrast ET PNI was predictive of LRR (odds ratio 11.22, 95% CI 3.71-33.97, p<0.0001), DSS (odds ratio 21.33, 95% CI 5.93-76.79, p<0.0001) and OS (odds ratio 6.87, 95% CI 2.60-18.15, p=0.0001). These findings were maintained on multivariate analysis.
Conclusion
ET PNI is strongly predictive of survival outcomes. These findings support the addition of PNI location as a required data element for reporting.
Shima Mohamed1, Ryan O’ Sullivan2, Justin Hintze2, Deirdre Callanan2, Patrick Sheahan2,3, Linda Feeley1,3
1 Department of Pathology, Cork University Hospital, Cork
2 Department of Otolaryngology Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork
3 ENTO Research Unit, College of Medicine and Health, University College Cork, Cork