Clinical perineural invasion of the trigeminal and facial nerves in cutaneous head and neck squamous cell carcinoma: Outcomes and prognostic implications of multimodality and salvage treatment.

BACKGROUND: Clinical perineural invasion (PNI) of the trigeminal and facial nerves from cutaneous head and neck squamous cell carcinoma (cutaneous HNSCC) is a rare clinical entity that poses unique therapeutic challenges.

METHODS: A retrospective chart review of a skull base oncology database was performed of patients with the diagnosis of clinical PNI from a cutaneous HNSCC. Patients who were previously untreated underwent multimodal treatment entailing surgical resection and postoperative radiotherapy (PORT) and patients who were previously treated with radiotherapy underwent salvage surgical resection between the years 2006 and 2012. Survival outcomes, such as disease-free survival (DFS) and overall survival (OS), were analyzed and correlated with surgical factors, such as margin status, previous treatment, zone involvement, and trigeminal involvement (branch-specific), as well as the pretreatment and posttreatment pain scores.

RESULTS: Of 21 patients with clinical PNI from cutaneous HNSCC, 7 patients (33%) were previously treated for their disease with primary radiotherapy. Negative tumor margins were achieved in 18 patients (86%). Three of the 7 patients (43%) undergoing salvage surgery had positive margins. One-year and 3-year DFS for previously untreated patients was 91% and 67%, respectively, whereas 1-year and 3-year DFS was 72% and 28%, respectively, for the previously treated patients. Previous radiotherapy, ophthalmic nerve involvement, and positive margins portended poorer survival outcomes in this study.

CONCLUSION: The retrospective study of this rare clinical entity demonstrates that multimodal treatment can achieve favorable survival outcomes. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1280-1286, 2017.