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

Abstract

Perineural invasion (PNI) is widely regarded as a negative prognostic factor in head and neck squamous cell carcinoma (HNSCC). Treatment guidelines recommend adjuvant radiotherapy (RT) for patients with adverse pathologic features, including PNI. The purpose of this study was to systematically review the literature to determine if patients with PNI as their only indication for adjuvant therapy benefit from adjuvant RT. In total, 339 abstracts were reviewed for relevance leaving 85 articles, which were evaluated in detail. Thirteen retrospective studies addressed the role of adjuvant RT for patients with PNI. Evidence is lacking to recommend adjuvant RT for all patients with HNSCC with PNI. However, the literature suggests that large nerve or multifocal PNI may predict worse outcome and may be a more appropriate indication for adjuvant therapy. We advocate that patients decide whether to undergo adjuvant therapy after a discussion of the limitations of current evidence. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2350-E2357, 2016.

Early oral cavity cancer: The prognostic factors and impact of adjuvant radiation on survival

“…Barring close margin there are no prospective studies demonstrating benefit of adding adjuvant radiation based on poor prognostic factors. 15 Similarly, in the present study PNI was not found to be significant prognosticator on multivariate analysis both for recurrences and DSS. Present study analyzes prognostic factors in EOCC and the impact of adjuvant RT on survival with respect to DOI.…”

Multifocal perineural invasion is a better prognosticator than depth of invasion in oral squamous cell carcinoma

“…In addition to being associated with other adverse features, PNI has been shown to predict both reduced survival and increased local recurrence independently . The rates of PNI are reported to be in excess of 30% in OSCC, even in early stage disease . However, there is no consensus on whether all patients with PNI require adjuvant therapy in the absence of additional adverse histopathologic findings …”

“…The rates of PNI are reported to be in excess of 30% in OSCC, even in early stage disease . However, there is no consensus on whether all patients with PNI require adjuvant therapy in the absence of additional adverse histopathologic findings …”

Adverse pathologic features in T1/2 oral squamous cell carcinoma classified by the American Joint Committee on Cancer eighth edition and implications for treatment

“…5 This served to distinguish the difference between thick exophytic tumors with limited depth of invasion from those with limited diameter but extensive infiltration, previously identified as a limitation of the previous AJCC TNM classification system. 12 The role of lymphovascular invasion has been equally controversial, [13][14][15] with the implications for adjuvant therapy remaining unclear. Perineural invasion (PNI) was shown to carry a higher risk of locoregional recurrence and decreased survival in several studies 7-11 ; however, the heterogeneity in the subsites described and the treatment, specifically the role of elective neck dissection and postoperative radiotherapy (PORT), led to a lack of a consensus, as reflected in a recent systematic review.…”