Effect of adjuvant radiotherapy on the local recurrence of oral squamous cell carcinoma with perineural invasion: A systematic review

Abstract

Objectives of the Review:The decision whether to include postoperative radiotherapy on patients with oral squamous cell carcinoma depends on the risk of local recurrence. The objectives of this study were to systematically review literature on whether perineural invasion in oral squamous cell carcinoma patients is associated with higher local recurrence rates and whether local recurrence is influenced by the administration of postoperative radiotherapy in patients presenting with perineural invasion. Type of Review: Systematic review.Search Strategy: Embase, PubMed, Web Of Science.Evaluation Method: The databases above were searched for studies that analysed: the treatment of oral squamous cell carcinoma patients with perineural invasion, local recurrence and postoperative radiotherapy. The data of seven studies were analysed qualitatively. Results:The overall quality of the studies was moderate to low. There was no evidence of the effect of postoperative radiotherapy on local recurrence rates in patients presenting with perineural invasion. Some evidence suggests that local recurrence rates may increase in cases of multifocal perineural invasion, especially if nerves >1 mm are involved but these data should be interpreted with caution due to the low-quality evidence.Conclusions: High-quality evidence regarding the prognostic value of perineural invasion and the impact of postoperative radiotherapy in patients presenting with perineural invasion is lacking in the literature, making it difficult to select a postoperative strategy for early-stage tumours.

Positive survival trend in metastatic head and neck cutaneous squamous cell carcinoma over four‐decades: Multicenter study

“…PNI was a significant predictor of both DSS ( P = .001) and OS ( P < .001) on multivariate analysis as were the number and size of metastatic nodes. Increasing rates of PNI, however, likely reflects reporting bias with routine implementation of synoptic reporting as has been described for nodal yield . There was also no evidence to suggest that patients were presenting at an earlier stage to explain the improved prognosis.…”

“…Increasing rates of PNI, however, likely reflects reporting bias with routine implementation of synoptic reporting as has been described for nodal yield. 18 There was also no evidence to suggest that patients were presenting at an earlier stage to explain the improved prognosis. In fact, the proportion of immunosuppressed patients increased over time suggesting that improvements in survival may be related to improved management of metastatic HNcSCC.…”

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

“…Whether or not PNI in isolation warrants adjuvant radiotherapy has been the subject of debate. Several systematic reviews have consistently reported a lack of evidence to support the notion that adjuvant RT reduces local recurrence or death in OSCC with PNI . However very few studies account for other adverse risk factors or quantify the number of nerves involved.…”

“…Depth of invasion (DOI) and extranodal extension (ENE) have been incorporated into the recent eighth edition of the American Joint Committee on Cancer (AJCC8) staging manual for OSCC . The effects of perineural invasion (PNI) on local disease control and mortality have been explored in multiple studies . 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 …”