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

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.