Impact of positive margins on outcomes of oropharyngeal squamous cell carcinoma according to p16 status.

Background: Currently, positive surgical margins in head and neck cancer are considered to be an indicator for postoperative chemoradiotherapy (CRT) over radiotherapy (RT) alone. However, there are less data regarding the impact of margin status on human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC). Methods: We performed a retrospective review of 55 patients with oropharyngeal SCC undergoing primary surgical treatment. The impact of margin status on disease-specific survival (DSS) was studied according to p16 status. Results: Twenty-one patients had positive margins. Adjuvant treatment in these cases was CRT (n = 6), RT alone (n = 14), and none (n = 1). Among p16-negative patients, positive margins and dysplasia at margins predicted significantly worse DSS. Among patients with p16-positive disease, margin status had no impact on DSS. Conclusion: Patients with p16-positive oropharyngeal SCC and positive margins after excision maintain a low risk of recurrence despite most receiving RT alone as adjuvant treatment. These findings raise questions regarding the additional benefit of postoperative CRT in this group.