Surgical salvage of recurrent T3 nasopharyngeal carcinoma: Prognostic significance of clivus, maxillary, temporal and sphenoid bone invasion

Abstract

Background: To study the efficacy of surgery for recurrent T3 nasopharyngeal carcinoma (NPC) and to determine the prognostic significance of various skull base bone invasion.

Method: Retrospective view of the surgical outcome for recurrent T3 NPC. Kaplan Meier and log rank tests were used to determine the 5-year overall and disease specific survival. Multivariate analysis was used to identify significant independent prognostic factors that affect the surgical outcome.

Results: Between 1990 and 2017, 208 patients with recurrent T3 NPC were recruited. Salvage surgery was performed via the endoscopic endonasal approach (n = 22, 10.6%), endoscopic transpterygoid approach (n = 63, 30.3%) and the maxillary swing approach (n = 123, 59.1%). Thirty-eight (18.3%) patients required vascular bypass. The skull base bone involved by the tumours included: maxillary sinus (n = 13), clivus (n = 36), pterygoid process (n = 61), sphenoid sinus (n = 30), petrous part of the temporal bone (n = 42) and a combination of the above (n = 26). The mean follow-up duration was 41.7 months. Multivariate analysis identified tumours involving with both cortexes of the clivus and the lateral wall of the sphenoid sinus, as well as positive bone resection margins as the significant independent prognostic factors for surgical outcome.

Conclusion: Outcome of surgical salvage is significantly worse for tumours that involve multiple bones at the skull base, particularly when both cortexes of the clivus and the lateral wall of the sphenoid sinus are invaded. Indication of aggressive surgery in such circumstances is controversial.

Keywords: Clivus; Nasopharyngeal carcinoma; Recurrent; Sphenoid bone; T3.