Salvage endoscopic nasopharyngectomy for recurrent nasopharyngeal carcinoma in a non-endemic area

Abstract

Purpose: To analyze oncological outcomes of endoscopic surgical treatment of locally recurrent EBV-related undifferentiated non-keratinizing nasopharyngeal carcinoma (uNK-NPC) in a non-endemic area.

Methods: Retrospective review of patients affected by recurrent uNK-NPC treated with nasopharyngeal endoscopic resection (NER) in a tertiary-care referral center from 2003 to 2022, by evaluating survival rates, prognostic factors, and follow-up strategies.

Results: The oncological outcomes of 41 patients were analyzed, over a mean follow-up period of 57 months. The 5-year overall, disease-specific, and disease-free survival of the cohort were 60.7% ± 8.9%, 69% ± 9%, and 39.7% ± 9.2%, respectively. The local (rT) and regional (rN) extension of recurrent disease, stage of disease, and status of resection margins appeared to significantly influence survivals. After a mean follow-up period of 21 months, a further recurrence after NER was observed in 36.6% of cases. Skull base osteonecrosis induced by previous irradiation and post-surgical bone remodeling represent the major challenges for early detection of further local relapses during postoperative follow-up.

Conclusion: NER appeared as a safe and effective treatment for recurrent uNK-NPC. The adequate selection of patients eligible for NER is essential, to maximize the chances to cure and minimize the risk of local complications.

Keywords: EBV; Endoscopic nasopharyngectomy; Head and neck oncology; Nasopharyngeal carcinoma; Skull base.

Fig. 1

Overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) stratifying patients according to tumor stage at the moment of surgical treatment

Fig. 2

Disease-specific survival (DSS) and disease-free survival (DFS) stratifying patients according to status of resection margins

Fig. 3

Local recurrence free survival (RFST) stratifying patients according to recurrence local extension (T), tumor stage at the moment of surgical treatment and status of resection margins (R)

Fig. 4

Flowchart indicating the results of examinations performed during follow-up

Fig. 5

Radiological and clinical follow-up performed nine months after NER type 3 (right side) and ipsilateral MRND for recurrent uNK-NPC (rpT1N3cM0) in a 48 year old patient. An area of focal contrast-enhancement (a) and ¹⁸FDG uptake (b) was evident at the level of the left portion of the nasopharynx (white arrow), corresponding at the endoscopic evaluation (c) to a small swelling (black asterisk) below the left pedicled nasoseptal flap (white dotted line). Imaging investigations showed another area of diffuse contrast-enhancement (d) and ¹⁸FDG uptake (e) at the level of the right pterygoid area (white arrowheads) which, at the endoscopic evaluation (c), appears as an area of exposed necrotic bone and granulations (black triangle). Biopsies were taken from both areas of suspect signal, resulting in local recurrence of uNK-NPC at the level of the left nasopharynx and chronic inflammation at the level of right pterygoid, due to underlying osteonecrosis (white crosses) as demonstrated by CT scan (f). ET Eustachian tube, HP hard palate, LSS left sphenoid sinus, tIT tail of inferior turbinate, tMT tail of middle turbinate