Squamous cell carcinoma arising on sinonasal inverted papilloma: survival outcomes of 27 patients treated with endoscopic endonasal resection

Objectives
Inverted papillomas can be associated synchronously or metachronously to invasive squamous cell carcinoma in 5-10% of cases. The mortality rate has been reported to be around 40%. The aim of the present study is to analyzing the clinical features, treatment modalities and survival outcomes in this specific subgroup of patients.
Methods
A retrospective analysis was carried out on patients with inverted papilloma associated to squamous cell carcinoma endoscopically managed over the past 22 years, at two university centres following a uniform policy.
Results
Twenty-seven patients were treated between November 1991 and August 2013. The tumors were staged as T1 (5/27), T2 (7/27), T3 (8/27), T4a (2/27) and T4b (5/27). All patients underwent surgery with an exclusive endoscopic endonasal resection (23 cases), a cranio-endoscopic resection (3 cases), a combined endoscopic-osteoplastic flap procedure (1 case). Subsequently, 11 patients underwent adjuvant radiotherapy, 1 adjuvant chemotherapy and 2 concomitant radio-chemotherapy. The follow-up ranged from 130 to 5 months (mean: 46.9 months). 21 patients had no evidence of disease, 1 patient was alive with disease, while 5 patients developed
distant metastases and died of disease. The 5-years overall survival in our series was 66.8% (22/27).
Conclusion
In correctly selected patients, the endoscopic endonasal approach offers a less invasive alternative than resection by an open approach, with acceptable morbidity. Adjuvant radiotherapy with or without chemotherapy should be indicated in advanced disease or in presence of close or positive margins. Recurrent disease can develop after prolonged period of time, thus long term follow-up, is recommended.