Outcomes after Surgery for Sinonasal and Skull Base Squamous Cell Carcinoma: A Single-Institution Experience

Introduction: Squamous cell carcinoma (SCC) of the paranasal sinuses and skull base represents a rare pathology, accounting for only 5% of head and neck cancers and just 1% of cancers overall. SCCs are reported to account for between 30 and 70% of sinonasal malignancies in previous series. In this study, we aim to review the management and outcomes of sinonasal SCC at our institution.

Methods: Patients were identified from an existing institutional skull base tumor database from 1973 to 2015 following review board approval. SCCs were recorded in 138 cases from a total database of 454. Survival curves were calculated according to the Kaplan–Meier method, differences in survival using the log-rank test, and hazard ratios (HR) according to the Cox proportional hazards regression model. Only factors significant in the univariable analysis were included in the multivariable analysis. For patients treated between 1998 and 2015 (n = 107), peripheral blood data were available (<1 month of surgery) and was used to calculate the neutrophil-to-lymphocyte ratio (NLR). We stratified patients into NLR high versus low using the median NLR within the cohort as cutoff. The follow-up interval was calculated in months from the date of initial curative surgery.

Results: From the institutional skull base database of 454 patients, 30.3% (138) were SCC. Median age was 55.5 years (range: 21–86 years). In total, 63.8% (88) were male. Tumor sites were 37.0% (51) nasal cavity, 31.9% (44) maxillary, 15.9% (22) ethmoid, 9.4% (13) skin, 1.4% (2) orbit, and 4.3% (6) at other sites. The majority were primary tumors 81.2% (112), rather than recurrent 18.8% (26). Orbital invasion was recorded in 31.2% (43), and intracranial invasion in 26% (36). Patients were staged as T1 in 8.7%, T2 in 10.1%, T3 in 16.7%, and T4 in 60.9%. Neck dissection was completed as part of surgery in 13% (18), with neck nodal metastases seen in 4.3% (6) of the total group. Positive pathological margins were recorded in 33.3% (46), and negative margins in 56.5% (78). Adjuvant treatment with radiotherapy alone was used in 54.3% (75) of cases and chemoradiotherapy in 16.7% (23). Five-year overall survival (OS) and disease-specific survival (DSS) were 57.7 and 62.7% ([Fig. 1]). Five-year local, regional, and distant recurrence-free probabilities were 65.2, 92.4, and 82.7%, respectively ([Fig. 2]). OS was significantly reduced in patients with high NLR (e.g., 5-year OS was 67.8% in the low NLR [<2.95] group versus 52.2% in the high NLR [≥2.95] group). In multivariable analysis (after showing significance in the univariable analysis), the main variables that predicted OS were age (HR: 1.030, 95% CI: 1.003–1.058), skull base resection (HR: 1.580, 95% CI: 0.819–3.051), pT3–T4 staging (HR: 1.699, 95% CI: 0.648–4.457), margin status (HR: 1.695, 95% CI: 0.919–3.126), and high NLR (HR: 1.591, 95% CI: 0.865–2.925; [Fig. 3]).

Conclusion: We highlight our institution's experience with sinonasal and skull base SCCs. Oncological outcomes are noted to be mostly affected by age, need of skull base resection, advanced stage, positive margins, and high NLR.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
12 February 2021