Predictors of distant metastases in sinonasal and skull base cancer patients treated with surgery

Objectives: Sinonasal and skull base tumors comprise a heterogeneous group of malignancies with a significant rate of distant recurrence (DR). The aim of this study was to analyze tumor and host factors, including pretreatment neutrophil-to-lymphocyte ratio (NLR), that predict DR in these patients. Materials and Methods: We retrospectively reviewed sinonasal tumors and/or tumors involving the skull base treated with surgery between 1973 and 2015 (n = 473). We stratified NLR using the top 5 percentile as cutoff. Factors predictive of outcome were determined by Cox proportional hazards model. Results: Most tumors were primary (81%) and 67% had skull base resection. The most common site was the nasal cavity (37%) and the most common histology was squamous cell carcinoma (34%). Most patients presented with advanced primary tumor stage (pT3/T4; 80%) and most had no regional neck disease (pNx/N0; 93%). A total of 104 patients developed DR. The 5-year overall and disease-specific survival for patients who developed DR were 36.4% and 35.8%, compared to 69.0% and 74.9% for patients who did not. Patients with DR had a higher percentage of NLR-high patients compared patients without DR (11% vs 3%, p = .006). In a multivariable analysis, melanoma histology (HR = 5.469, 95% CI 3.171-9.433), pT3/T4 (HR = 2.686, 95% CI 1.150-6.275), pN+ (HR = 6.864, 95% CI 3.450-13.653), and NLR-high (HR = 3.489, 95% CI 1.593-7.639) were independent predictors of DR. Conclusion: Melanoma histology, pT, pN, and high NLR predict DR, suggesting that both tumor and host factors need to be considered. NLR may act as a surrogate marker of the hosts immune system.