Malignant tumors of the maxillary sinus: Prognostic impact of neurovascular invasion in a series of 138 patients

Background: Maxillary sinus cancer is a rare disease with heterogeneous biologic behavior. The pattern of neurovascular invasion is known to be an important prognosticator in head and neck cancers, but has not been studied in maxillary malignancies. Materials and methods: Patients undergoing surgery-based treatment with curative intent for a malignancy of the maxillary sinus at the Unit of Otorhinolaryngology – Head and Neck Surgery of the University of Brescia between November 2000 and October 2018 were included. A description of the characteristics of the patients, tumors, and treatments has been performed along with uni- and multi-variate analysis of prognostic factors. Tumors were classified based on the presence of perineural (P0/P1) and lymphovascular invasion (V0/V1) in 4 categories: P0V0, P1V0, P0V1, and P1V1. Results: One hundred-thirty-eight patients were included. Mean age at surgery was 61.0 years. Most patients (60.1%) were affected by non-salivary carcinomas, and most tumors (73.9%) were high-grade cancers. One hundred-seven (77.5%) tumors were classified as pT4. The large majority of patients received bi- or tri-modality treatment. Sixty-three (45.7%) cases were classified as P0V0, 32 (23.2%) as P1V0, 7 (5.1%) as P0V1, and 36 (26.1%) as P1V1. T category, nodal status, and neurovascular invasion were significantly associated with prognosis. Perineural and lymphovascular invasion were associated with the topographical growth of the tumor. Conclusions: Maxillary cancer is often diagnosed at an advanced stage and in most cases requires a multimodal approach. Perineural and lymphovascular invasion are frequent and have a different impact on prognosis and topographical extension of the tumor.