Nasal Cavity and Paranasal Sinus Cancers

Introduction/Background The paranasal sinuses consist of the maxillary, ethmoid, sphenoid, and frontal sinuses. They communicate with the nasal cavity in the midline and all structures together form a group of air-filled cavities where cancers can arise, grow, and spread without encountering significant barriers to local extension. Cancers of the paranasal sinuses and nasal cavity are rare malignancies, accounting for 3%–5% of all head and neck cancers and <1% of all cancers [1-3]. The maxillary sinus is the most common site of paranasal sinus cancers (60%–70% of cases), followed by the nasal cavity (20%–30%), ethmoid sinus (10%–15%), and frontal and sphenoid sinuses (1%–2%). These are to be distinguished from skin cancers with deep erosion or nasal vestibule/nasal sill cancers with posterior extension. Due to the air space and cavities in the sinonasal region, these cancers are generally asymptomatic in early stages and are often not diagnosed until they are locally advanced. There are a wide variety of tumor types within the paranasal sinuses and nasal cavity, but as in other locations in the head and neck, squamous cell carcinoma predominates, accounting for >80% of paranasal sinus cancers [2,4]. The 5-year overall survival in patients with squamous cell carcinoma of the paranasal sinuses is approximately 50%, 30%, and 15% among those with localized, regional, and distant disease, respectively [3]. Tobacco use is a significant risk factor for squamous cell carcinomas, and exposure to wood dust, glues and adhesives, and pollutants is associated with adenocarcinomas.