Primary and Secondary Tumors of the Parotid Gland: Clinical Features and Prognosis

Simple Summary Malignant salivary gland tumors are rare, accounting for 0.05-2 per 100,000 inhabitants worldwide. The parotid gland represents the most frequent cancer site, and both primary and secondary malignant tumors can affect it. Primary cancer includes many histological types, while intraparotid metastases have usually a cutaneous origin. Because of the rarity and heterogeneity of parotid tumors, the prognosis is difficult to assess. The literature focused on specific primary tumors or secondary cancer. The aim of this retrospective observational study was to evaluate the clinical features and prognosis of malignant epithelial tumors of the parotid gland. In particular, a comparison between primary and secondary cancer and survival analyses were performed. Moreover, complications were recorded. Primary and secondary malignant tumors can affect the parotid gland. The aim of this retrospective study was to evaluate the clinical features and prognosis of malignant epithelial tumors of the parotid gland. In particular, a comparison between primary and secondary cancer and survival analyses were performed. Eighteen patients with primary cancer and fifteen with intraparotid metastasis from cutaneous squamous cell carcinoma were included. A chart review was performed to collect clinical data (age, sex, smoking, alcohol consumption, tumor stage, type of surgical procedure, complications, recurrence and death). The majority of primary tumors were early (T1-2 N0, 83%) with mucoepidermoid carcinoma being the most common (33%). Secondary tumors were mostly staged P2 (53%) and N0 (67%). Subjects with secondary tumors were older than those with primary cancer. Post-operative permanent facial palsy was observed in 5 patients (17%) with primary cancer and 9 (60%) with secondary tumors (p = 0.010). Two-year overall survival for primary and secondary parotid cancer was 76.58% and 43.51%, respectively (p = 0.048), while 2-year disease-free survival was 76.05% and 38.50%, respectively (p = 0.152). In conclusion, secondary cancer of the parotid gland has worse survival than primary tumors. In the future, the implementation of multimodality treatment of intraparotid metastases is necessary to improve oncologic outcomes.