Oncological outcomes of parotid gland malignancies: a retrospective analysis of 74 patients

Introduction: Salivary gland malignancies are rare neoplasms whose management has been evolving over the last two decades. Nevertheless, patient outcomes have not improved accordingly. Objective: In the present paper, factors and variables that could influence Overall, Disease-Specific and Disease-Free Survival, and Loco-Regional Control were analyzed. Methods: Chart data from 74 patients who underwent parotid gland surgery were retrospectively analyzed and stratified for tumor histology, grading, size, pT stage, pN stage, extracapsular spread, involved salivary gland lobe, and age at diagnosis. Major outcomes were estimated at 5 years by Kaplan-Meier curves. Results: Advanced stage, high grade, and lymph nodes involvement greatly impaired patient outcomes. Furthermore, in our cohort, the age at diagnosis ≥ 55 was a cause of poorer disease survival likely due to a different distribution in tumor histotypes between older and younger patients. Despite the two groups were homogeneous for the numerosity of squamous cell carcinomas, older patients were more rarely affected by mucoepidermoid and acinic cell carcinomas, which have generally better prognosis. Finally, patients aged ≥ 55 had a more frequent pathological involvement of the deep lobe of the parotid gland if compared to the younger counterpart. Conclusion: The rarity of some salivary gland tumor histotypes requires further high-number series to fully understand the prognostic factors for both patient survival and recurrence development. In our cohort, the age at diagnosis ≥ 55 raises concerns that play crucial roles in disease survival shortening.