Comparison of Parotidectomy with Observation for Treatment of Pleomorphic Adenoma in Adults

Abstract

Importance: There is no consensus regarding optimal management of pleomorphic adenoma in adults. Objectives: To compare parotidectomy with observation for the management of pleomorphic adenoma in patients 50 years or older by age. Design and Setting: This decision analytical model was performed from November 21, 2019, to June 15, 2020, using a Markov model. Model variables and ranges were selected based on a literature review. A 1-way sensitivity analysis was performed to evaluate the age threshold at which each algorithm, either upfront elective parotidectomy or observation, would be favored. A Monte Carlo probabilistic sensitivity analysis using variable ranges was then performed 5 times with patients in the model assigned a starting age of 50, 60, 70, 80, and 90 years to assess how age at diagnosis would be associated with the model results. Main Outcomes and Measures: Model outcomes were measured with quality-adjusted life-years (QALYs). Results: In the study models, the age thresholds at which observation became more beneficial than parotidectomy were 88.5 years for patients with superficial lobe tumors (5.37 QALYs in favor of parotidectomy below this age, and 5.37 QALYs in favor of observation above this age) and 83.4 years for patients with deep lobe tumors (7.51 QALYs in favor of surgery below this age, and 7.51 QALYs in favor of observation above this age). There was no significant difference in outcomes between parotidectomy and observation among patients aged 70 to 80 years. Conclusions and Relevance: This study suggests that the outcomes associated with parotidectomy and observation are similar at 70 years or older among patients with pleomorphic adenoma and that observation may be the favorable treatment in that age group.