Factors and Outcomes Associated With Temporal Bone Resection for Primary Parotid Malignancy

Objective(s): Although parotid cancer invading into the temporal bone makes up only a small fraction of all parotid cancers, it is more common and relatively understudied compared with primary cancer of the external auditory canal. The objective of this study was to determine what factors are associated with receiving parotidectomy with temporal bone resection (TBR) and the immediate postoperative outcomes. Methods: We reviewed the National Cancer Database (2004–2015) for patients with primary parotid malignancy who received parotidectomy with or without TBR. Patient demographic, clinical, and perioperative variables were collected and then compared. Multivariate logistic regression was performed to determine factors associated with receiving TBR. Results: We identified 134 patients who received parotidectomy with TBR and 16,595 who received parotidectomy only. Reported in terms of odds ratios (95% confidence interval), our multivariate model showed having surgery at an academic facility (1.91 [1.34–2.71], P <.001), clinical stage III or IV (7.48 [1.65–33.96] and 31.37 [7.61–129.32], P =.009 and P <.001, respectively), histologic grade II to IV (4.36 [1.51–12.57], 4.31 [1.53–12.15], and 6.74 [2.26–20.13], P =.006,.006, and.001, respectively), and adenoid cystic histology (3.23 [2.02–5.17], P <.001) were significantly and independently associated with receiving TBR. There was no significant difference in 30-day readmission, or 30-day or 90-day mortality, but the rate of positive surgical margins was significantly higher in those who underwent TBR. Conclusion: Demographic variables are not significant factors for receiving TBR. Tumor characteristics, such as clinical stage and histologic type, and receiving surgical treatment at an academic facility were more strongly associated with receiving TBR. Level of Evidence: 3 Laryngoscope, 131:E2461–E2468, 2021.