(0674) Locoregional Recurrence in Periauricular Cutaneous Squamous Cell Carcinoma Undergoing Temporal Bone Resection

Introduction: Advanced cutaneous squamous cell carcinoma (SCC) of the periauricular structures often requires lateral temporal bone resection (LTBR). Locoregional recurrence rates and patterns of these tumors are poorly understood.

Methods: A single-institution, retrospective review was performed from 2011-2021 of all periauricular SCC requiring LTBR. Patient histories, operations, histopathologies, staging, adjuvant treatments, and follow-up data were collected. Kaplan-Meier curves and Cox-proportional hazard models were generated of 5-year locoregional recurrence.

Results: A total of 67 primarily White (98.5%) male (86.6%) patients with mean age 72.4 years were included. Most patients required total auriculectomy (64.2%) and total parotidectomy (68.7%) with 46.3% requiring facial nerve sacrifice. Almost all patients underwent neck dissection of level II (100%) and III (94%). Most tumors represented recurrent disease (64.2%), many of which were intraparotid metastases (28.4%). Tumors had median dimension of 4.4 cm and were often poorly-differentiated (46.2%) with PNI (43.3%) and LVI (34.3%). Overall pathologic AJCC staging was stage III-IV in 89.6%. Final margins were positive in 13.4% of resections. Pathologic nodal disease was identified in 34.3% of cases, most of which were intraparotid (87%). Adjuvant radiation was administered in 67.2% of overall cases and 88.9% of those who had not had prior radiation. Median follow-up and overall survival were 20.7 months and 54.7 months, respectively. Recurrent disease was identified in 19.4% of patients at median 8.6 months, most of which were at the prior tumor bed (92.3%) and rarely cervical nodes (3%). The final Cox-proportional hazard model of 5-year locoregional recurrence identified immunosuppression (OR [95%CI] = 4.8 [1.5-15.3]) and PNI (OR [95%CI] = 2.7 [0.9 – 8.5]) as predictors.

Conclusions: Recurrence of periauricular SCC is predominantly in the tumor bed and associated with PNI and immunosuppression. Prospective studies comparing surgical and adjuvant therapies are warranted.