Montgomery, Brian

430 Background: Malignant melanoma of the female urethra accounts for less than 1% of all melanoma and less than 4% of urethral cancer. Due to limited data regarding management and outcomes of this condition, we evaluated the management and outcomes of urethral melanoma in females over the last 20 years at our institution. Methods: Patients were identified via retrospective review of the medical record. Those with metastatic disease at initial diagnosis were excluded. We evaluated primary and adjuvant treatments, disease recurrence and overall survival. Results: Fifteen women (median age 71, range 55, 82) were identified. Majority of masses involved the distal urethra (86.6%). All patients underwent primary surgical resection (60.0% partial urethrectomy, 40.0% radical urethrectomy). Disease recurrence and metastatic spread occurred in 73.3% (median 7 months, IQR 4, 12) and 60% (median 6 months, IQR 3, 9) of patients, respectively. 90.9% of patients with recurrence received adjuvant therapy: 5 chemotherapy and radiation, 4 chemotherapy only, 1 anterior exenteration. Of the 9 patients undergoing chemotherapy, treatment regimens were varied and included checkpoint inhibitors (2/9), platinum-based chemotherapy (3/9), tyrosine kinase inhibitors (2/9), taxels (2/9), and alkylating agents (1/9). Median overall survival was 27 months (IQR 7.5, 57.5). Conclusions: Malignant melanoma of the urethra is locally aggressive with a high likelihood of recurrence and metastases resulting in poor long-term survival. Despite high recurrence rates, our data highlight the lack of consensus adjuvant treatment regimens. Future research is required to identify neoadjuvant, combination, and adjuvant treatment approaches to improve disease outcomes.