Adult genitourinary sarcomas: A single-centre experience over 25 years.

person Abdul Baseet Arham Department of Urology, University of Iowa, Iowa City, IA info_outline Abdul Baseet Arham, Michael A. O'Donnell, Sarah L. Mott

Authors person Abdul Baseet Arham Department of Urology, University of Iowa, Iowa City, IA info_outline Abdul Baseet Arham, Michael A. O'Donnell, Sarah L. Mott Organizations Department of Urology, University of Iowa, Iowa City, IA, University of Iowa Holden Comprehensive Cancer Center, Iowa City, IA Abstract Disclosures Research Funding No funding sources reported Background: Genitourinary sarcomas are a rare entity. This study is a retrospective review of the patient characteristics, types of adult GU sarcomas, treatments and outcomes in a single institution over the past 25 years. Methods: Survival probabilities were estimated and plotted using the Kaplan-Meier method. Estimates along with 95% pointwise confidence intervals were reported. Recurrence-free survival (RFS) is defined as time from when the patient was disease-free to recurrence. Otherwise, patients were censored at last disease evaluation. OS was defined as time from when the patient was disease-free to death due to any cause. Patients still alive were censored at last known alive. Results: 29 patients presented with various types of GU sarcomas, with the majority being paratesticular tumors (n = 22, 75.9%). Others included bladder leiomyosarcomas (n = 5), prostatic leiomyosarcoma (n = 1), renal leiomyosarcoma (n = 1). Median age for diagnosis was 51 years (range: 21-79) for leiomyosarcoma vs 61 (range: 36-89) for liposarcoma. Among the paratesticular tumors majority were (n = 16) were liposarcoma, remaining 5 being leiomyosarcoma and 1 being rhabdomyosarcoma. Majority tumors were stage III and above (n = 16, 55.17%), high and intermediate grade (65.51%). All tumors were resected ± adjuvant therapy (n = 4). Leiomyosarcomas had a higher stage (66%) and grade (83%) at diagnosis, recurrence rate was also higher at 37.5% (vs 6.6% for liposarcoma) along with a higher mortality (41.6%). Commonest site of recurrence for leiomyosarcoma was the lungs (n = 3, 100%). Treatment for recurrence commonly involved radiotherapy, pembrolizumab etc. Paratesticular liposarcomas were found to be associated with a lipomatosis syndrome with n = 5 (31.25%) having lipomas elsewhere in the body and n = 2 (12.5%) patients having had previously resected spermatic cord lipoma. Paratesticular sarcomas often required (n = 15, 68%) revision surgery due to being initially diagnosed as a hernia, cord lipoma or hydrocele and requiring high ligation of the cord with hemiscrotectomy and radical orchiectomy ± LND on revision surgery, which often demonstrated a focus of residual tumor in liposarcomas (n = 5, 31%). N = 4 patients (25%) had positive margins in spite of revision surgery. Majority of these were MDM2+ positive on FISH (n = 9, 56%). Overall, GU sarcomas had an RFS of 63% (53-94%) and OS of 82% (53-94%) at 36 months since NED was achieved. The median length of follow-up was 19.9 months for leiomyosarcoma, 33.8 months for liposarcoma. Conclusions: Leiomyosarcomas in adults have worse outcomes compared to other GU sarcomas especially if it originates in the bladder. RFS since NED. 12 months 24 months 36 months 95% (68-99%) 83% (56-94%) 35-81%)