Systemic therapy in patients with metastatic Xp11.2 translocation renal cell carcinoma.

Abstract

341 Background: Xp11.2 translocation renal cell carcinoma (RCC) is a unique RCC subtype with high malignant potential and poor prognosis, its natural course and response to systemic therapy are not fully understood. We analyzed the clinic features of this distinct entity and the benefit of systemic therapy in these patients. Methods: Between May 2006 and December 2019, 1113 consecutive patients diagnosed with RCC from Peking university cancer hospital (Beijing, China) were reviewed, data of the clinical characteristics and outcome of patients with metastatic Xp11.2 RCC were retrospectively collected. Tumor response to systemic therapy was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) criteria. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and overall survival (OS) distributions. Results: Metastatic Xp11.2 tRCC was found in 45 patients. The median PFS and median OS was 7.4 months (4.5 - 8.8) and 17.9 months (12.4 - 24.4), respectively. First-line treatment mainly included sunitinib (n = 14), sorafenib (n = 15), axitinib (n = 6), and pazopanib (n = 5), and the median PFS of these regimens were 7.4 months, 5.4 months, 9.4 months, 8.9 months, respectively. Two patients who received Vascular endothelial growth factor receptor - tyrosine kinase inhibitor (VEGFR-TKI) plus immune checkpoint inhibitor (ICI) as first line therapy had a PFS of more than 16.6 months and more than 25.6 months, respectively. Twenty-four patients received subsequent therapies, which included VEGFR-TKI/ICI, axitinib and mTOR inhibitor, the median PFS for these regimens was 8.5, 7.2 and 2.0 months, respectively. Patients with serous cavity effusion or IMDC poor risk groups had significantly shorter median PFS and median OS. Conclusions: Metastatic Xp11.2 tRCC is an aggressive disease. VEGFR-TKI agents appeared to demonstrate some efficacy, VEGFR-TKI/ICI combination might be a useful tool for the treatment of metastatic Xp11.2 tRCC.