Clinicopathologic features of Xp11.2 translocation renal cell carcinoma and its response to target therapy.

Abstract

e16559 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 translocation RCC was found in 41 cases. The median PFS and Median OS was 6.3 months (4.4 - 8.8) and 17.3 months (12.4 - 21.8) for the whole cohort, respectively. First-line treatment mainly included sunitinib (n = 12), sorafenib (n = 13), axitinib (n = 6), and pazopanib (n = 4), and the median PFS of these regimens was 5.4 months, 5.1 months, 9.4 months, 8.3 months, respectively. Twenty-three patients received subsequent therapies, the median PFS and the median OS was 4.3 months and 12 months for the second-line therapy(n = 21), 4.3 months and 14.1 months for the third-line therapy(n = 11), 2.4 months and 9.6 months for the fourth-line therapy(n = 6). Conclusions: Metastatic Xp11.2 translocation RCC is an aggressive disease. Vascular endothelial growth factor receptor - tyrosine kinase inhibitor (VEGFR-TKI) agents appeared to demonstrate some efficacy, the combination of VEGFR-TKI and immune checkpoint inhibitor (ICI) might be a useful tool for the treatment of metastatic Xp11.2 translocation RCC.