Systemic Therapy in Patients With Metastatic Xp11.2 Translocation Renal Cell Carcinoma

Background: Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) is a unique subtype with poor prognosis, its response to systemic therapy is not fully understood, we evaluated the benefit of systemic therapy in these patients.

Patients and methods: Between May 2006 and December 2019, patients diagnosed with Xp11.2 tRCC from Peking university cancer hospital were collected. 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, VEGFR-TKI and mTOR inhibitor. The ORR and median PFS was 33% and 7.1 months, 7.7% and 4.3 months, 0% and 2.1 months for these treatments, respectively. The estimated median OS was 17.3 months (95% CI, 11.2 to not reached) in patients with TKI/ICI treatment and 11.0 months (95% CI, 6.1 to not reached) without TKI/ICI treatment in subsequent therapies (P = .04). Patients with serous cavity effusion or IMDC poor risk groups had significantly shorter median PFS and median OS.

Conclusion: 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.