Comparative Clinicopathologic Characteristics and Outcomes of Paediatric and Adult Xp11 Translocation Renal Cell Carcinomas: a Retrospective Multicentre Study in China

This study aimed to compare the clinicopathologic features and prognosis in patients with Xp11 translocation renal cell carcinomas (RCCs). In total, 8083 RCCs were screened at five centres from January 2007 to December 2018, including 8001 adults (>= 18 years) and 82 children (<18 years). Finally, 73 adults and 17 children were identified as Xp11 translocation RCCs, accounting for 1.1% (90 of 8083) of the RCCs. However, 4 children and 1 adult were excluded because of loss to follow-up when performing the survival analysis. The proportion of paediatric and adult Xp11 translocation RCCs was 20.7% (17 of 82) and 0.9% (73 of 8001) of RCCs, respectively, and the incidence in children and adults was significantly different (P<0.01). Lymph node positivity (LN+) most commonly occurred in children (58.8%) compared with adults (28.8%; P=0.02), but children with LN+ showed significantly higher five-year overall survival and progression-free rates (OS: 75.0%; PFS: 64.8%) than adult patients (OS: 40.3%; PFS: 0%) (log-rank P-PFS<0.01; P-OS=0.04). Multivariable analysis indicated that local lymph node metastasis was associated with both PFS (HR=0.10; 95% CI 0.02-0.51; P=0.01) and OS (HR=0.11; 95% CI 0.01-0.98; P=0.04) in adults. Adult patients with LN+ may indicate a worse prognosis than paediatric patients.