Clinicohistological characteristics of renal cell carcinoma in children: A multicentre study

Introduction: In this retrospective multicentre study, we compared the clinicohistological characteristics of renal cell carcinoma (RCC) between pediatric and adult patients. Methods: Data for patients who underwent radical or partial nephrectomy for RCC between 1988 and 2014 at multiple institutions were collected. Patients were divided into 2 groups according to age at diagnosis: pediatric patients (age <= 18 years) and adult patients (age >= 40 years). The groups were compared for clinical and pathologic variables, and survival analysis was performed. Results: The median follow-up period was 64 (range: 30-91) months for pediatric patients versus 44 (range: 19-59) months for adult patients (p = 0.026). Pediatric patients were mostly female (p = 0.003), had symptoms at presentation (p < 0.001), and had a high-stage tumour (p = 0.014) than adult patients. Among the symptomatic patients, gross hematuria was the most common symptom. The median tumour size was not different between groups. Regarding histologic types, pediatric patients had more papillary tumours (p < 0.001), more unclassified tumours (p < 0.001), and fewer clear cell carcinomas (p < 0.001). Five-year cancer-specific survival rates were 85% and 87.4% in pediatric and adult patients, respectively (log rank p = 0.901). Recurrence-free survival was better in adult patients, although this did not reach statistical significance (log rank p = 0.272). This study has several limitations, including its retrospective nature and the relatively small number of pediatric RCC cases. Conclusion: RCC in children is rare and is characterized by features that differ from those in adult RCC. Prognosis did not differ between groups.