Multidisciplinary Management of Children with Non-Wilms Renal Tumor: A Real-World Evidence from a Tertiary Cancer Care Center in Southern India

Abstract Non-Wilms renal tumors (NWRTs) are a rare group of disorders comprising only 10 to 20% of all pediatric renal tumors. Their timely and accurate identification is critical, as therapeutic approaches differ markedly from those for Wilms tumor. Due to their rarity, the NWRTs remain less well-characterized than Wilms tumor. This study seeks to outline the demographic profile, clinical features, treatment strategies, and survival outcomes of children with NWRTs managed in our center. We conducted a retrospective study on children diagnosed and treated as NWRTs between January 2000 and December 2023 at the pediatric oncology unit of a tertiary care cancer center in Southern India. We categorized the NWRTs into three therapeutic groups: group I: benign tumors requiring surgery only; group II: malignant tumors requiring surgery only; and group III: malignant tumors requiring surgery and chemotherapy—more intensive than the Wilms tumor regimen, with or without radiotherapy During the study period, 17 children (19% of all renal tumors) were diagnosed with NWRTs in our unit. The distribution of histological variants within our study cohort was as follows: clear cell sarcoma of kidney (n = 6; 35%); renal cell carcinoma (n = 4; 24%), primitive neuroectodermal tumor (n = 2; 12%), non-rhabdomyomatous soft tissue sarcoma (n = 2; 12%), mesoblastic nephroma (n = 2; 12%), and multicystic nephroma (n = 1; 5%). Eleven patients underwent upfront nephrectomy, while six children received preoperative chemotherapy followed by delayed nephrectomy. Pretherapy biopsy was performed in only six patients in our study cohort. The study participants had a median follow-up duration of 97.5 months (range: 25–136 months). The 5-year event-free survival (EFS) and overall survival (OS) rates for the entire study cohort were 59% (95% confidence interval [CI]: 32–78%) and 62% (95% CI: 34–81%), respectively. Group I demonstrated excellent outcomes, with both 5-year EFS and OS rates at 100%. The 5-year EFS and OS rates were both 75% (95% CI: 13–96%) among the participants belonging to group II. The 5-year EFS and OS rates of group III patients were 40% (95% CI: 12–67%) and 43% (95% CI: 12–71%), respectively. NWRTs represent a rare and diverse group of renal tumors among children. Early and precise diagnosis of NWRTs, coupled with individualized, multidisciplinary treatment strategies, is vital to achieving better outcomes.