Contemporary Biology, Management, and Outcomes of Renal Medullary Carcinoma in Children and Adults: A Pediatric Surgical Oncology Research Collaborative Study.

Background: Renal medullary carcinoma (RMC) is an aggressive tumor associated with sickle cell trait. Despite treatment advances for other rare renal tumors, RMC survival remains poor. We aimed to describe the contemporary management and survival of children and adults with RMC.

Procedure: In this multicenter retrospective cohort study, Pediatric Surgical Oncology Research Collaborative sites searched their databases for patients diagnosed with RMC (2000-2022). Descriptive statistics were calculated and survival analyses performed using Kaplan-Meier and Cox regression.

Results: Thirty-four patients with RMC were identified. Median age was 19 years (IQR: 15-28; range: 7-52). Most were male (24/34; 71%), Black (27/32; 84%), had sickle cell trait or disease (30/33; 91%), presented with metastatic disease (27/34; 79%), and were symptomatic at presentation (32/34; 94%). Median overall survival (OS) was 24 months from diagnosis (16 months for children, 28 months for adults, p = 0.6). Receipt of platinum-based chemotherapy (23/34; 68%) was associated with significantly higher OS than other regimens (35 vs. 5 months, p < 0.001). Nephrectomy (24/34; 71%) was associated with significantly improved OS compared with non-operative management (34 vs. 7 months, p = 0.001). Immunotherapy, targeted therapy, or radiation therapy were not associated with significant differences in OS, nor were age, sex, race, sickle cell status, SMARCB1/INI-1, stage, nephrectomy approach, retroperitoneal lymph node dissection, gross residual disease, margins, or tumor size.

Conclusions: RMC survival remains poor despite newer therapies. Nephrectomy and platinum-based chemotherapy should be considered in locally advanced and metastatic disease. Coordinated international cooperative group studies are needed to meaningfully improve RMC survival.