Rare non-Wilms' tumors in children

Non-Wilms' renal tumors in children: experience with 139 cases treated at a single center

Background

Pediatric non-Wilms renal tumors (NWRTs), which comprise a small proportion of renal tumors, are a heterogeneous group of neoplasms with variable malignant potential, mortality, and response to treatment. We performed this study to determine the clinical characteristics, management and prognosis of children with Pediatric NWRTs.

Methods

Medical records of all patients (n = 139) treated for NWRTs over a 12-year period (2008.01–2019.10) at a single center were reviewed retrospectively.

Results

The histopathological groups of NWRTs included malignant rhabdoid tumor of the kidney (MRTK) (n: 30, 21.6%), renal cell cancer (RCC) (n: 26,18.7%), clear cell sarcoma of the kidney (CCSK) (n: 24,17.3%), congenital mesoblastic nephroma (CMN) (n: 21,15.1%), cystic nephroma (CN) (n: 16,11.5%), metanephric tumors (n: 12, 8.6%), renal angiomyoliporma (RAML) (n: 3, 2.2%), renal primitive neuroectodermal tumor (n: 2, 1.4%), renal hemangioma (n: 2, 1.4%), inflammatory myofibroblastic tumor (n: 2, 1.4%), ossifying renal tumor of infancy (ORTI) (n: 1, 0.7%). The distribution of all malignant NWRTs, including MRTK, CCSK, RCC and PNET, according to stage was as follows: stages I (n = 26), II (n = 16), III (n = 29), and IV (n = 11). The summary table shows the treatment offered to children with NWRTs. A total of 123 children were followed up for an average of 42 months. Sixteen children were lost to follow-up. Tumor-free survival was observed in 94 children. One patient who suffered from RCC is currently receiving targeted therapy and survives with the tumor. Twenty-eight children (22.8%) died.

Conclusions

Pediatric NWRTs comprise 19.1% of all renal tumors in our single center. Most NWRTs can readily be distinguished using a range of immunohistochemical markers. Molecular genetic profiling has allowed much progress in the understanding of this group of tumors, making diagnosis and classification less difficult. The mainstay treatment of malignant NWRTs, including MRTK, CCSK, RCC and PNET, is comprehensive treatment. The mainstay treatment of benign NWRTs, including RAML, CN, ORTI, CMN, metanephric tumors, and renal hemangioma, is surgical resection alone and when the tumor diameter is smaller than 7 cm and the tumor locates in one pole, NSS can be performed.

Health disparities among tennessee pediatric renal tumor patients

BACKGROUND/PURPOSE

Wilms tumor (WT) poses a cancer health disparity to black children globally, which has not been evaluated thoroughly for other pediatric renal cancers. We aimed to characterize health disparities among Tennessee children treated for any renal cancer.

METHODS

The Tennessee Cancer Registry (TCR) was queried for patients ≤18 years having any renal cancer (n = 160). To clarify treatment and outcomes, we performed a retrospective cohort study of pediatric renal cancer patients in our institutional cancer registry (ICR; n = 121). Diagnoses in both registries included WT, Sarcoma/Other, and Renal Cell Carcinoma. Wilcoxon/Pearson, Kaplan-Meier, and logistic regression were completed.

RESULTS

In both registries, WT comprised the most common renal cancer and youngest median age. Sarcoma was intermediate in frequency and age, and RCC was least common, having the oldest age (p < 0.001). In the TCR, black patients comprised 26% of all patients, presented more commonly with distant disease than white patients (37% v. 16%; p = 0.021), and showed worse overall survival (73% v. 89%; p = 0.018), while the ICR showed similar survival between race groups (92% v. 93%, p = 0.868). Sarcoma and metastases were independent predictors of death in both registries (p ≤ 0.002).

CONCLUSIONS

Black children in Tennessee presented with more advanced disease and experienced worse survival when combining all renal cancer types, particularly RCC and Sarcoma. When treated at a comprehensive pediatric cancer center, these survival disparities appear diminished.

TYPE OF STUDY

Prognostic study.

LEVEL OF EVIDENCE

Level II (retrospective cohort).