Molecular Analysis in Pediatric Renal Tumors

Abstract

Although the incidence of pediatric cancers has increased steadily over the last 35 years, the incidence of pediatric kidney tumors has not changed in the same time period. Pediatric kidney tumors represent approximately 5% of cancer diagnoses among children and adolescents below the age of 20 (http://seer.cancer.gov/, Fig. 10.1). However, the incidence is age dependent so that malignant kidney tumors account for 9.7% of the total among children younger than 5 years of age, 5.4% in children 5–9 years of age, 1.1% in children 10–14 years of age, and 0.6% in adolescents 15–19 years of age. Of the approximately 550 children and adolescents diagnosed with renal tumors each year, approximately 500 are Wilms tumor (WT). The remaining includes variants of renal cell carcinoma (RCC), clear cell sarcoma of the kidney, rhabdoid tumor of the kidney, congenital mesoblastic nephroma (CMN), as well as other rare tumors (Histopathology 54:516–528, 2009). Because the incidence of WT and other pediatric renal tumors is very much agedependent, age at diagnosis perhaps provides the best clinical clue to the diagnosis. For example, some tumors occur almost entirely in infancy (e.g., CMN) whereas others occur almost exclusively in adolescence (e.g., RCC). Indeed, RCC accounts for about 5% of pediatric renal tumors but comprises the majority of tumors by late adolescence (Cancer Incidence and Survival among Children and Adolescents: United States SEER Program 1975–1995, National Cancer Institute, SEER Program, 1999) (Fig. 10.2).KeywordsKidneyRenalTumorMolecularGeneticDiagnosisChildhoodPediatric