Pediatric Oncology Education Materials

Wilms tumor is also called nephroblastoma.

The fourth most common form of childhood cancer and the most common primary renal tumor in children (6% of all childhood cancer).

Table : Summary of Wilms Epidemiology

Annual incidence (<16 years)	7 per million children under 16
Proportion of pediatric cancers	6%
Age affected	Mostly <5 years old 0.16% occur in neonates 50% are less than 3 years old 90% are less than 7 years old Extremely rare over the age of 15 Sporadic cases with unilateral tumors present at an older age (median 36 months) than familial synchronous bilateral Wilms tumor (median age 26 months).
Proportion of patients with various anomalies	Musculoskeletal: 2.9% Genitourinary: 4.4%
Peak incidence	3-4 years Median age at diagnosis is 3.5 years
Gender bias	Generally female predominance for both unilateral and bilateral tumors. The male to female ratio is 0.92 for unilateral tumors. The male to female ratio is 0.6 for bilateral tumors. In South East Asia excess of cases in males.