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Childhood Cancer
Chapter II
Rates and Risk Factors |
About 87 percent of all pediatric kidney cancers are Wilms' tumor. Wilms' tumor is rare in persons over age 15 and behaves very differently from adult kidney cancers.
Incidence Rates
The incidence of kidney cancers among children in NJ and in the US was 0.8 per 100,000 (Table 1a). Wilms' tumor accounted for almost all of these cases. The incidence among girls in NJ and the US (0.9 per 100,000) was higher than among boys (0.6 per 100,000 in NJ; 0.8 per 100,000 in the US). In NJ, the incidence rate of kidney cancers was higher among white children than among black children, whereas in the US, the incidence rate was higher among black children than among white children (Table 1b). The reason for this difference is not known.
Incidence and Mortality Trends
Figure 10 presents incidence and mortality trends for childhood kidney cancers. Incidence rates for NJ and the US were very stable at about 0.9 per 100,000. Mortality rates for kidney cancers were very low and declined slightly to nearly zero over the period.
Wilms' Tumor: Demographic Patterns and Survival
In New Jersey, Wilms' tumor is more common in black children than in white children and in girls than in boys. Incidence of Wilms' tumor is highest in the first two years of life and declines thereafter. The five-year survival rate is 89 percent for children with this disease.7
Risk Factors
Genetic
Wilm's tumor can be hereditary, but familial Wilms' tumor comprises only 1.0 to 2.4 percent of all cases. The genes responsible for the transmission have not been identified.7 Patients with certain genetic syndromes have a predisposition to Wilms' tumor: Beckwith-Weidmann syndrome, Perlman syndrome, and Drash syndrome.7, 25
Parental Occupation
Some studies have suggested increased risk of renal cancers in children of fathers or mothers exposed to certain substances through their occupations. Most of these studies did not have sufficient numbers of subjects or specific enough data on exposures to be definitive. The paternal exposures investigated were hydrocarbons, lead, solvents and pesticides and the maternal exposures were aromatic amino hydrocarbons (electronics, clothing manufacturing, dental assistants), aromatic azo compounds (cosmetic sales, clothing manufacturing, hairdressers, laboratory workers) and pesticides.23, 24
