for the DCOG-LATER Study Group IMPORTANCE Survivors of childhood cancer (CCSs) face risk of developing subsequent tumors. Solid benign tumors may be cancer precursors; benign tumors and cancers may share etiologic factors. However, comprehensive data on the risk for solid benign tumors are lacking. OBJECTIVE To quantify the incidence of and treatment-related risk factors for histologically confirmed solid nonskin benign tumors among CCSs. DESIGN, SETTING, AND PARTICIPANTS This record linkage study involves the Dutch Childhood Oncology Group-Long-Term Effects After Childhood Cancer (DCOG-LATER) cohort of 6165 individuals diagnosed with childhood cancer at younger than 18 years from January 1, 1963, through December 31, 2001, in 7 Dutch pediatric centers and who survived at least 5 years after the diagnosis. Study groups eligible for record linkage from 1990 onward included 5843 CCSs (94.8%) and 883 siblings. Benign tumors were identified from the population-based Dutch histopathology and cytopathology registry (PALGA). Follow-up was completed on May