OUTLINE: This is a case-control, multicenter study. Case patients are stratified. Stratum 1 comprises patients for whom there is an appropriate Pediatric Oncology Group (POG) frontline therapeutic protocol that has not yet been submitted to, disapproved by, or approved by the Institutional Review Board (IRB). Stratum 2 comprises patients for whom there is an appropriate POG frontline therapeutic protocol that has been approved by the IRB. Physicians complete an IRB submission form for their patients on stratum 1. Patients/parents on stratum 2 who refused enrollment and their primary physicians complete questionnaires that address reasons for nonenrollment. Control patients/parents who consented to enrollment complete questionnaires that address reasons for enrollment. Demographic information, including the size of the treating institution and the annual number of patients enrolled onto its protocols, is collected. Additional demographic information regarding the patient and his or her family is collected.