- Patient or guardian consent must be obtained on all patients according to local Institutional and/or University Human Experimentation Committee requirements. Children > 8 years old whose parent or guardian has signed consent on their behalf may also sign assent if desired. It will be the responsibility of the local participating investigators to obtain the necessary local clearance, and to indicate in writing to the NCIC CTG Study Coordinator that such clearance has been obtained, before the trial can commence in that centre.