[1] NCI, Pediat Oncol Branch, Bethesda, MD 20892 USA
[2] George Washington Univ, Dept Psychol, Washington, DC 20052 USA
[3] Frederick Natl Lab Canc Res, Leidos Biomed Res Inc, Clin Res Directorate, Clin Monitoring Res Program, Ft Detrick, MD 21702 USA
[4] Univ N Carolina, Sch Hlth & Human Sci, Dept Publ Hlth Educ, Greensboro, NC 27412 USA