[1] Canc Prevent Inst Calif, Fremont, CA 94538 USA
[2] Stanford Univ, Sch Med, Dept Hlth Res & Policy & Med, Div Epidemiol, Stanford, CA 94305 USA
[3] NCI, Div Canc Epidemiol & Genet, NIH, Rockville, MD USA
[4] Univ Iowa, Dept Epidemiol, Iowa City, IA USA
[5] City Hope Natl Med Ctr, Dept Pathol, Duarte, CA 91010 USA
[6] Univ Calif Los Angeles, Dept Epidemiol, Los Angeles, CA USA