[1] Univ Michigan, Sch Med, Dept Pathol, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sch Med, Dept Internal Med, Ann Arbor, MI 48109 USA
[3] Univ Philippines, Philippine Gen Hosp, Dept Med, Clin Epidemiol Unit, Manila, Philippines
[4] Hosp Llobregat, Inst Catala Oncol, Serv Epidemiol & Registre Canc, E-08907 Barcelona, Spain
[5] Int Agcy Res Canc, F-69372 Lyon 08, France