[1] German Canc Res Ctr, Div Canc Epidemiol, Neuenheimer Feld 280, D-69120 Heidelberg, Germany
[2] Heidelberg Univ, Med Fac Heidelberg, Heidelberg, Germany
[3] German Canc Res Ctr, Div Biostat, Heidelberg, Germany
[4] Univ Med Ctr Hamburg Eppendorf, Univ Canc Ctr Hamburg, Hamburg, Germany