[1] Emory Univ, Rollins Sch Publ Hlth, Dept Epidemiol, Atlanta, GA 30322 USA
[2] Emory Univ, Dept Biostat & Bioinformat, Rollins Sch Publ Hlth, Winship Canc Inst, Atlanta, GA 30322 USA
[3] Emory Univ, Sch Med, Dept Surg, Atlanta, GA 30322 USA
[4] Emory Univ, Sch Med, Dept Hematol & Med Oncol, Winship Canc Inst, Atlanta, GA USA
[5] Emory Univ, Sch Med, Dept Radiat Oncol, Atlanta, GA USA
[6] Emory Univ, Sch Med, Dept Internal Med, Div Digest Dis, Atlanta, GA USA