[1] Univ Calif Los Angeles, Sch Publ Hlth, Los Angeles, CA 90024 USA
[2] Univ Calif Los Angeles, Jonsson Comprehens Canc Ctr, Div Canc Prevent & Control Res, Los Angeles, CA 90024 USA
[3] Natl Surg Adjuvant Breast & Bowel Project NSABP, Ctr Biostat, Pittsburgh, PA USA
[4] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Biostat, Pittsburgh, PA 15261 USA
[5] Natl Surg Adjuvant Breast & Bowel Project NSABP, Operat Ctr, Pittsburgh, PA USA
[6] Allegheny Gen Hosp, Dept Human Oncol, Pittsburgh, PA 15212 USA
[7] Univ Calif Los Angeles, David Geffen Sch Med, UCLA Dept Surg, Los Angeles, CA 90024 USA
[8] W Los Angeles Vet Affairs Med Ctr, Dept Surg, Los Angeles, CA 90073 USA