[1] Univ Calif San Diego, Canc Prevent & Control Program, Dept 0901, La Jolla, CA 92093 USA
[2] Univ Calif San Diego, Canc Prevent & Control Program, Dept Family & Prevent Med, La Jolla, CA 92093 USA
[3] Univ Calif San Diego, Canc Prevent & Control Program, Womens Hlth Eating & Living Study, La Jolla, CA 92093 USA
[4] Kaiser Permanente No Calif, Kaiser Fdn, Res Inst, Div Res, Oakland, CA USA
[5] Univ Calif Davis, Dept Epidemiol & Prevent Med, Davis, CA 95616 USA
[6] Stanford Univ, Dept Med, Stanford Ctr Res Dis Prevent, Palo Alto, CA 94304 USA