1 1Epidemiology, University of Texas School of Public Health, Houston, USA 2Preventive Medicine, Keck School of Medicine of USC, Los Angeles, USA 3Biostatistics and Genetic Epidemiology, Keck School of Medicine of USC, Los Angeles, USA 4Gynecologic Oncology, Duke Cancer Center, Durham, USA 5Epidemiology, Memorial Sloan Kettering Cancer Center, New York, USA 6Epidemiology, University of Cambridge, Cambridge, United Kingdom.