1. Cancer Epidemiology and Prevention Research Unit, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London , London, UK
2. Department of Hygiene and Epidemiology, University of Ioannina School of Medicine , Ioannina, Greece
3. Cancer Epidemiology Unit, Oxford Population Health, University of Oxford , Oxford, UK
4. MRC Integrative Epidemiology Unit, University of Bristol , Bristol, UK