1. Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
2. Cancer Epidemiology Research Program, Catalan Institute of Oncology, Institut d'Investigació Biomédica de Bellvitge, L’Hospitalet de Llobregat, Catalonia, Spain
3. Centros de Investigación Biomédica en Red, Epidemiología y Salud Pública, Madrid, Spain
4. Clinics, Paris, France, GlaxoSmithKline, Wavre, Belgium
5. GlaxoSmithKline, Wavre, Belgium