1. Department of Public Health Policy, School of Public Health, University of West Attica, 115 21 Athens, Greece
2. Laboratory of Hygiene, Social & Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece
3. Oncology Unit, 3rd Department of Medicine, “Sotiria” Hospital for Diseases of the Chest, National and Kapodistrian University of Athens, 115 27 Athens, Greece
4. Dana-Farber Cancer Institute, Boston, MA 02215, USA