1. Department of Thoracic Surgery, Second University of Naples, Naples, Italy
2. Department of Thoracic Surgery, Medical University of Lublin, Lublin, Poland
3. Thoracic Surgery Unit, Department of Surgery, University of Perugia, Perugia, Italy
4. Department of Medical Statistics, Second University of Naples, Naples, Italy
5. Thoracic Surgery Unit, Department of Thoracic Surgery, Istituto Oncologico del Mediterraneo “IOM”, Catania, Italy