1. Department of Registration, Cancer Registry of Norway , Oslo, Norway
2. Department of Cardiothoracic Surgery, Rikshospitalet, Oslo University Hospital , Oslo, Norway
3. Section of Oncology, Vestre Viken Hospital Trust , Drammen, Norway
4. Institute of Clinical Medicine, University of Oslo , Oslo, Norway
5. Department of Pulmology, Rikshospitalet, Oslo University Hospital , Oslo, Norway
6. Department of Pathology, St. Olavs Hospital, Trondheim University Hospital , Trondheim, Norway
7. Department of Oncology, Oslo University Hospital , Oslo, Norway