1 Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. Electronic address: e.a.dijkstra@umcg.nl.
2 Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
3 Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, The Netherlands.
4 Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Radiation Oncology, Leiden University Medical Center, Leiden, The Netherlands.
5 Department of Surgery, Karolinska University Hospital, Stockholm, Sweden.
6 Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.
7 Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
8 Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.