1 Department of Surgery, Leiden University Medical Center, Leiden, Netherlands.
2 Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, Netherlands.
3 Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, Netherlands.
4 Department of Radiation Oncology, Leiden University Medical Center, Leiden, Netherlands; Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, Netherlands.
5 Department of Biomedical Datasciences, Leiden University Medical Center, Leiden, Netherlands.
6 Department of Surgery, Karolinska University Hospital, Stockholm, Sweden.
7 Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
8 Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, Netherlands. Electronic address: g.a.p.hospers@umcg.nl.