1 Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
2 Department of Upper Gastrointestinal Surgery, South Hospital, Stockholm, Sweden.
3 Department of Surgery and Cancer, Imperial College, London, UK.
4 Division of Family Medicine and Primary Care, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
5 University of Newcastle, Australia.
6 School of Cancer and Pharmaceutical Sciences, King's College London, and Guy's and St Thomas' NHS Foundation Trust, UK.