[1] Leiden Univ, Dept Surg, Med Ctr, Leiden, Netherlands
[2] Netherlands Comprehens Canc Org IKNL, Dept Res, Utrecht, Netherlands
[3] Belgian Canc Registry, Brussels, Belgium
[4] Lund Univ, Dept Surg, Lund, Sweden
[5] Karolinska Inst, Div Surg, Dept Clin Sci Intervent & Technol CLINTEC, Stockholm, Sweden
[6] Karolinska Univ Hosp, Ctr Digest Dis, Sect Esophagogastr Surg, Stockholm, Sweden
[7] Univ Oslo, Inst Clin Med, Oslo, Norway
[8] Oslo Univ Hosp, Dept Gastroenterol & Pediat Surg, Oslo, Norway
[9] Oslo Univ Hosp, Dept Oncol, Oslo, Norway
[10] Aarhus Univ Hosp, Dept Surg, Aarhus, Denmark
[11] Natl Qual Improvement Programme RKKP, Danish Natl Registries, Aarhus, Denmark
[12] Royal Marsden NHS Fdn Trust, Dept Surg, London, England
[13] Leiden Univ, Med Ctr, Dept Med Oncol, Leiden, Netherlands