International assessment and validation of the prognostic role of lymph node ratio in patients with resected pancreatic head ductal adenocarcinoma

Gaëtan-Romain Joliat, Ismail Labgaa, Jesse Sulzer, Dionisios Vrochides, Alessandro Zerbi, Gennaro Nappo, Julie Perinel, Mustapha Adham, Stijn van Roessel, Marc G. Besselink, J. Sven D. Mieog, Jesse V. Groen, Nicolas Demartines, Markus Schäfer