Lymph node ratio, perineural invasion and R1 resection as independent prognostic factors in pancreatic adenocarcinoma: A retrospective cohort study

1. Martino, M.D.
2. Ielpo, B.
3. DE NOVA, J.L.M.
4. Muñoz, E.A.
5. Santamaria, C.
6. Diago, V.
7. Martín-Pérez, E.