The aim of this study is to validate both retrospectively and prospectively a newly proposed scoring system for perineural and vascular invasion in pancreatic ductal cancer and correlate it with disease free survival, early recurrence, site of recurrence, overall survival and neoadjuvant treatment.

Perineural invasion (PNI) is defined as the presence of cancer cells along nerves and/or within the epineural, perineural and endoneural spaces of the neuronal sheath.Clinically, PNI is associated with increased tumor recurrence, poor survival after pancreatectomy and pain, an invalidating symptom that may impair quality of life. Pancreatic ductal adenocarcinoma has one of the highest incidences of PNI (70-100%) among all types of cancer, which correlates with a poor prognosis and decreased survival. PNI is a still not uniformly characterized or quantified event, usually it is described only dichotomously ("present" or "absent"), despite some efforts to use a more detailed scoring system. However, these scores are not specifically developed for pancreatic surgical specimen. Vascular invasion (VI), which is assumed to be associated with a more aggressive tumor biology and dissemination, lacks a specific scoring system as well. The primary aim of this study is to validate both retrospectively and prospectively a novel PNI and VI scoring system aimed at a more detailed stratification of perineural invasion, together with an accompanying scoring system for vascular invasion, and correlated them with disease free survival (DFS).

Inclusion Criteria:

• Patients older than 18 years
• Patients undergoing all types of pancreatic resection (pancreatoduodenectomy, left pancreatectomy, total pancreatectomy, both laparotomic and laparoscopic).
• Proven pancreatic ductal adenocarcinoma (cytology or biopsy).
• Patients that received neoadjuvant therapy (CT +/- RT) can be included.
• Patients able to sign the informed consent.

Exclusion Criteria:

• Age < 18 years.
• Patients with other ongoing oncological diseases.

Patients with a confirmed pancreatic ductal adenocarcinoma at the histological examination after surgery with resective purposes.