Prognostic role of radiological splenic vessel involvement in patients with resectable pancreatic ductal adenocarcinoma of the body and tail: A retrospective analysis based on a large population.

BACKGROUND: Tumors located in the pancreatic body or tail are more likely to invade splenic vessels; however, splenic artery (SpA) or vein (SpV) involvement is not included in the criteria for resectability. We aimed to analyze the prognostic role of radiological splenic vessel involvement in patients with resectable pancreatic ductal adenocarcinoma (PDAC) of the body and tail. METHODS: Patients with resetable PDAC were retrospectively reviewed and analyzed. SpA and SpV involvement were graded as clear, abutment and encasement. Multivariate Cox and logistic regression analyses were used to identify prognostic factors for overall survival (OS) and risk factors for early recurrence, respectively. RESULTS: Of the 234 patients, 94 patients had radiologic SpA invasion, including abutment in 47 patients and encasement in 47 patients, while 123 patients had radiological SpV invasion, including abutment in 69 patients and encasement in 54 patients. Patients with SpA or SpV encasement showed a significantly worse OS and recurrence-free survival than those with SpA or SpV clear (P < 0.001, respectively). In multivariate analysis, both SpA and SpV encasement were independently associated with poor OS (SpA: hazard ratio [HR] 1.89, P = 0.010; SpV: HR 2.01, P = 0.001) and early recurrence (SpA: odds ratio [OR] 4.98, P < 0.001; SpV: OR 3.71, P = 0.002). CONCLUSION: Radiological SpA or SpV encasement independently decreases OS, and is associated with early recurrence of resectable PDAC of the body/tail.