Presence of tumor deposits is an indicator of poor prognosis in patients with pancreatic ductal adenocarcinoma.

Tumor deposits (TDs) are associated with poor prognosis in several malignancies and have been incorporated into the tumor-node-metastasis (TNM) staging system for colorectal cancer. This study aims to explore the significance of TDs in pancreatic ductal adenocarcinoma (PDAC). All patients who underwent pancreatectomy with a curative intent for PDAC were retrospectively enrolled. Patients were categorized into 2 groups according to the status of TDs: the positive group, in which TDs were present, and the negative group, in which TDs were absent. The prognostic significance of TDs was evaluated. In addition, a modified staging system was developed by incorporating TDs into the eighth edition of the TNM staging system. One hundred nine (17.8%) patients had TDs. Patients with TDs demonstrated significantly lower 5-year overall survival (OS) and recurrence-free survival (RFS) rates than those without TDs (OS: 9.1% 21.5%, =0.001; RFS: 6.1% 16.7%, <0.001). Even after matching, patients with TDs still had significantly worse OS and RFS than those without TDs. In the multivariate analysis, the presence of TDs was an independent prognostic factor in patients with PDAC. The survival of patients with TDs was similar to that of patients with N2 stage disease. The modified staging system had a greater Harrell's C-index than the TNM staging system, which indicates better performance in predicting survival. The presence of TDs was an independent prognostic factor for PDAC. Categorizing patients with TDs into N2 stage improved the accuracy of the TNM staging system in predicting prognosis.