Contribution of Immunoscore to Survival Prediction in Pancreatic Ductal Adenocarcinoma

Abstract

Background/aim: The presence of tumor-infiltrating lymphocytes (TILs) has been demonstrated as a prognostic factor in colorectal cancer after surgical resection of malignancy, but knowledge on their role in pancreatic cancer is lacking. The Immunoscore (IS) assesses TILs at the core of the tumor (CT) and invasive margin (IM) and is being evaluated as a new concept in tumor immunity. The aim of this study was to evaluate the relationship between IS and prognosis in PDAC.

Patients and methods: The IS was analyzed by immunohistochemistry using surgical tissue blocks from 131 patients with pancreatic ductal adenocarcinoma (PDAC) who underwent surgery to investigate the relationship between immune cell infiltration into the tumor and prognosis in PDAC.

Results: A high IS in both CT and IM of the tumor was significantly associated with prolonged overall survival (OS) (p<0.01) and relapse-free survival (RFS) (p<0.01). In multivariate logistic regression models adjusted for clinical pathology data, IS predicted survival and recurrence (p<0.01 and p<0.01, respectively). Moreover, in patients who received preoperative chemotherapy, a high IS was statistically significantly associated with longer OS and RFS (p<0.01 and p<0.01, respectively).

Conclusion: The immunohistochemically assessed IS might be a useful prognostic marker for patients with PDAC who underwent primary tumor resection.

Keywords: PD-L1; Pancreatic ductal adenocarcinoma; immunoscore; prognostic indicator; tumor microenvironment.