High infiltration of CD3+ and CD8+ T-Lymphocytes correlates with improved survival in pancreatic cancer

Abstract

Background: Tumor microenvironment plays a vital role in the progression of malignancies. Infiltrating lymphocytes may influence prognosis in pancreatic cancer after resection. We have previously established an algorithm to quantify immune cell infiltration in the tumor stroma. We now aimed to establish an immunoscore for pancreatic cancer and correlate immune cell infiltration of B-, T-Lymphocytes, and neutrophils with clinical outcome. Methods: 30 patients operated in 2014 were included. Immunhistochemical staining of CD3, CD8, CD20, and CD66b was performed. The previously established algorithm was used for quantification. Results: Median survival was 17.5 months with an average follow-up of 16.6 months. High infiltration of CD3+ T-lymphocytes correlated significantly with favorable overall- (p=0.046) and disease free survival (p=0.001). High infiltration of CD8+ T-lymphocytes showed a clear correlation with better overall survival (p=0.006). CD20 and CD66b did not correlate with clinical outcome. Combination of high infiltration of CD3 and CD8 showed a highly significant correlation with improved both overall- (p=0.031) and disease free survival (p=0.004). Conclusion: High infiltration of CD3+ and CD8+ T-lymphocytes correlates with favorable prognosis. The future use of immunoscoring systems may help to predict prognosis after resection.