Role of CD8 Cytotoxic T Lymphocytes in Hepatocellular Carcinoma: An Immunohistochemical Study

Abstract
Background: Hepatocellular Carcinoma (HCC) is the most common primary malignancy of the liver in adults accounting for 85%-90% of liver tumors. It represents the sixth most common malignancy and the fourth leading cause of cancer-related death worldwide. There is an important role of CD8+ tumor infiltrating lymphocytes in host immune defense against tumour progression. Immunotherapy, with modern pharmacologic developments, is a new direction in cancer therapy and therefore immunobiology of hepatocar-cinogenesis is under investigation.
Aim of Study: Study expression of CD8 in Hepatocellular carcinoma and its correlation with clinicopathological param-eters and explore its effect on HCC prognosis.
Material and Methods: This study included 112 hepato-cellular carcinoma cases obtained from the archival material of Pathology Department, National Liver Institute, Menoufia University, between 2010 and 2017. All cases were stained for CD8 antibody. Survival data were available for all HCC cases.
Results: CD8 was expressed in 110 HCC cases (98.2%). There was a statistical significant association between high CD8 percentage and non-cirrhotic adjacent liver (p=0.035). On the other hand, there was a significant association between high CD8 percentage and large tumor size (<5cm) (p=0.015). There was no statistically significant association between CD8 expression and overall survival or recurrence.
Conclusion: We concluded that high CD8 might serve as bad prognostic parameter in HCC as it is associated with non-cirrhotic liver and large tumor size but it doesn't affect HCC overall survival or recurrence.