Comparative analysis of CD4 and CD8 lymphocytes - evidences for different distribution in primary and secondary liver tumors.

INTRODUCTION The impact of tumor cells on tumor-infiltrating lymphocytes (TILs) in cancer development is not yet clarified. Our study analyzed the distribution and prognostic value of CD4+ and CD8+ T lymphocytes in hepatocellular carcinoma (HCC) and liver metastases (LM). MATERIAL AND METHODS Archival tissue specimens of 35 HCC and 39 LM patients were immunohistochemically processed. The number of intratumoral (IT) and peritumoral (PT) CD4+ and CD8+ T cells was quantitatively analyzed. RESULTS We noted large variances of T lymphocyte subpopulations. Similar number of CD4+ and CD8+ lym-phocytes was present in HCC, whereas in LM the number of CD8+ cells was approximately two times higher than CD4+ lymphocytes. A significant prevalence of T cells in PT over IT areas was observed. The prognostic value was demonstrated only for PT CD8+ lymphocytes in LM, their reduced number being associated with shorter survival. CONCLUSIONS The differences between proportions of T lymphocytes within tumor and its environment might be explained by proapoptotic effect of cancer cells on TILs.