Prognostic value of intratumoral CD8+ T lymphocyte in extrahepatic bile duct carcinoma as essential immune response

Background and Objectives Tumor‐infiltrating lymphocytes form an important aspect of the host defense against an expanding neoplasm. CD8+ T cells have been identified as a prognostic factor in several cancers. Here, we investigate that the influence of CD8+ T cells on extrahepatic bile duct carcinoma (EBDC) patient survival. Methods CD8+ T cell immunoreactivity in 58 surgically resected EBDC specimens was investigated. The relationship between CD8+ T cell immunoreactivity and clinical and histopathologic features was analyzed. Results Thirty‐two tumors (55%) possessed intratumoral CD8+ T cells. The degree of intratumoral CD8+ T cell immunoreactivity demonstrated a significant relationship to lower numbers of lymph node metastasis, reduced venous invasion, decreased perineural invasion, and better pTNM staging. Intratumoral CD8+ T cells were also associated with increased patient survival. Multivariate analysis indicated that the presence of intratumoral CD8+ T cells was an independent prognostic factors. Conclusions The infiltration of a cancer cell nest by CD8+ T cells is a reliable marker predicting increased survival of patients with EBDC. J. Surg. Oncol. 2003;84:224–228. © 2003 Wiley‐Liss, Inc.