Prognostic effect of stromal lymphocyte infiltration in thymic carcinoma

Abstract

BACKGROUND: The purpose of this study was to clarify the relationship between the tumor infiltrating lymphocytes and clinical outcome in patients with thymic carcinoma.

METHODS: Tissue specimens from 32 patients who underwent surgical resection for thymic carcinoma were immunohistochemically analyzed for CD4, CD8 and CD20 expression.

RESULTS: Tumor-infiltrating lymphocytes were generally more abundant in the stroma. The patients with low CD4+ lymphocytes (p=0.037) and low CD20+ lymphocytes (p=0.045) within tumor stroma showed poor survival. Furthermore, concurrent low levels of CD4+ and CD20+ (p=0.014), CD8+ and CD20+ (p=0.025), and, CD4+, CD8+, and CD20+ (p=0.025) in tumor stroma were significantly associated with poor prognosis when compared to the others group.

CONCLUSION: Our results indicate that infiltrating CD4+, CD8+, and CD20+ lymphocytes in cancer stroma may cooperate to suppress cancer progression and their presence together appear to be prognostic factor in thymic carcinoma.