Role of CD4- and CD8-Positive T Cells in Breast Cancer Progression and Outcome: A Pilot Study of 47 Cases in Central India Region

Abstract

Immune response plays an important role in cancer progression. In humans, the study of the inflammatory infiltrate in malignancies, mainly T lymphocytes, has been a subject of great interest. The study was conducted to correlate CD4- and CD8-positive lymphocyte expression with other prognostic factors in invasive breast cancer, such as clinical stage, histological grade, tumour size and clinical course. It was a retrospective cross-sectional study. In this study, 47 cases of breast carcinoma which were diagnosed at least 12 months back from the initiating point of study were included. The immunohistochemical expression of CD4 and CD8 in lymphocytes infiltrating the intratumoural, adjacent or distant stroma sites was studied and correlated with other prognostic factors. Less occurrence of adverse outcome was found with the presence of CD8+ T cells anywhere in the vicinity of tumour (only 27%, 7 out of 26 cases) as compared to the group in which both CD4+ and CD8+ T cells were absent where adverse outcome occurred in 78% (7 of 9 cases, p = 0.007). High histological grade was found to be associated with negative CD8+ T cells staining in 21 out of 30 cases with grade III tumours at distant stroma site (p = 0.026). Presence of CD8 cells at intratumoural site had reduced disease-free survival (DFS) (8 months) as compared to their absence at the same site (DFS = 31 months, log rank p = 0.001). CD4 and CD8 staining did not correlate with clinical staging (p > 0.05). Infiltration around the primary tumour by CD8+ T cells in carcinoma breast is a sign of good prognosis, while their absence indicates more adverse outcomes. On the other hand, intratumoural infiltration is associated with rapid advancement of disease. CD4+ cells did not correlate well with prognosis.