Objective: To analyze retrospectively the quantity and activation status of the tumor infiltrating cytotoxic lymphocytes in breast cancer and the draining lymph nodes, and its relation to the clinical pathological significance.
Methods: Seventy-four breast cancer samples with their corresponding axillary lymph nodes were histologically typed and staged. Cytotxic lymphocytes were analyzed by immunohistochemistry with the monoclonal antibodies against CD8, CD56, granzyme B and perforin.
Results: The number of infiltrating CD8(+) T cells in the cancerous interstitial tissue were much higher than that in the tumor parenchyma. Compared with the metastatic tumor samples, the CD8(+) T cells were more intensive in the primary tumors (35.7 +/- 16.0 vs. 23.7 +/- 9.6). The tumor infiltrating CD8(+) T cells of patients with 5 years survivals were more than that of the dead cases in this follow-up series death (32.9 +/- 14.1 vs. 20.1 +/- 9.9). There was no significant difference of activated tumor infiltrating cytotoxic T cell analyzed by using the activation marker granzyme B(+) and there was also no significant correlation between the intensity of CD8(+), CD56(+) cells and the clinicopathological stages. However, percentages of the activated cytotoxic lymphocytes in Stage I groups were significantly higher than those in stage III and IV. Moreover, the number of perforin(+) cells was significantly less than that of granzyme B(+) cells, particularly in the cancerous tissue, indicating a dysfunctional status of tumor infiltrating cytotoxic lymphocytes.
Conclusions: Activated cytotoxic lymphocytes may play a significant role against the tumor progression and is associated with a favorable prognosis to some extent. However, a putative dysfunctional status of cytotoxic lymphocytes at tumor site may compromise the host immunity against cancer.