OBJECTIVETo assess and compare the prognostic role of tumor-infiltrating T lymphocytes in stage 1-3 breast cancer.

METHODSParaffin sections were retrospectively collected from 130 cases of stage 1-3 breast cancer patients who received surgery between January 2000 and December 2002 in General Hospital of the People's Liberation Army. Immunohistochemistry was used to assess the density of tumor-infiltrating lymphocytes(TILs) that were positive of CD4 and CD8. These variables were evaluated for their association with histopathologic features along with overall survival(OS) , distant disease-free survival(DDFS) and disease-free survival(DFS) .

RESULTSIntraepithelial CD4+lymphocytes infiltration was an independent prognostic factor for DFS(HR=0.248, 95%CI=0.113-0.543, P=0.000) , DDFS(HR=0.361, 95%CI=0.157-0.830, P=0.017) , and OS(HR=0.297, 95%CI=0.119-0.741, P=0.009) in multifactor COX regression model. In hormone receptor negative group, mesenchymal CD8+lymphocytes and intraepithelial CD8+lymphocytes were independent prognostic factors for OS(HR=0.286, 95%CI=0.101-0.807, P=0.018) and DDFS(HR=0.293, 95%CI=0.104-0.825, P=0.020) , respectively. In hormone receptor positive group, mesenchymal CD8+lymphocytes and intraepithelial CD8+lymphocytes were independent prognostic factors for OS(HR=4.854, 95%CI=1.435-16.415, P=0.011) and DDFS(HR=10.493, 95%CI=1.226-89.795, P=0.032) respectively. Further analysis found that OS of hormone receptor positive patients with lower mesenchymal CD8+TILs was significantly proved by adjuvant endocrine therapy.

CONCLUSIONSIn the current investigation, intraepithelial CD4+TILs demonstrated independent prognostic significance for survival. CD8+TILs were associated with better survival in hormone receptor negative patients but associated with worse survival in hormone receptor positive patients. The long-term clinical effects of adjuvant endocrine therapy is related with density of mesenchymal CD8+TILs and in turn affected prognostic value of mesenchymal CD8+TILs.