OBJECTIVETo assess the prognostic value of CD20(+) tumor-infiltrating lymphocytes (TILs) in early-stage breast cancer.

METHODSParaffin sections were collected from 130 cases of stage I-III breast cancer undergoing surgery between January, 2000 and December, 2002 in our hospital. Immunohistochemistry was used to analyze mesenchymal CD20(+) TILs infiltration in the tumor and evaluate its association with the density of CD4(+) and CD8(+) TILs. The association of CD20(+) TILs was evaluated with the histopathologic features, overall survival (OS), distant disease-free survival (DDFS), and disease-free survival (DFS) of the patients.

RESULTSAggregations of CD20(+) lymphocytes were observed in 37.69% (49/130) of the cases. CD3(+) T cells were found to aggregate around CD20(+) B cell aggregations to form lymphoid follicle-like structures. The aggregations of CD20(+) TILs were positively correlated with the densities of mesenchymal CD8+ and CD4(+) TILs. Overall, CD20(+) TIL aggregations were not significantly correlated with the outcomes of the patients, but multivariate COX regressions suggested that CD20(+) TIL aggregations were positively correlated with DDFS (HR=0.251, 95% CI=0.071-0.894, P=0.033) and OS (HR=0.325, 95% CI=0.103-1.028, P=0.056) in hormone receptor-negative patients but not in the positive patients. Further analysis suggested that post-operative adjuvant endocrine therapy significantly improved the OS of patients positive for hormone receptors without CD20(+) TIL aggregations (P=0.001).

CONCLUSIONThe long-term therapeutic effects of adjuvant endocrine therapy are correlated with CD20(+) TIL aggregations to affect prognostic value of CD20(+) TIL aggregations in early-stage breast cancer patients.