21P Characteristics of the lymphocytic infiltrate in breast cancer

The impact of lymphocytic infiltrate is well demonstrated in breast cancers. The study of the NK cell population is poorly documented with discordant results. This study aims to evaluate the degree of lymphocytic infiltrate and CD56 + NK cell infiltrate as well as their correlations with clinicopathological factors and with survival. This is a retrospective study of breast cancer cases collected in Habib Bourguiba Hospital in Sfax. CD56 expression was assessed by a immunohistochemical method. There were 119 cases of breast carcinoma. Quantification of TIL's was performed in 113 patients. The tumors were classified as low grade in 56 cases (49.5%), medium grade in 17 cases (15.04%) and high grade in 41 cases (35.4%). The predominantly lymphocytic tumors were observed in 23 cases (20.3%). An elevated level of CD56 + cells was observed in 24 cases (21.4%). In univariate analysis, TIL's were associated with the metastatic stage (p = 0.03) without correlation with the other factors. NK-TIL's were associated with young age, high SBR grade, negative hormone receptors, high Ki-67 proliferation index, and molecular class (more common in non-luminal tumors). OS at 5 years was 97% in TIL's high-grade tumor level versus 52% in the low grade tumor group (p <0.001). The OS at 5 years was 88% for tumors with a high level of CD 56+ cells versus 72.5% for tumors with a low level of CD56 + cells (p = 0.042). Systematic measurement of TIL's for breast cancer is recommended. A high subpopulation of CD56 + cells correlates with better survival.