Prognostic Value of Natural Killer Cells Besides Tumor-Infiltrating Lymphocytes in Breast Cancer Tissues

Abstract

BackgroundEach subgroup of immune cells has a different prognostic role in breast cancer; however, the prognostic impact of tumor-infiltrating natural killer cells (TINKs) is still not well established. Our aim was to assess the prognostic impact of natural killer (NK) cells in breast carcinomas. Materials and MethodsNK cells infiltration were assessed by immunohistochemistry (IHC). Statistical analyses were performed to evaluate the correlation of NK cells with clinical-pathological features and outcome. ResultsCD56 IHC was realized in 126 patients. NK cells infiltration showed significant and positive association with tumor high Scarff-Bloom-Richardson (SBR) grade. NK cells were significantly associated with HER2-positive breast cancer and triple-negative breast cancer subtypes. Analyses showed significant and inverse correlation with progesterone and estrogen receptors expression status. High NK cells were significantly related to high Ki-67 labeling index. Our data showed that high NK cells infiltrate was significantly associated with tumor-infiltrating lymphocytes in breast cancer tissues.At a median follow-up of 5.5 years, high CD56 expression (≥ 5 cells/10 high power field) was associated significantly with a good overall survival and with good disease-free survival. ConclusionIn this study, we assessed the important prognostic role of TINKs in breast carcinomas, which seems to be evident despite its association with aggressive pathological features. Thus evaluation of NK cells can be standardized and integrated in daily routine.