Background: Immune responses play an important role in the development of breast cancer. Trastuzumab can activate antibody-dependent cellular cytotoxicity (ADCC) in human epidermal growth factor receptor-2 (HER-2)-positive breast cancer. Many studies have demonstrated that inflammatory markers, such as the neutrophil-to-lymphocyte ratio (NLR) and absolute lymphocyte count (ALC), are associated with prognosis in breast cancer. The aim of this study was to explore whether preoperative NLR, ALC or the absolute neutrophil count (ANC) is associated with prognosis in HER-2-positive breast cancer patients who received adjuvant trastuzumab. Patients and methods: Three hundred sixty-seven female patients with HER-2-positive invasive breast cancer who were treated with one-year adjuvant trastuzumab were analysed in this retrospective study. Preoperative haematological parameters, clinicopathological data and survival data were obtained. The cut-off points for ALC, ANC and NLR were based on the median values. Disease-free survival (DFS) and Overall survival (OS) were analysed by the Kaplan-Meier method. Multivariable Cox regression was used to determine the independent prognostic significance of ALC, ANC and NLR. Results: Survival analysis revealed that the 3-year DFS in patients with high ALC was 89.0%, which was significantly worse than 95.0% in patients with low ALC (p=0.014). Kaplan-Meier analysis also showed that patients with low NLR had a poorer 3-year DFS than patients with high NLR (89.7% vs 94.0%, respectively; p=0.047). Multivariate analysis showed that ALC was an independent prognostic factor for DFS (HR=2.723; 95% CI=1.211-6.122; p=0.015). Neither ANC, ALC nor NLR could predict OS independently. Conclusion: In HER-2-positive breast cancer patients who were treated with adjuvant trastuzumab, a high ALC is significantly associated with a poor DFS.
Keywords: HER-2 positive; absolute lymphocyte count; breast cancer; neutrophil-to-lymphocyte ratio; trastuzumab.