There is a growing body of literature highlighting the prognostic use of pre-operatively comparing certain white blood cell differentials, namely neutrophils and lymphocytes, with outcomes in many different types of solid tumour cancers. It has been postulated that a raised neutrophil to lymphocyte ratio (NLR) may reflect a greater tumour burden on the patient, and therefore lead to poorer outcomes. There is some evidence that a raised pre-operative NLR may help to predict poorer outcomes following surgery for breast cancer.
This observational retrospective proof of concept study aims to assess the association between pre-operative NLR and breast cancer outcomes over a three year period of follow-up from a cohort of 147 patients. The results of this study revealed that the cohort of patients with a raised pre-operative NLR was associated with a clinically significant increased rate of local recurrence of their breast cancer following surgery with curative intent (with or without adjuvant chemotherapy and radiotherapy) compared to those that had a low or normal NLR (20.4% ± 4.9% vs 5.1% ± 4.9% respectively, CI 95%; p=0.004). In relation to intra-operative sentinel lymph node biopsy, the analysis also showed that the incidence of a raised pre-operative NLR was not related to whether there was nodal involvement or not at the time of surgery (33% vs 33%, p=1). This suggests that a raised pre-operative NLR may be an independent prognostic indicator for breast cancer outcomes.
This study provides a template for a prospective observational study which is needed to corroborate this result and to account for confounding factors such as concomitant chronic disease. Additionally, a larger cohort sample size with a follow-up of five years is necessary to assess the relationship between pre-operative NLR and mortality due to the latter's relatively low incidence in breast cancer. However, this study further supports that consideration of the pre-operatively calculated NLR may provide an early prognostic indicator for breast cancer outcomes and warrants further investigation.
Citation Format: Williams GJ, Huws AM, Holt SDH, Sharaiha YM. Neutrophil lymphocyte ratio and breast cancer: A future prognostic indicator for outcome after surgery?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-01-07.