Neutrophil-lymphocyte ratio as prognostic factor in metastatic breast cancer

Background: The role of the neutrophil to lymphocyte ratio (NLR) as a prognostic factor in metastatic breast cancer (MBC) is still controversial. Our aim was to analyze its importance in survival prediction in recurrent MBC.

Methods: A retrospective cohort study including 351 recurrent MBC patients was performed. Clinical and pathological attributes were retrieved from patients’ medical files and their importance in the overall survival were evaluated using the Cox univariate and multivariate proportional hazard models. Collinear variables were filtered out to test the final regression model. A confidence interval of 95% was used to select significant variables and the Wald test was used to infer the best NLR cutoff value to discriminate into low and high categories.

Results: The median overall survival time was 12.3 months. In univariate analyses, the variables ER expression, PR expression, previously treated with adjuvant chemo, NLR, PLR (platelet-lymphocyte ratio), age at diagnosis and the main metastatic site (bone/lymph node, visceral or central nervous system) variables were significant to determine the hazards. After filtering the collinear variables, the final model was tested with 6 variables based on 295 patients and the NLR, the hormone receptor (ER or PR) status and the age at diagnosis were considered significant (Table 1). The best NLR value to discriminate against patients was 4.42 (Wald test= 46.0) and there were 222 patients categorized as low and 83 as high NLR category. The median overall survival time was 19.5 and 4.4 months in NLR-low and NLR-high groups, respectively (p< 0.0001).

Conclusions: NLR is an independent prognostic factor in recurrent MBC patients.

Corresponding author: Renan Caetano Braga Pimenta (e-mail: renancbp@yahoo.com.br).