Neutrophil-to-Lymphocyte ratio (NLR) is an independent prognostic marker for feline mammary carcinomas.

Abstract

Blood leukocyte counts and respective derived ratios have been described as potential prognostic markers in several tumours in veterinary oncology. This study aimed to evaluate peripheral blood leukocyte subpopulations and NLR as prognostic factors for Feline Mammary Carcinomas (FMC). Medical records from cats diagnosed with FMC between 2017-2019 were reviewed. Cats were included if fully staged, classified as WHO stage I to III, and submitted to mastectomy. Cats were excluded if they had evidence of other diseases. Forty-nine cats were included. The study endpoints were disease-free interval (DFI) and tumour-specific survival (TSS). The median DFI and TSS were 389\u2009days and 528\u2009days respectively. In the univariate analysis, higher values of total white blood cell count (WBC), neutrophil count (NEU) and NLR were identified as significant prognostic factors for both endpoints (P\u2009<\u20090.05). On the multivariate analysis, NLR remained an independent prognostic factor for TSS (P\xa0=\xa00.024). In the ROC curve analysis, the estimated cut-off for WBC was 8.49 x 109 /L (DFI and TSS); for NEU was 4.62 x 109 /L (DFI) and 6.65 x 109 /L (TSS) and for NLR was 2.46. These cut-offs were significant prognostic factors for DFI and TSS (P\u2009<\u20090.05). NLR cut-off remained an independent prognostic factor for both DFI (P\xa0=\xa00.032) and TSS (P\xa0=\xa00.043) in the multivariable analysis. Our results suggest that NLR, NEU and WBC can be important non-invasive presurgical prognostic markers, and that NLR is an independent prognostic marker for FMC. Prospective studies are warranted to validate its clinical use. This article is protected by copyright. All rights reserved.