Neutrophil count is associated with survival in localized prostate cancer

Abstract

BACKGROUND: Increasing evidence suggests a close relationship between systemic inflammation and cancer development and progression. The neutrophil to lymphocyte ratio (NLR) has been shown to be an independent prognostic indicator in various advanced and localized cancers. We investigated the influence of markers of systemic inflammation such as leucocyte counts and metabolic co-morbidities on overall survival (OS) after radiotherapy for localized prostate cancer. METHODS: We conducted a retrospective study of patients with localized prostate cancer treated with definitive external beam radiotherapy or brachytherapy. Univariate and multivariate cox proportional hazards models were used to investigate the influence of the following factors on OS: age, neutrophil and lymphocyte counts, neutrophil-to-lymphocyte ratio (NLR), Cancer of the Prostate Risk Assessment (CAPRA) score as well as comorbidities associated with inflammation such as cardiac history, diabetes and use of a statin. A stepwise selection of variable based on the Akaike information criterion (AIC) was used for multivariate analysis. RESULTS: In total, 1772 pts were included; blood count data was available for 950 pts. Median age was 68 years (44-87). Actuarial 5 years OS and biochemical recurrence-free survival (BRFS) for the 1772 patients were 93% and 95%, respectively, with a median follow-up of 44 months (1-156). On univariate analysis, neutrophil count (p = 0.04), cardiac history (p = 0.008), age (p = 0.001) and CAPRA (p = 0.0002) were associated with OS. Lymphocytes, NLR and comorbidities other than cardiac history were not associated with mortality. On multivariate analysis, neutrophil count (HR = 1.18, 95 % CI: 1.017-1.37, p = 0.028), age (HR = 1.06, 95 % CI: 1.01-1.1, p = 0.008) and CAPRA (HR = 1.16, 95 % CI: 1.03-1.31, p = 0.015) were independent predictors of OS. CONCLUSION: Neutrophil count, as a possible marker of systemic inflammation, appear to be an independent prognostic factor for overall mortality in localized prostate cancer. A validation cohort is needed to corroborate these results.