Impact of pre-treatment neutrophil-lymphocyte ratio on outcomes in men receiving radical external beam radiotherapy for localised prostate cancer.

Abstract

151 Background: There is a shortage of novel biomarkers in clinical use for the diagnosis and management of prostate cancer. The neutrophil-lymphocyte ratio (NLR) is a potentially useful biomarker derived from a standard full blood count from peripheral blood sampling, which is readily available and relatively inexpensive. An elevated NLR has been shown to be a poor prognostic biomarker in many advanced solid cancers, including prostate cancer (PC); however, data on NLR in non-metastatic PC have been inconsistent. The objective of this study was to evaluate baseline NLR as an independent predictor of outcome following radical radiotherapy for non-metastatic PC. Methods: Data from 477 consecutive PC patients treated with radical EBRT between 2005 and 2009 in Northern Ireland were reviewed. Outcomes included biochemical progression-free survival (bPFS; Phoenix definiton), prostate cancer-specific survival (PCSS) and overall survival (OS). A two-tailed Mann-Whitney test (significance level 5%) was used to compare NLR in each group. Results: Complete data for 409 patients were available. At a median follow-up of 75 months (range 12 – 138), 74 men (16%) had biochemical failure (BF), 12 men (3%) had died of PC, and 65 men (14%) had died of all causes. Actuarial 5-year bPFS was 91%, PCSS was 97% and OS was 89%. Median NLR was 2.42 in both the BF and non-BF groups (p = 0.78), 2.21 and 2.42 in men who died from PC and those who did not (p = 0.39) and 2.40 and 2.42 in those men who died from all causes and those men who remained alive (p = 0.83). See Table for additional data. Conclusions: In this cohort with medium- to long-term follow-up, NLR was not predictive for bPFS, PCSS or OS. Multivariate analysis of this cohort is planned. Additional prognostic biomarkers are required in PC. [Table: see text]