Neutrophil:lymphocyte ratio as a simple and novel biomarker for prediction of locoregional recurrence after chemoradiotherapy for squamous cell carcinoma of the anus

Abstract

The neutrophil: lymphocyte ratio (NLR) is a prognostic marker in several malignancies. This study assessed whether it can be used as a predictor of loco-regional recurrence after chemoradiotherapy for anal squamous cell carcinoma (SCC). Patients treated with curative intent between 1 January 2004 and 31 December 2011 were identified. Pretreatment blood tests and radiological staging were available from multidisciplinary meeting records. The NLR was calculated from pretreatment blood tests. The relationship between the NLR and clinicopathological parameters was analysed. Modified receiver-operating characteristics curves were constructed to determine the cut-off NLR to dichotomise the data for survival analyses. The measured cut-off was 4.75. Ninety-two patients were identified. Pretreatment T-stages were T1 (n=7), T2 (n=36), T3 (n=35) and T4 (n=14) and pretreatment N stages were N0 (n=62) and N+ disease (n=30). The NLR was significantly higher in N+ disease (P=0.014) and in patients who developed recurrence (P=0.003). On multivariate analysis, the NLR maintained its significance, with a hazard ratio (HR) of 1.38 (95% CI=1.195-1.594) (P<0.0001). An elevated NLR was associated with worse overall (P<0.0001) and cancer-specific (P<0.0001) survival. Multivariate Cox regression analysis demonstrated that an elevated NLR was prognostic for overall survival (HR=6.381, 95% CI=1.742-23.372, P=0.005) and for cancer-specific survival (HR=10.613, 95% CI=1.968-57.241, P=0.006). Pretreatment NLR may be a simple biomarker for predicting disease recurrence and overall and cancer-specific survival after potentially curative chemo-radiotherapy for SCC of the anus.