Neutrophil-to-lymphocyte ratio as a predictor of response to abiraterone acetate in metastatic castration-resistant prostate cancer
Anne-Sophie Valiquette1, Giacomo Rebez2, Louis Lacombe3, Yves Fradet3, Frédéric Pouliot3, Carmen Mir4, Jose Rubio Briones4, Maria José Juan4, Paul Toren3.
1Division of Urology, Université de Montréal, Montreal, QC, Canada; 2Department of Urology, University of Trieste, Trieste, Italy; 3Division of Urology, Université Laval (CHUQ), Quebec, QC, Canada; 4Department of Urology, Instituto Valenciano de Oncologia, Valencia, Spain
Introduction: Prior work from the landmark COU302 study suggested that neutrophil-to-lymphocyte ratio (NLR) may act as a predictive biomarker of abiraterone acetate (AA) response in first-line castration-resistant prostate cancer (CRPC) patients. We assess the role of NLR as a prognostic marker for patients receiving AA as first-line treatment for CRPC.
Methods: Clinical data on all patients treated with AA for first-line CRPC at two institutions from 2013–2020 were included in this retrospective study. Clinical information was collected by chart review. Kaplan-Meier survival was compared using a log-rank test. Cox proportional hazards model assessed whether NLR group independently predicted overall survival (OS), cancer-specific survival (CSS), and length of abiraterone treatment, with adjustment for baseline variables. Based on prior work, NLR was dichotomized using a cutoff of 2.5
Results: A total of 170 patients who received AA for first-line CRPC treatment were included. The median followup was 25.7 months. Forty-seven of 60 deaths were related to prostate cancer. The median time on abiraterone was 17 months. Thirty-five patients received chemotherapy as second-line therapy. On Kaplan-Meier analysis, OS (hazard ratio [HR] 2.24, 95% confidence interval [CI] 1.27–3.96, p=0.005) and CSS (HR 1.98, 95% CI 1.07–3.67, p=0.03) were shorter in the high NLR group, but this was not significant on multivariable analysis. Moreover, NLR group did not predict the length of abiraterone treatment, with the presence of >10 metastases and baseline prostate-specific antigen >15 ng/ml significant predictors of treatment response on univariable and multivariable analyses. However, on multivariable analysis, NLR >2.5 was the most significant risk factor (HR 2.15, 95% CI 0.98–4.70, p=0.05) for receipt of chemotherapy after adjustment for the presence of >10 metastases and above-normal lactate dehydrogenase.
Conclusions: Our real-world data from first-line CRPC patients do not suggest NLR is an independent biomarker of response to abiraterone, though an elevated NLR >2.5 did suggest a higher likelihood of receipt of second-line chemotherapy
