The hematologic parameters in metastatic castration-resistant prostate cancer patients treated with abiraterone acetate.

Abstract

308 Background: The aim of this study is to evaluate the prognostic implications of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at baseline and after 4 and 12 weeks of treatment with abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC). Methods: We retrospectively evaluated 102 mCRPC treated with abiraterone either pre- or post-chemotherapy between November 2012 and October 2017 in three institutions. We calculated NLR and PLR at baseline and at 4 and 12 weeks after initiation of abiraterone, and we evaluated prostate-specific antigen (PSA) response every 4 weeks. Fifty patients (49%) were treated with abiraterone post-docetaxel, and 52 patients (51%) received abiraterone pre-chemotherapy. Based on receiver operating characteristic analysis, patients were stratified as low NLR ( < 3.1) or high NLR (≥ 3.1), and low PLR ( < 163) or high PLR (≥ 163). The cutoff for anemia was < 12g/dL. Results: Median follow-up times for patients overall and for those who survived were 24.0 months (range, 0.3 – 54.9 months) and 25.5 months (range, 2.8 – 54.9 months), respectively. The median time of abiraterone treatment was 8.1 months (range, 2.4 – 40.1 months). The median overall survival (OS) was 20.8 months (interquartile range: 17.3–24.4). In univariate analysis, NLR, PLR, PSA response, and low hemoglobin (Hgb) were found significantly predictive of OS and progression-free survival (PFS). In multivariate analysis, declines in NLR and PSA of ≥ 90% emerged as significant independent predictors of OS and PFS. High-NLR patients who remained high or who returned to low NLR after 4 and 12 weeks showed significantly worse OS than patients with low baseline NLR. Patients with baseline Hgb > 12 g/dL had significantly longer median OS compared with patients with Hgb ≤ 12 g/dL; however, the significance of Hgb was lost at 12 weeks. Conclusions: NLR and PSA response to abiraterone was a significant predictor of OS and PFS in mCRPC patients treated with abiraterone delivered either pre- or post-chemotherapy. Furthermore, persistent increase in NLR during abiraterone has prognostic value for OS in patients with mCRPC.