Development of a Nomogram for Predicting Severe Neutropenia Associated With Docetaxel-Based Chemotherapy in Patients With Castration-Resistant Prostate Cancer.

Abstract Background Neutropeniais a major adverse event of docetaxel-based chemotherapy. The present study was undertaken to evaluate the incidence of neutropeniaand to develop a nomogramfor predicting Grade 4 neutropeniaduring the first cycle of docetaxel-based chemotherapy in patients with castration-resistant prostate cancer (CRPC). Patients and Methods This study included 112 patients with CRPC treated with docetaxel-based systemic chemotherapy. We evaluated the incidence and risk factors for Grade 4 neutropeniain the first cycle of chemotherapy. Results Sixty-two of 112 patients (55.4%) developed Grade 4 neutropeniain the first cycle of docetaxel-based chemotherapy. There were significant differences in age, baseline white blood cell count, and baseline neutrophil count between patients with non-Grade 4 neutropeniaand those with Grade 4 neutropeniain univariate analyses. The serum prostate-specific antigen level, hemoglobin level, creatinine, albumin, Eastern Cooperative Oncology Group performance status, metastatic sites, extent of disease, and history of external beam radiotherapyto the prostate were not significantly different between the 2 groups. Multivariate logistic regression analysis showed that age (odds ratio [OR], 1.08; P = .019) and baseline neutrophil counts (OR, 0.79; P = .045) were significant independent risk factors for severe neutropenia. A nomogramand a calibration plot on the basis of these results were developed from a multivariate logistic regression analysis to predict the probability of Grade 4 neutropenia. Conclusion Age and baseline neutrophil counts were significant independent risk factors for Grade 4 neutropenia. The nomogramto predict it provides useful information for the management of patients with CRPC treated with docetaxelchemotherapy.