Patient risk factors and pegfilgrastim use in cabazitaxel-treated prostate cancer pateints in an academic setting.

Abstract

224 Background: Cabazitaxel can offer a survival advantage in patients (pts) with metastatic castration resistant prostate cancer (mCRPC). Febrile neutropenia (FN) has emerged as a serious complication, with a rate of 8% in the TROPIC trial (de Bono, Lancet 2010). Prophylaxis with pegfilgrastim (P) can decrease the risk of FN, although predictors of FN continue to evolve. We performed an analysis on the effect of prophylactic P use on FN and the impact of certain risk factors on FN rates. Methods: We conducted a retrospective analysis of mCRPC patients treated with cabazitaxel from June 2010 to August 2013 at Dana-Farber Cancer Institute. Patient clinical and treatment variables were extracted. Fisher’s exact test was used to evaluate the association between potential risk factors and FN. Results: A total of 89 patients were treated at our institution and included in this analysis. All patients received at least one dose of cabazitaxel and received a mean of four cycles. Five pts (5.6%) developed FN; 3 out of 70 (4.3%) receiving P and 2 out of 19 (10.5%) not receiving P (p=0.3). Of the 24 patients that started cabazitaxel at a reduced dose, none developed FN. No toxic death was reported. Among several risk factors including P use, age older than 65, pre-existing neutropenia, prior chemotherapy, pre-existing infection, poor performance status, liver and renal dysfunction, and recent surgery, only a prior history of palliative radiation had a significant association with FN (p=.002). Conclusions: The rate of FN in a large academic practice is similar to what was reported in the TROPIC trial. Prior radiation may be a risk factor for FN in cabazitaxel-treated mCRPC patients. Other factors that may help better predict the risk of FN in different groups of patients receiving cabazitaxel must be identified.