Efficacy and toxicity of abiraterone and docetaxel in octogenarians with metastatic castration-resistant prostate cancer Raya Leibowitz-Amit a, 1 , Arnoud J. Templeton a, 1 , Shabbir M. Alibhai b , Jennifer J. Knox a , Srikala S. Sridhar a , Ian F. Tannock a , Anthony M. Joshua a, ⁎ a Department of Medical Oncology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada b Department of Medicine, University Health Network, Toronto, ON M5G 2M9, Canada ARTICLE INFO ABSTRACT Article history: Received 20 May 2014 Received in revised form 24 August 2014 Accepted 19 September 2014 Available online 7 October 2014 Objective: To assess the efficacy and toxicity of abiraterone and docetaxel in men with metastatic castration-resistant prostate cancer (mCRPC) of age >80 compared to younger men. Methods: Retrospective chart review of 116 men treated with abiraterone and 378 men treated with docetaxel at Princess Margaret Cancer Centre. Categorical outcome measures including PSA response rate (PSA-RR) and incidence of toxic side-effects were compared using Fisher's exact test. Overall survival (OS) and biochemical progression free survival (bPFS) were analyzed using the Kaplan–Meier method and log-rank tests. Results: Thirty-four (29%) and 50 (13%) of the men treated with abiraterone or docetaxel, respectively, were octogenarians. For abiraterone there were no significant differences in PSA-RR (42% vs. 39%), bPFS (4.7 vs. 4.4 months) or OS (14.0 vs 20.7 months) between octogenarians and younger men, respectively. Toxicity was mild with no significant differences between age groups. For men treated with docetaxel PSA-RR and OS did not differ between age groups (40% vs. 45% and 12.0 vs. 14.1 months, respectively). However, rates of febrile neutropenia were 16% and 7% for octogenarians and younger men, respectively (p = 0.048). This difference was observed despite greater use of lower dose intensity and weekly docetaxel in the elderly cohort, with 20% of them receiving lower than standard dose during their first cycle compared to 7% of younger men (p = 0.004). Conclusions: Treatment outcome on abiraterone and docetaxel did not differ in patients over and under the age of 80, but febrile neutropenia was more common in octogenarians treated with docetaxel despite lower dose intensity. © 2014 Elsevier Ltd. All rights reserved. Keywords: Abiraterone Docetaxel mCRPC Octogenarians Toxicity Efficacy Prostate cancer JOURNAL OF GERIATRIC ONCOLOGY 6 (2015) 23 – 28 Abbreviations: bPFS, biochemical progression free survival; CI, confidence interval; ECOG PS, Eastern cooperative group performance status; EPR, electronic patient record; mCRPC, metastatic castration resistant prostate cancer; OS, overall survival; PM, Princess Margaret; PSA, Prostate specific antigen; PSA-RR, PSA response rate. ⁎ Corresponding author at: Department of Medical Oncology, Princess Margaret Cancer Centre, 610 University Avenue, Toronto, ON M5G 2M9, Canada. Tel.: + 1 416 946 4501; fax: + 1 416 946 6546. E-mail address: anthony.joshua@uhn.ca (A.M. Joshua). 1 Equal contribution. http://dx.doi.org/10.1016/j.jgo.2014.09.183 1879-4068/© 2014 Elsevier Ltd. All rights reserved. Available online at www.sciencedirect.com ScienceDirect