Real-world treatment patterns in men with castration-resistant prostate cancer receiving docetaxel
Background: Docetaxel has been a standard of care for castration-resistant prostate cancer (CRPC) in the United States since 2004, yet little has been reported on its patterns of use in routine practice. To help understand these patterns, a retrospective study was conducted and is reported here.
Methods: Medical records from 394 patients treated in the United States were reviewed. Data were collected by 48 physicians from oncology (patient N=344) and 8 physicians from urology (patient N=50) practices. Inclusion criteria were: CRPC diagnosed between 2004 and 2010; received docetaxel; discontinued docetaxel due to rising prostate-specific antigen (PSA), progression of bone lesions, or progression of nodal or visceral metastases. Data were collected from physicians using an internet-based case report form. We evaluated patient demographics, characteristics of the docetaxel regimen, and other treatments used until docetaxel discontinuation.
Results: Patients had a mean [±SD] age of 66.5 [8.9] years, the majority (63%) were white, and geographic dispersion was similar to the US population. The majority of patients initiated docetaxel between 2008 and 2010. After CRPC diagnosis, 8% of patients had initiated another cancer-directed therapy before starting docetaxel. Most (78.9%) patients initiated docetaxel with prednisone, while 18.5% initiated docetaxel alone and 2.6% initiated with other medications. Half of patients initiated docetaxel within 1 month after CRPC diagnosis, while 25% started ?6 months later. Other non-chemotherapy treatments used with docetaxel were hormonal therapy (22.8%), radiotherapy (17.3%), and surgery (4.1%). Most patients (75%) received ?4 docetaxel cycles, half received ?6 cycles, 25% received ?8 cycles and 10% received ?10 cycles. Increased tumor mass, with/without new bone lesions or rising PSA, was the most common reason for docetaxel discontinuation (74% of patients).
Conclusions: Concordant with guidelines, docetaxel and prednisone was the preferred first-line chemotherapy regimen in CRPC patients reviewed for this study. However, one quarter of patients did not initiate docetaxel until ?6 months after CRPC diagnosis and total exposure varied considerably, with only 10% receiving ?10 cycles. Future studies are needed to describe specific reasons explaining timing of docetaxel initiation and duration of exposure in some CRPC patients.