VAIL, CO USA (UroToday.com) - Background: Factors associated with rates of progression from non-metastatic to metastatic castration resistant prostate cancer (CRPC) have been described.[1, 2]
We used this information to identify patients at high risk for progression from non-metastatic to metastatic disease (MD) for entry into the IMpact of Abiraterone Acetate in Prostate Specific AntiGEN (IMAAGEN) trial.
Objective: To report the high rate of unsuspected metastases in asymptomatic patients with CRPC, leading to screen failure.
Methods: From April 2011-July 2013, patients were screened for entry into the IMAAGEN trial. Key entry criteria included having CRPC as defined by a rising PSA and a serum T <50 ng/dL and a PSA ≥10 ng/mL or PSA doubling time (PSADT) ≤10 months. Primary endpoint of IMAAGEN was proportion of subjects achieving a ≥ 50% reduction in PSA by 6 cycles of treatment. During screening, patients who met entry criteria based on laboratory results underwent imaging studies to screen for local disease progression or MD.
Results: 298 patients were screened. 167 (56%) patients screen failed. 77 patients had MD, which represents 37% of 208 patients who, by lab results, were eligible for and underwent imaging studies. We will report on the relationship of unsuspected MD to PSA/PSADT entry criteria.
Conclusions: A high rate of unsuspected asymptomatic MD was found in this high-risk CRPC patient population (PSA ≥10 ng/mL or PSADT ≤10months). Our findings build upon other reported data on MD discovered during screening for non-metastatic CRPC trials. These findings suggest the need to prospectively define risk factors for development of MD in CRPC to assure timely identification, especially in light of new treatment options.
Study funded by Janssen Services, LLC.
- Smith MR,Kabbinavar F,Saad F et al. Natural History of Rising Serum Prostate-Specific Antigen in Men with Castrate Nonmetastatic Prostate Cancer. J Clin Oncol 2005;23:2918-2925.
- Smith MR,Cook R,Lee K et al. Disease and Host Characteristics as Predictors of Time to First Bone Metastasis and Death in Men with Progressive Castration-Resistant Nonmetastatic Prostate Cancer.Cancer 2011;117:2077-85
- Yu EY,Miller K,Nelson J et al. Detection of previously unidentified metastatic disease as a leading cause of screening failure in a phase III trial of zibotentan versus placebo in patients with nonmetastatic, castration resistant prostate cancer. J Urol 2012;188:103-109.
Presented by E. David Crawford, Jannell R. DePalantino, Philip W. Kantoff, Neal Shore, Willie Underwood, Vijay Reddy, Jim Wang, Suneel Mundle, Zane Yang, Tracy McGowan, and Charles J. Ryan at the 24th International Prostate Cancer Update - February 19 - 22, 2014 - Cascade Conference Center - Vail, Colorado USA
University of Colorado Cancer Center, Aurora, CO
Janssen Services, LLC., Horsham, PA
Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
Carolina Urologic Research Center, Myrtle Beach, SC
Roswell Park Cancer Institute, Buffalo, NY
Janssen Research & Development, LLC, Raritan, NJ
Helen Diller Family Comprehensive Cancer Center, University of California- San Francisco, San Francisco, CA