PURPOSE: We investigated imaging practice patterns in men with nonmetastatic (M0) castration resistant prostate cancer.
MATERIALS AND METHODS: We analyzed data on 247 patients with documented M0 CRPC from the SEARCH database. Patients were selected regardless of primary treatment modality and bone scan was negative after a castration resistant prostate cancer diagnosis. Cox models were used to test associations of time to a second imaging test with several demographic and clinical factors.
RESULTS: During a median followup of 29.0 months (IQR 12.9-43.5) after a post-castration resistant prostate cancer bone scan was negative 190 patients (77%) underwent a second imaging test. On univariable analysis patients with higher prostate specific antigen (HR 1.13, p = 0.016), shorter prostate specific antigen doubling time (HR 0.79, p < 0.001) and faster prostate specific antigen (HR 1.01, p < 0.001) were more likely to undergo a second imaging test. Treatment center was also a significant predictor of a second imaging test (p = 0.010). No other factor was a significant predictor. Results were similar on multivariable analysis. It was estimated that approximately 20% of men with a prostate specific antigen doubling time of less than 3 months did not undergo an imaging test in the first year after a post-castration resistant prostate cancer negative bone scan. However, 50% of patients with prostate specific antigen doubling time 15 months or greater underwent a second imaging test in the first year.
CONCLUSIONS: Clinicians use some known predictors of positive imaging tests to determine which patients with M0 castration resistant prostate cancer undergo a second imaging test . However, there may be under imaging in those at high risk and over imaging in those at low risk. Further studies are needed to identify risk factors for metastasis and form clear imaging guidelines in patients with M0 castration resistant prostate cancer.
Sourbeer KN, Howard LE, Moreira DM, Amarasekara HS, Chow LD, Cockrell DC, Hanyok BT, Pratson CL, Kane CJ, Terris MK, Aronson WJ, Cooperberg MR, Amling CL, Hernandez RK, Freedland SJ. Are you the author?
Urology Section, Veterans Affairs Medical Center, Duke University School of Medicine, Durham, North Carolina; Duke Prostate Center, Division of Urology, Department of Surgery, Duke University School of Medicine, Durham, North Carolina; Department of Biostatistics, Duke University School of Medicine, Durham, North Carolina; Department of Pathology, Duke University School of Medicine, Durham, North Carolina; Department of Urology, Mayo Clinic, Rochester, Minnesota; Urology Department, University of California-San Diego Health System, San Diego; Urology Section, Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles; Department of Urology, University of California-Los Angeles School of Medicine, Los Angeles; Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco; Center for Observational Research, Amgen, Inc., Thousand Oaks, California; Sections of Urology, Veterans Affairs Medical Center and Medical College of Georgia, Augusta, Georgia; Division of Urology, Oregon Health Sciences University (CLA), Portland, Oregon.
Reference: J Urol. 2014 Nov 13. pii: S0022-5347(14)04858-7.