UroToday.com - In the online version of Urology, Dr. Kaplan and associates at Fox Chase Cancer Center report on residual prostate cancer (CaP) after radiotherapy (RT) in men undergoing radical cystoprostatectomy for bladder indications.
Between 1990 and 2007, 21 patients had a cystoprostatectomy for cancer (19), radiation cystitis (1) and rectal cancer (1). A total of 17 had external beam RT and 4 had brachytherapy. Eighty-three percent had low to intermediate risk localized disease. Median age at diagnosis of CaP was 71 years and the initial PSA was 9.0ng/ml. The median time between RT and cystoprostatectomy was 60 months. Definition of biochemical recurrence was the Phoenix definition of PSA nadir + 2.
Before cystoprostatectomy the median PSA was 0.8ng/ml. Of the 18 patients who had post-RT data available to evaluate biochemical failure, 16 (89%) met the Phoenix definition for biochemical freedom from disease. Yet residual CaP was found in 52% at cystoprostatectomy. In patients considered free from disease according to the Phoenix definition, 50% (8 of 16) had residual CaP. Median PSA in patients with residual CaP at the time of cystoprostatectomy was 1.0ng/ml, not statistically different from the 0.6ng/ml in those without evidence of disease. Also, the time interval between RT and cystoprostatectomy did not differ in those with and without residual CaP. Gleason score was upgraded in 4 of 7 patients who had both pre- and post- cystoprostatectomy data.
Limitations to this study include the small population and retrospective nature. It does, however raise the issue of complete tumor kill in patients having RT and the ability for the Phoenix definition of failure to accurately predict this histologic finding.
