Prostate cancer detected on repeat biopsies have more favorable tumor characteristics but similar recurrence rates

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Mar 17 2006

Prostate cancer (CaP) detected on repeat biopsy may reflect smaller volume tumors and less aggressive biological and clinical disease.

Dr. Lopez-Corona and associates at Memorial-Sloan Kettering Cancer Center examined this question in over 1000 patients and found more favorable pathologic tumor characteristics, but similar rates of biochemical recurrence.

Their report appears in the March 2006 issue of the Journal of Urology.

Clinical and pathologic data were collected on 1,357 patients treated with radical prostatectomy by one surgeon (Dr. Scardino) between 1983 and 2001. Clinical stage T1-T2 disease was present in 94% of the cohort. CaP was detected at first biopsy in 1,042 patients (77%), at second biopsy in 227 (17%), at third biopsy in 59(4%) and at fourth or later biopsy in 29(2%).

Men diagnosed at initial biopsy were more likely to have smaller prostates, and abnormal digital rectal examinations. No difference was identified in the number of men diagnosed with a biopsy Gleason sum of 7 or higher regardless at which biopsy the cancer was detected. Of the men diagnosed at initial biopsy, 61% had organ confined CaP compared to 75% of 315 patients diagnosed on two or greater biopsies. Furthermore, extracapsular extension, seminal vesicle invasion, frequency of poorly differentiated tumors and lymph node metastases were higher in men diagnosed on initial biopsy.

Median cancer volume was significantly greater in men diagnosed at first biopsy (2.02cc vs. 1.13cc, respectively). Prostates greater than 50cc in size were more likely to meet the investigators definition of indolent tumors than glands smaller than 50cc in size.

Despite the pathologic differences, the progression-free probability at 5 years was similar (mean 78.7%) regardless of how many biopsies were necessary to detect the CaP.

By Christopher P. Evans, MD