PROSTATE CANCER DIAGNOSIS USING A SATURATION NEEDLE BIOPSY TECHNIQUE AFTER PREVIOUS NEGATIVE SEXTANT BIOPSIES

Abstract

We hypothesized that markedly increasing the number of cores obtained during prostate needle biopsy may improve the cancer detection rate in men with persistent indications for repeat biopsy. We performed saturation ultrasound guided transrectal prostate needle biopsy in 224 men under anesthesia in an outpatient surgical setting in whom previous negative biopsies had been performed in the office. The mean number of previous sextant biopsy sessions plus or minus standard deviation before saturation biopsy was 1.8 (range 1 to 7). A mean of 23 saturation biopsy cores (range 14 to 45) were distributed throughout the whole prostate, including the peripheral, medial and anterior regions. Indications for repeat biopsy were persistent elevated serum prostate specific antigen (PSA) in 108 cases, persistent elevated PSA and abnormal rectal examination in 27, persistent abnormal rectal examination in 4, high grade prostatic intraepithelial neoplasia in the previous biopsy in 64 and atypia in the previous biopsy in 21. Cancer was detected in 77 of 224 patients (34%). The number of previous negative sextant biopsies was not predictive of subsequent cancer detection by saturation biopsy. Median PSA was 8.7 ng./ml. and median PSA velocity was 0.63 ng./ml. yearly. Of the 77 patients in whom cancer was detected radical prostatectomy was performed in 52. Pathological stage was pT2 in 48 patients and pT3 in 4, while Gleason score was 4 to 5, 6 to 7 and 8 in 5, 46 and 1, respectively. At prostatectomy median cancer volume was 1.04 cc and 85.7% of removed tumors were clinically significant, assuming a 3-year doubling time. The overall complication rate for saturation needle biopsy was 12% and hematuria requiring hospital admission was the most common event. Saturation needle biopsy of the prostate is a useful diagnostic technique in men at risk for prostate cancer with previous negative office biopsies. This technique allows adequate sampling of the whole prostate gland and has a detection rate of 34% in this cohort of patients.