Objectives: Six random systematic core biopsies (SRSCB) of the prostate is considered by many to represent the standard method of detecting prostate cancer. We sought to evaluate the sensitivity of the transrectal ultrasound (TRU)S-guided needle biopsies in 89 consecutive patients with a history of biopsy-proven prostate cancer. These patients underwent repeat biopsy prior to enrollment in an ongoing, randomized protocol. We also compared the clinical and pathological features of patients with SRSCB-documented prostate carcinoma and negative repeat-sextant biopsy.
Methods: Our study population consisted of 89 patients enrolled in our randomized, prospective study assessing the effect of androgen deprivation therapy in combination with radical prostatectomy for clinically localized prostate cancer. A comparison was made of the patients' rebiopsy results with initial biopsy. Patients having either a positive or negative rebiopsy were analyzed with respect to grade, T stage, prostate-specific antigen (PSA), PSA density (PSAD), organ-confined rate, and final surgical margin status.
Results: Repeat sextant biopsy was positive for prostate cancer in 71 (80%) patients and negative in 18 (20%) patients. There was no significant difference between patients with a negative or positive rebiopsy with respect to PSA or PSAD. There was a trend toward greater prostate volumes in the negative-rebiopsy group (P = 0.08) and lower clinical stage in the negative rebiopsy (P = 0.025) group. In patients with a negative repeat biopsy, the organ-confined (OC) rate was 77% (14/18 patients), as compared to the positive-rebiopsy group of 56% (40/71 patients) (P = 0.08). Similarly, the margin-positive rate in the negative-rebiopsy group was 17% (3/18 patients), as compared to the positive-rebiopsy group who had a margin-positive rate of 44% (31/71 patients) (P = 0.03).
Conclusions: In patients with clinically localized disease, the sensitivity of SRSCB in detecting carcinoma is 80%. The results of this study highlight the potential sampling error of the SRSCB and the implication of a negative rebiopsy in patients with clinically significant prostate cancer.