Saturation Technique Does Not Decrease Cancer Detection During Followup After Initial Prostate Biopsy

Abstract

It has been reported that the prostate cancer detection rate in men with prostate specific antigen 2.5 ng/ml or greater undergoing saturation (20 cores or greater) prostate biopsy as an initial strategy is not higher than that in men who undergo 10 to 12 core prostate biopsy. At a median followup of 3.2 years we report the cancer detection rate on subsequent prostate biopsy in men who underwent initial saturation prostate biopsy. Saturation prostate biopsy was used as an initial biopsy strategy in 257 men between January 2002 and April 2006. Cancer was initially detected in 43% of the patients who underwent saturation prostate biopsy. In the 147 men with negative initial saturation prostate biopsy followup including digital rectal examination and repeat prostate specific antigen measurement was recommended at least annually. Persistently increased prostate specific antigen or an increase in prostate specific antigen was seen as an indication for repeat saturation prostate biopsy. During the median followup of 3.2 years after negative initial saturation prostate biopsy 121 men (82%) underwent subsequent evaluation with prostate specific antigen and digital rectal examination. Median prostate specific antigen remained 4.0 ng/ml or greater in 57% of the men and it increased by 1 ng/ml or greater in 23%. Cancer was detected in 14 of 59 men (24%) undergoing repeat prostate biopsy for persistent clinical suspicion of prostate cancer. No significant association was demonstrated between cancer detection and initial or followup prostate specific antigen, or findings of atypia and high grade prostatic intraepithelial neoplasia on initial saturation prostate biopsy. Cancers detected on repeat prostate biopsy were more likely to be Gleason 6 and organ confined at prostatectomy than were those diagnosed on initial saturation prostate biopsy. Previous experience suggests that, while office based saturation prostate biopsy improves cancer detection in men who have previously undergone a negative prostate biopsy, it does not improve cancer detection as an initial biopsy technique. We now report that the false-negative rate on subsequent prostate biopsy after initial saturation prostate biopsy is equivalent to that following traditional prostate biopsy. These data provide further evidence against saturation prostate biopsy as an initial strategy.