Is quadrant biopsy sufficient in men likely to have advanced prostate cancer? Comparison with extended biopsy.

We hypothesized that quadrant prostate biopsy (QPB) provides sufficient first-line pathological evaluation of patients with presumed advanced prostate cancer (PC). The aim of this study was to investigate whether the reduction of core number in first-line PB from 6-12 to 4 in patients with presumed advanced PC leads to loss of clinically relevant information. We retrospectively studied 113 men that underwent PB, classified in two groups: "H" (high) and "L" (low likelihood of having advanced PC), according to PSA, digital rectal and transrectal ultrasound findings. Pathological results of 6-12-core PB and QPB were retrospectively compared for the presence of malignancy, percentage of positive cores, Gleason score (GS), and the presence of high-grade prostatic intraepithelial neoplasia (HGPIN). PC detection rate was not impaired in group H but dropped significantly in group L, and the percentage of positive cores was not significantly changed in group H (p=0.39), but decreased in group L (p=0.04), due to sampling scheme reduction. No HGPIN was missed with QPB in group H, while 2 HGPINs were missed in group L. No significant change in GS in either group was observed (p=0.12, p=0.13) due to reduction to QPB. We conclude that in patients with presumed advanced PC, reduction of the number of cores in PB may be an acceptable diagnostic strategy, but further studies are needed to analyze the impact of PB scheme reduction on other relevant pathological information obtained from PB.