Is Quantitative Histologic Examination Useful to Predict Nonorgan-Confined Prostate Cancer When Saturation Biopsy Is Performed?

Objectives

To evaluate the role of quantitative histologic findings in predicting nonorgan-confined (non-OC) prostate cancer (PCa) in patients undergoing saturation prostate biopsy (SPBx).

Methods

A total of 69 patients who had undergone SPBx underwent radical retropubic prostatectomy. Their prostate-specific antigen level was <10 ng/mL, and 49 and 20 patients had T1c and T2 PCa, respectively. The following biopsy variables from the quantitative histologic examination were evaluated as predictive of OC vs non-OC PCa: Gleason score (≤6 vs >6), total percentage of PCa (≤20% vs >20%), greatest percentage of PCa (≤50% vs >50%), number of PCa-positive cores (≤2 vs >2), presence of PCa-positive cores in both lateral margins (yes vs no), and PCa localization (unilateral vs bilateral). The results obtained from patients who had undergone SPBx were compared with those of 183 patients who had undergone 12-core prostate biopsy before radical retropubic prostatectomy.

Results

Overall, 32 patients had non-OC PCa. Among the men with Stage T1c PCa, the quantitative histologic findings were predictive of non-OC PCa in 12 of 17 cases. The area under the receiver operating characteristic curve was 0.935 ± 0.29, supporting the high accuracy of quantitative histologic examination in predicting for non-OC PCa. The sensitivity in patients who underwent SPBx vs the 12-core biopsy was 78.1% and 89.4%, respectively. Also, although the specificity of each histologic parameter was significantly lower in the SPBx group, it was equivalent using quantitative histologic examination (85.6% vs 86.5%).

Conclusions

In the preoperative staging of patients with clinical Stage T1c-T2 PCa and a prostate-specific antigen level <10 ng/mL who had undergone SPBx, quantitative histologic examination demonstrated good accuracy in predicting for non-OC PCa only when all pathological variables were considered.