Evaluating limited biopsy templates for men with markedly elevated PSAs

To define the smallest prostate needle biopsy (PNB) template necessary for accurate tissue diagnosis in men with markedly elevated PSA while decreasing procedural morbidity.

We performed a chart review of 80 men presenting with a newly elevated PSA > 100 ng/mL who underwent biopsy (PNB or metastatic site). For patients who underwent a full 12-core biopsy, simulated templates of 2- to 10-cores were generated by randomly drawing subsets of biopsies from their full-template findings. Templates were iterated to randomize core location and generate theoretical smaller template outcomes. Simulated biopsy results were compared to full-template findings to determine accuracy to maximal Grade Group (GG) diagnosis.

Amongst those that underwent PNB, 93% had GG 4 or 5 disease. Twenty-two (40%) underwent a full 12-core biopsy, 20 (37%) a 6-core biopsy, and only 8 (15%) had fewer than six biopsy cores sampled at our hospital. Simulated templates with 2-, 4-, 6-, and 8-cores correctly diagnosed prostate cancer in all patients, and accurately identified the maximal GG in 82%, 91%, 95%, and 97% of patients, respectively. The biopsy locations most likely to detect maximal GG were medial mid and base sites bilaterally. A 4-core template of these sites would have accurately detected the maximal GG in 95% of patients relative to a full 12-core template.

In men presenting with PSA > 100 ng/mL, decreasing from a 12-core to a 4-core prostate biopsy template results in universal cancer detection and minimal under-grading while theoretically decreasing procedural morbidity and cost.