Evaluating limited biopsy templates for men with markedly elevated PSAs.

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

Materials and methods: 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.

Results: 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.

Conclusions: 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.