Value of repeat ultrasonic prostatic biopsies following negative digitally directed biopsy.

OBJECTIVE: The objective of this study was to determine the benefit of repeat transrectal ultrasound-guided prostatic biopsy (TRUSBx) among men with prior benign histology on digitally guided biopsy despite suspicious digital rectal examination (DRE) findings. PATIENTS AND METHODS: From January 1, 1990 to May 30, 1993, we evaluated 130 consecutive men, referred to us with benign pathology on digitally-guided biopsy and DRE suspicious of cancer. All patients underwent systematic and directed TRUSBx. RESULTS: TRUSBx detected previously undiagnosed malignancy in 67 cases (51%). CONCLUSION: It is mandatory to reevaluate by TRUSBx, all patients with a palpable abnormality on DRE and a prior benign pathology on digitally-guided biopsy, as the likelihood of finding cancer is elevated.

Analysis of gland volume effect on the performance of PSA density in early detection of non-palpable, isoechoic prostate cancer.

OBJECTIVE: To reassess PSA density (PSAD) in the detection of non-palpable, isoechoic prostate cancer and to analyze the effect of potentially inaccurate non-planimetric transrectal ultrasound volume estimates on the diagnostic performance of this diagnostic tool. METHODS: We prospectively evaluated 343 consecutive men with non-suspicious digital rectal examination and transrectal ultrasound findings and with serum PSA in the intermediate range (4.1-10 ng/mL). All men underwent systematic sextant biopsies of the peripheral zone. We performed a two-fold analysis of PSAD performance first using measured gland volume and then using modified gland volumes ranging from a 25% underestimation to a 25% overestimation, in 5% stepwise increments. RESULTS: With a 0.15 PSAD cut-off, we would have missed 14, 34 and 48% of cancers, if we had respectively used a volume underestimate of 25%, the measured volume and a volume overestimate of 25%. CONCLUSIONS: Potential gland volume under- or overestimation may substantially affect the diagnostic performance of PSAD. Although PSAD may represent a useful adjunct in the early detection of prostate cancer, it may compromise cancer detection in a substantial proportion of cases, if used as the only indicator for biopsy.