Prospective evaluation of a 21-sample needle biopsy procedure designed to improve the prostate cancer detection rate

Abstract

Objectives: To evaluate prospectively the diagnostic yield of a 21-sample ultrasound-guided needle biopsy procedure for prostate cancer in patients with elevated serum prostate-specific antigen and/or abnormal digital rectal examination findings.

Methods: Between December 2000 and May 2002, 303 patients underwent 21-sample needle biopsy under local anesthesia, comprising sextant biopsies at a 45 degrees angle, 3 biopsies in each peripheral zone at an 80 degrees angle, 3 biopsies in each transition zone (TZ), and 3 biopsies in the midline peripheral zone. Morbidity was assessed clinically. A short questionnaire was filled out by 90 consecutive patients.

Results: The cancer detection rate using 6 biopsy samples (sextant biopsies only), 12 samples (sextant plus lateral biopsies), 18 samples (sextant plus lateral plus TZ biopsies), and 21 samples (sextant plus lateral plus TZ, plus midline biopsies) was 22.7%, 28.3%, 30.7%, and 31.3%, respectively. The 21-sample procedure statistically improved the cancer detection rate by 37.9% relative to the 6-sample procedure. The improvement was most marked in patients with a prostate volume of more than 40 cm(3) (48.3%), patients with Stage T1c prostate disease (44.9%), patients undergoing repeat biopsy (66.2%), and patients with prostate-specific antigen levels greater than 10 ng/mL (38.5%). Adverse effects were infrequent (3%), consisting of prostatitis in 3 patients, acute urinary retention in 6 patients, and rectal bleeding requiring hospitalization in 1 patient taking aspirin. Using the questionnaire, 84% of patients reported macroscopic hematuria for an average of 3.4 days and hematospermia for 12.8 days, and 45% reported minor rectal bleeding lasting 1.1 days. The mean pain score, with a visual analog scale ranging between 0 (no pain) and 10 (intense pain), was 4.56.

Conclusions: A 21-sample needle biopsy procedure increased the prostate cancer detection rate relative to a 6-sample procedure, without increasing morbidity. Patients with elevated prostate-specific antigen values should undergo sextant biopsies and at least 6 additional biopsies in the peripheral zone and 6 in the TZ.