Elsevier

Urology

Volume 60, Issue 5, November 2002, Pages 841-845
Urology

Adult urology
Increasing the number of core samples taken at prostate needle biopsy enhances the detection of clinically significant prostate cancer☆

https://doi.org/10.1016/S0090-4295(02)01878-2Get rights and content

Abstract

Objectives

The number of cores obtained during transrectal ultrasound-guided prostate biopsy to detect cancer has increased from the previous standard of 6. Increasing the number of biopsy cores taken results in a higher prostate cancer detection rate. Because criteria for defining the clinical significance of localized prostate cancer has been proposed, the question may be asked whether the increased number of tumors found is clinically significant.

Methods

The Urology Service’s surgical log database revealed 369 patients who underwent radical prostatectomy as primary therapy between January 1997 and March 2001. Only men who had had more than six core biopsies that included the standard sextant and lateral horns of the peripheral zone biopsies were considered. The hospital’s clinical information system was then used to extract all additional data for age, clinical stage, pretreatment prostate-specific antigen level, and transrectal ultrasound-guided biopsy and subsequent whole mount pathology results, including pathologic stage, number of tumors, largest single and aggregate tumor volumes, highest tumor Gleason score, and tumor locations. A total of 127 men comprised our final group.

Results

Subgrouping based on the location of positive biopsy results yielded 40 (31.5%) in the standard sextant biopsy only, 31 (24.4%) in the lateral horns of the peripheral zone only, and 56 (44.1%) of 127 tumors in both zones. The Gleason score was similar throughout. The margin-positive rate was 12.5% for the sextant-only positive biopsies, 12.9% for the lateral horn-only positive biopsies, and 42.9% for the both positive biopsies. The insignificant tumor rate for the group as a whole was 5.5% (7 of 127). The insignificant tumor rate for the lateral horn-only positive biopsies was 3.2% (1 of 31).

Conclusions

The addition of laterally directed biopsies increases the rate of prostate cancer detection, and the vast majority of these tumors are clinically significant.

Section snippets

Material and methods

Between January 1997 and March of 2001, 369 radical retropubic prostatectomies were performed at Walter Reed Army Medical Center and entered into the Urology Service’s surgical log database. The hospital’s clinical information system was then used to identify those patients who underwent a prostate needle biopsy that included more than six core samples. Between 1997 and 1999, studies were underway at our institution to determine the optimal biopsy schematic for detection of prostate cancer. As

Results

For the overall group of 127 patients, the mean age at diagnosis was 60.16 ± 6.96 years (range 42 to 73), and the mean PSA value was 6.76 ± 3.69 ng/mL (range 0.90 to 23.40). The most common clinical stage and number of prostate needle biopsy cores taken was T1c and 10, respectively. The most common Gleason score was 6. Of the 127 patients, 21 (16.53%) had cancer that was too small to assign a Gleason grade on all positive cores. The most frequent pathologic stage was T2b, with 4 (range 1 to 14)

Comment

Since the introduction of PSA screening, the number of prostate needle biopsies performed annually has risen. One question raised at the time of PSA implementation was whether these tumors represented clinically significant disease or were biologically inert and therefore amenable to conservative approaches. Epstein et al.2 were able to show that only 16% of such tumors could be classified as clinically insignificant. Clinically insignificant tumors were less than 0.2 cm3 and organ confined,

Conclusions

Laterally directed biopsies reveal what appear to be a significant number of prostate cancers, as do standard sextant cores. Increasing the number of core samples taken at the time of prostate needle biopsy does not seem to compromise the relevance of the tumors found. Very few tumors represent insignificant disease. If the clinical suspicion for prostate cancer exists, a needle biopsy scheme that includes the standard sextant cores and lateral horn of the peripheral zone sites will not only

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☆

The opinions and assertions contained herein are the private views of the authors and are not to be construed as reflecting the views of the U.S. Army, Air Force, Navy, or Department of Defense.

This research was approved by the Department of Clinical Investigation, Walter Reed Army Medical Center, Washington, DC, WU No. 01-28007E

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