Individualization of the biopsy protocol according to the prostate gland volume for prostate cancer detection

PURPOSE: In this study we assessed the relative yield of 10 core biopsy, and the whole range of alternative 8 and 6 core biopsy protocols over that of the classic sextant biopsy protocol. We determined the optimum number of cores per biopsy according to prostate volume in patients who experienced prostate biopsy for the first time. MATERIALS AND METHODS: A total of 503 men with the indications of abnormal digital rectal examination and/or serum prostate specific antigen greater than 2.5 ng/ml were included in the study. All patients underwent a 10 core biopsy protocol with an additional 1 core from each suspicious area detected by transrectal ultrasound. Prostate volume was divided into quartiles, namely 14.9 to 35, 35.1 to 50, 50.1 to 65 and 65.1 to 150 cc. The optimum number of biopsy cores was determined in patients with different prostate volumes. RESULTS: Median age was 63 years and prostate specific antigen was 7.4 ng/ml in the whole group. Of 503 patients 159 (31.6%) were positive for prostate cancer. Cancer detection rates decreased significantly from 49.6% to 20.8% as prostate volume increased in preset quartiles. Lesion biopsies revealed the lowest unique cancer detection rates for all prostate volume quartiles (0% to 3%). There was an obvious positive trend in cancer detection rates in favor of the 10 core biopsy protocol over sextant biopsies in all patient groups. Classic sextant biopsy protocol proved to be inadequate for all prostate volumes. Among sextant biopsy protocols laterally placed cores including the apex, lateral mid gland and lateral base had the best cancer detection rates (81% to 95%). The 8 core biopsy scheme consisting of the apex, mid gland, lateral mid gland and lateral base resulted in an only 1% lower detection rate (97%) than the 10 core biopsy protocol in the lowest quartile. The yield of the 10 core biopsy protocol in patients with a prostate volume of between 35.1 and 150 cc outscored that of the optimal 8 core biopsy scheme including the apex, base, lateral mid gland and lateral base with 3% to 8% differences in the cancer detection rate. CONCLUSIONS: The 10 core biopsy protocol must be used in all group of patients except patients with a prostate volume of 14.9 to 35 cc. In patients with a prostate volume of 14.9 to 35 cc the 8 core biopsy protocol consisting of the apex, mid gland, lateral mid gland and lateral base can be used since it revealed results similar to those of the 10 core biopsy protocol. The classic sextant biopsy protocol seemed inadequate for all prostate volumes. Patients with a larger prostate had lower cancer detection rates. Transrectal ultrasound directed lesion biopsies may be omitted when using 10 core biopsy protocols since the yield of these biopsies was less than 2%.     

Optimal combinations of systematic sextant and laterally directed biopsies for the detection of prostate cancer

PURPOSE: The standard sextant protocol for obtaining transrectal ultrasound guided biopsy of the prostate has been shown to underestimate the presence of prostate cancer. Studies have demonstrated an increased cancer detection rate with additional laterally directed biopsies. We compared the sensitivity of individual biopsy cores and evaluated combinations of these cores to identify an optimal biopsy strategy. MATERIALS AND METHODS: A total of 396 consecutive patients underwent biopsy of the lateral peripheral zone in addition to standard sextant biopsy. The cancer detection rate for each biopsy core was calculated. The sensitivity of different combinations of biopsy cores was compared with those of standard sextant biopsies and with a 12 core biopsy protocol that combined the standard sextant biopsy with a complete set of laterally directed cores. RESULTS: Cancer was detected in 160 of 396 (40.3%) patients. Of the possible combinations of biopsy cores a strategy that included laterally directed cores at the base, mid gland and apex of the prostate with mid lobar base and apical cores detected 98.5% of cancers. The detection rate of this 10 core biopsy regimen was significantly better than that of the standard sextant protocol (p < or =0.001), and was equivalent to that of the 12 core regional biopsy (p > or =0.302). CONCLUSIONS: The standard sextant protocol failed to detect a large proportion of cancers located laterally in the peripheral zone. A 10 core biopsy regimen that combined laterally directed cores at the base, mid gland and apex of the prostate with mid lobar biopsy cores at the base and apex maximizes the sensitivity of transrectal ultrasound guided systematic biopsy.     

Impact of prior biopsy scheme on pathologic features of cancers detected on repeat biopsies

The object of our study was to characterize the biopsy features of cancers detected in a repeat biopsy population stratified on the basis of the type of prior negative biopsy. We studied 218 patients with a prior negative biopsy who underwent a 10-core extended systematic biopsy scheme, and a subset (n = 139) underwent additional 6 anteriorly directed biopsies. Clinicopathologic features of patients with cancer on the biopsy were compared as a function of type of prior negative biopsy. Overall and unique cancer detection rates were calculated for each of the biopsy sites. Cancer detection rates tended to be higher in patients who had undergone a prior sextant biopsy compared to a prior extended biopsy scheme (39% vs. 28%). Trends towards more positive cores and greater total core length of cancer involvement were seen in patients who had undergone a prior negative sextant biopsy. Apical and laterally directed biopsies had higher overall and unique cancer detection rates in patients who had undergone a prior negative sextant biopsy. Anteriorly directed biopsies had a low unique cancer detection rate in all patients. We conclude that in patients undergoing repeat biopsy, the detection rate is affected by the extent of the prior biopsy. Clinicopathologic features of cancers detected on repeat biopsy tend to be worse in patients who have undergone a prior negative sextant biopsy compared to a negative prior extended biopsy.     

不同前列腺穿刺活检方案检出前列腺癌的比较

目的探讨理想的前列腺穿刺活检方案。方法临床表现怀疑前列腺癌患者214例，其中前列腺特异抗原〉4．0ng／ml 203例。均行13针前列腺穿刺活检术。年龄50～90岁，平均70岁；PSA水平0．8～112．3ng／ml，平均18．7ng／ml；前列腺体积12．3～182．5ml，平均61．3ml；直肠指诊阴性173例，阳性者41例。依穿刺结果，对比分析13针中6、8、10和13针穿刺阳性率。结果13针穿刺阳性率为36．0％（77／214）。在各种穿刺点组合中包含前列腺尖部、中部、底部、外侧中部、外侧底部的10针法能发现全部前列腺癌阳性病例的97．4％，与13针穿刺结果的差异无统计学意义（P=0．5）。结论对于初次前列腺活检的病例，包含尖部、中部、底部、外侧中部、外侧底部的10针法是较为合理的选择。     

Improved prostate cancer detection with anterior apical prostate biopsies

PURPOSE: Research to improve prostate cancer detection with transrectal ultrasound-guided prostate biopsies has focused on increasing the number of cores and the directing of biopsies laterally. In this study, we describe our experience with the addition of anterior apical biopsies. MATERIALS AND METHODS: A total of 164 consecutive patients with an increased or increasing prostate-specific antigen and/or abnormal digital rectal examination underwent transrectal ultrasound and systematic biopsy. We performed our standard laterally directed sextant biopsies plus additional mid parasagittal plane biopsies at the base and mid-gland, and an anteriorly directed biopsy at the apex. Site-specific detection and tumor characteristics are reported. RESULTS: Prostate cancer was detected in 71 patients (43.3%). The most commonly unique site was the anterior apex. Excluding these biopsies would have missed 17% of the cancers detected. The cancers limited to the anterior apex had tumor characteristics similar to all other cancers detected. CONCLUSION: In our experience, the anterior apical biopsies increase the detection of prostate cancer on transrectal ultrasound-guided biopsies. Further study on incorporating this site into the biopsy scheme is indicated.     

The utility of apical anterior horn biopsies in prostate cancer detection

We sought to determine the utility of adding apical anterior horn biopsies to systematic prostate sampling regimens in detecting cancer in men with measured prostate volume < or =50 cc. We reviewed the biopsy data of consecutive men referred for an abnormal digital rectal exam or PSA elevation > or =4.0 ng/mL. All of these patients underwent lesion directed biopsy as well as a systematic 12-core biopsy regimen consisting of the standard sextant, bilateral lateral mid- and lateral base-sites, and bilateral apical anterior horn sites. Overall cancer detection and unique cancer detection rates were calculated for each of the 12 sites, stratified by race, age, PSA, and findings on digital rectal exam. In addition, cancer detection rates of various biopsy schemes were calculated and compared. There were 255 men undergoing biopsy who had calculated prostate volume < or =50 cc, and the prostate cancer detection rate was 47%. The overall cancer detection rate of apical anterior horn biopsies ranged between 29% and 56%. The utility of these biopsies was greatest in men with normal rectal exam and PSA <10 ng/mL, with unique cancer detection rates of 6% and 4%, respectively. Including the apical anterior horn biopsies in an 8-biopsy scheme (anterior, apex, lateral mid, lateral base) yielded cancer detection rates greater than 91% in all subgroups that were not statistically different from extended 10- and 12-core biopsy regimens. Apical anterior horn prostate biopsies target cancers that are potentially in the anterior region of the prostate, a region under-sampled using traditional schemes. The use of these biopsies as part of an 8-core biopsy pattern provides high cancer detection in all groups of patients and may represent a new standard.     

Lateral biopsies added to the traditional sextant prostate biopsy pattern increases the detection rate of prostate cancer

Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error and data based upon whole-mounted step-sectioned radical prostatectomy specimens using a three-dimensional computer-assisted prostate biopsy simulator suggests that an increased detection rate is possible using laterally placed biopsies. The simulated 10-core biopsy pattern (traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland) was shown to be superior to the traditional sextant biopsy. The objective of this pilot study was to confirm the higher prostate cancer detection rate obtained using the 10-core biopsy pattern in patients. We reviewed data on 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core biopsy pattern. The frequency of positive biopsy was determined for each core. Additionally, the sextant and 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. Of the 35 patients diagnosed with prostate cancer, 54.3%(19/35) were diagnosed by the sextant biopsy only. The 10-core pattern resulted in an additional 45.7%(16/35) of patients being diagnosed solely with the laterally placed biopsies. The laterally placed biopsies had the highest frequency of positive biopsies when compared to the sextant cores. In conclusion, biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Prostate Cancer and Prostatic Diseases (2000) 3, 43-46     

The Effect of Prior Biopsy Scheme on Prostate Cancer Detection for Repeat Biopsy Population: Results of the 14-core Prostate Biopsy Technique

OBJECTIVES: To evaluate the diagnostic performance of 14-core repeat biopsy protocol and the impact of prior biopsy scheme on repeat prostate biopsy group. METHODS: 211 patients had repeat biopsy using 14-core protocol consisting of 10-core peripheral zone (classical sextant+4 lateral peripheral cores) and 4-core transitional zone (TZ) biopsies. The diagnostic yield was determined both in patients who had previously undergone sextant or 10-core biopsy protocol. RESULTS: Overall cancer detection rate was 25.6%. 14-core biopsy technique detected cancer in 36.1 and 18.7% of the patients who had a previous sextant biopsy and 10-core biopsy protocol, respectively (P = 0.005). Patients with and without high-grade prostatic intraepithelial neoplasia (HGPIN) in the previous sextant biopsy had 56.5 and 28.3% cancer detection rates on the subsequent extended biopsy, respectively (P = 0.017) Patients who had previous 10-core biopsy with and without HGPIN revealed 22.9 and 17.2% cancer detection rates, respectively (P = 0.465) Additional four lateral peripheral cores detected 33% (3/30) and 17% (4/24) of cancers in patients with previous sextant and 10-core biopsy, respectively. 3.7% of the patients had tumor only in the TZ and none of them had prior extended biopsy. CONCLUSIONS: The yield of extended 14-core repeat biopsy protocol was higher in patients with previous negative sextant biopsy compared to the patients with previous negative 10-core biopsy. HGPIN history found on previous sextant biopsy was a strong cancer predictor on repeat biopsy; same was not true for the patients with previous 10-core biopsy. The yield of lateral peripheral cores and TZ biopsies were lower in patients with prior negative extended biopsy.     

Correlation of positive prostate sextant biopsy locations to sites of positive surgical margins in radical prostatectomy specimens.

OBJECTIVE: To investigate whether sextant location of positive prostate biopsy predicts the site of positive surgical margins (PSM) at the time of radical prostatectomy (RP) in patients with clinical stage T1c prostate cancer. METHODS: A retrospective query of the Center for Prostate Disease Research (CPDR) database at our institution identified 456 patients with clinical stage T1c prostate cancer who underwent standard sextant prostate biopsy prior to RP. Each biopsy was submitted separately for pathologic analysis according to sextant location. The sextant location of positive biopsies was compared to the sites of PSM after RP. RESULTS: PSM were found in 129 of 456 (28%) RP specimens. The incidence of PSM at the prostate apex in patients with a positive or negative apical sextant biopsy was similar (9 and 8% respectively, p>0.05). The incidence of PSM at the prostate base in patients with a positive or negative sextant biopsy of the prostate base was also the same (7% in both groups, p>0.05). As the number of positive biopsy cores on one side of the prostate increased (0, 1, 2, and 3) so did the chance of an ipsilateral PSM (5.4, 16.2, 35.7 and 45.0%, respectively; p<0.005). CONCLUSIONS: Positive sextant biopsy location (apex and base) does not correlate with site of PSM at RP. However, ipsilateral PSM are more likely as the number of positive sextant biopsies on that side increases. While pathologic processing of biopsy specimens according to longitudinal prostate location (base, mid and apex) is probably unnecessary, the number of positive biopsies on a given side may be useful preoperative information.     

B超引导10点前列腺穿刺法诊断前列腺癌的结果分析

目的探讨经直肠超声引导下10点法前列腺穿刺活检中前列腺癌阳性结果的分布情况。方法本组473例均因PSA>4ng/ml而进行经直肠超声引导下10点法宝前列腺穿刺活检,穿刺点为在标准的系统6点(前列腺旁正中线矢状切面尖部、中部、底部)的基础上,两外侧各增加2针(外侧周缘中部、底部)。本组患者年龄为41～85岁,平均65岁;PSA水平4.1～444ng/ml,平均15.05ng/ml;前列腺体积8.0～160.0ml,平均42.17ml。对穿刺各针的阳性率及各区域独立出现的阳性率进行分析。结果穿刺总阳性率为26.6%(126/473)。前列腺各穿刺部位的阳性率为:外侧底部23.7%(112/473)、外侧中部20.7%(98/473)、底部19.5%(92/473)、中部18.4%(87/473)、尖部23.9%(113/473)。只有该区域出现阳性的分布情况:外侧底部8.7%(11/126)、外侧中部5.6%(7/126)、底部2.4%(3/126)、中部3.2%(4/126)、尖部7.1%(9/126)。各穿刺部位的阳性率具有统计学差异(P<0.01)。结论经直肠超声引导下经直肠前列腺10点法穿刺活检术可明显提高前列腺癌的临床检出率。其前列腺的尖部、外侧底部和外侧中部的穿刺阳性率要比其他部位高。     

Update on transrectal ultrasound-guided needle biopsy of the prostate

Over the past decade, the sextant biopsy technique has emerged as the standard of care in the detection of prostate cancer. This technique is easy to learn and well tolerated by patients and has a major complication rate of <1%. However, limitations in cancer detection have been appreciated, particularly a false-negative rate approaching 25%. This high failure rate has led investigators to refine biopsy techniques to improve cancer detection. Intuitively, increasing the total number of cores should improve cancer detection. However, the optimal core number has yet to be defined. Confounding factors include variability of prostate size, tumor volume, and tumor location. Currently, a new standard is emerging prescribing a minimum of eight cores, of which at least three are directed at the lateral aspect of the peripheral zone. These additional biopsies appear to enhance cancer detection by about 15%. The improved yield is most pronounced among patients with a serum prostate specific antigen concentration between 4 and 10 ng/mL and larger gland volume (>50 cc). These additional biopsies may decrease the need for repeat biopsies. In the meantime, strategies are being developed for the optimal technique of repeat biopsies among patients with persistent clinical suspicion in the setting of a prior negative biopsy. Currently, recommendations include increasing the biopsy number to a minimum of 10 cores, including sampling of the lateral peripheral and transition zones.     

Comparison of prostate biopsy schemes by computer simulation

OBJECTIVES: To compare the ability of different biopsy schemes to detect cancer and predict tumor volume using our previously described prostate biopsy simulation system. In addition, we used the simulation system to evaluate the optimal location of transition zone biopsies. METHODS: Digital reconstructions of 180 radical prostatectomy specimens were used. Forty simulations were performed on each prostate for 10 biopsy schemes, including a previously reported five-region peripheral zone biopsy pattern and a new 11-core multisite-directed scheme consisting of sextant, two transition zone, one midline, and two anterior horn biopsies. For simulation of the transition zone biopsies, paired near-midline biopsies were simulated, with needle insertion points from the apex to the base of the prostate and with needle advances of 1 to 4 cm before firing. A total of 1,180,800 individual biopsy tracks were simulated. RESULTS: The 11-core multisite-directed biopsy scheme had the highest detection rate for cancers greater than 0.5 cc. This scheme reliably detected cancer in 94% (138 of 147) of the cases. These results were significantly better than those of the sextant biopsy scheme (P <0.001) and the five-region 18-core peripheral zone scheme (P = 0.03). Compared with other schemes, there were increases in small-volume (0.5 cc or less) cancer detection by both the 11-core multisite-directed and five-region schemes, but they were not statistically significant. The multisite and the sextant plus four transition zone biopsy schemes had the best correlation of mean total core cancer length with total cancer volume. In the simulation of the transition zone biopsies, the highest detection rate was observed when the biopsies were initiated at the most apical section and inserted for a depth of 3 cm before firing. CONCLUSIONS: Our simulation results suggest that the detection rate of prostate biopsies is not related solely to the number of cores taken. Core placement (the regions of the prostate from which samples are taken) is also important. The 11-core multisite-directed biopsy scheme performed the best, with improved cancer detection rates and tumor volume correlation over other schemes. On the basis of our simulations, this scheme has been chosen for clinical evaluation.     

Update on prostate biopsy technique

PURPOSE OF REVIEW: Over the past decade, a considerable number of modifications have been made to the techniques for prostate cancer biopsy. In this review, we discuss the developments reported in the literature since January 2003. RECENT FINDINGS: The addition of laterally directed biopsies has enhanced the diagnostic performance of the conventional sextant biopsy approach. Several models of the extended biopsy technique have been introduced that increase the number of cores by combining sextant and lateral biopsies to enhance the cancer detection rate. Several reports have shown that the cancer detection rate decreases as prostate volume increases, compared with an increasing cancer detection rate on repeat biopsy in men with large prostate gland volumes. Other studies have shown that the percentage of positive cores and the total percentage of tumor found at biopsy are significant independent predictors of pathological outcome on multivariate analysis. In randomized, double-blind studies, infiltration of the neurovascular bundles with lidocaine significantly reduces pain associated with extended biopsies. SUMMARY: Current reports have suggested that: (1) extended biopsy schemes decrease the false-negative rate compared with conventional sextant biopsy; (2) laterally directed biopsies from the anterior horn should be included in extended biopsy protocols; and (3) local anesthesia reduces pain associated with extended biopsy.     

Are extended biopsies really necessary to improve prostate cancer detection?

The aim of this study is to understand the value of specific sites in extended peripheral and transition zone biopsy schemes in order to define the optimal systematic biopsy regimen correlated with the percentage of positivity of each single bioptic site. A total of 165 consecutive patients underwent transrectal ultrasonography examination to detect prostate cancer followed by a lesion-directed and systematic 14-step biopsy scheme. The detection rate was examined for the lesion-directed and for each zone region biopsy. The frequency of positive biopsies in the various prostate regions was determined to evaluate the diagnostic yield of each biopsy site. Analysis was stratified for prostate-specific antigen (PSA), free-to-total PSA ratio, age, prostate size and digital rectal examination. The biopsy protocol detected 40% of patients (66/165) as positive and 55.1% (91/165) as negative for cancer. Standard sextant biopsy was expected to detect only 51 cancer on 66, lateral peripheral (PZ), transition (TZ) and central zone (CZ) biopsies only 56 cancer on 66, while the combination of sextant, PZ, TZ and CZ biopsies, for a total of 14 zone biopsies, detected 64 on 66 patients with cancer (97%) at recruitment. Sampling only the eight prostate regions with higher frequency of positive cancer biopsy was expected to detect 61 cancer patients against the 64 found with the 14-step scheme. This eight-biopsy regimen outperforms the conventional sextant regimen in cancer detection rate (93 vs 77%) and has an overall detection rate lower by only 3.1% (36.9 vs 40%) compared to the 14-biopsy regimen. This difference in detection rate is even smaller in patients with PSA values <10 ng/ml, age <70 y and prostate size <50 ml. This eight-biopsy scheme, including sampling in PZ and TZ toward the base, should be considered in an initial biopsy scheme to maintain a similar detection rate of an extensive biopsy scheme reducing the number of biopsies.     

Cancer detection rates of different prostate biopsy regimens in patients with renal failure

We aimed to evaluate the cancer detection rates of 6-, 10-, 12-core biopsy regimens and the optimal biopsy protocol for prostate cancer diagnosis in patients with renal failure. A total of 122 consecutive patients with renal failure underwent biopsy with age-specific prostate-specific antigen (PSA) levels up to 20?ng/mL. The 12-core biopsy technique (sextant biopsy?+?lateral base, lateral mid-zone, lateral apex, bilaterally) performed to all patients. Pathology results were examined separately for each sextant, 10-core that exclude parasagittal mid-zones from 12-cores (10a), 10-core that exclude apex zones from 12-cores (10b) and 12-core biopsy regimens. Of 122 patients, 37 (30.3%) were positive for prostate cancer. The cancer detection rates for sextant, 10a, 10b and 12 cores were 17.2%, 29%, 23.7% and 30.7%, respectively. Biopsy techniques of 10a, 10b and 12 cores increased the cancer detection rates by 40%, 27.5% and 43.2% among the sextant technique, respectively. Biopsy techniques of 10a and 12 cores increased the cancer detection rates by 17.1% and 21.6% among 10b biopsy technique, respectively. There were no statistical differences between 12 core and 10a core about cancer detection rate. Adding lateral cores to sextant biopsy improves the cancer detection rates. In our study, 12-core biopsy technique increases the cancer detection rate by 5.4% among 10a core but that was not statistically different. On the other hand, 12-core biopsy technique includes all biopsy regimens. We therefore suggest 12-core biopsy or minimum 10-core strategy incorporating six peripheral biopsies with elevated age- specific PSA levels up to 20?ng/mL in patients with renal failure.     

Prostate biopsy strategies

Early detection is critical to good management of prostate cancer patients. Markers for detection, such as prostate specific antigen (PSA), and prostate biopsy are paramount for establishing an efficient diagnosis. Patients having an initial biopsy should undergo an extended biopsy scheme incorporating at least 10-12 cores, while in those undergoing a repeat biopsy particular attention should be addressed to the anterior apex. Saturation biopsies should be considered for patients with several prior negative biopsies. The chance of finding cancer on repeat biopsies has diminished in patients harboring high-grade prostatic intraepithelial neoplasia but not in those with atypical small acinar proliferation. This article reviews the history of prostate biopsy strategies with particular attention paid towards the development of extended biopsy schemes. Furthermore, a strategy is recommended for initial and repeat biopsy patients.     

Prostate cancer detection with office based saturation biopsy in a repeat biopsy population

PURPOSE: Patients at increased risk for prostate cancer with previously negative biopsies pose a diagnostic challenge. We have previously demonstrated that extensive saturation biopsy can be performed in an office setting. We now report the diagnostic yield of office saturation biopsy in patients at increased risk for prostate cancer and at least 1 negative prior biopsy. MATERIALS AND METHODS: We performed saturation prostate biopsy with local anesthesia in the office in 116 patients with at least 1 prior negative biopsy and with certain risk factors, namely persistently elevated prostate specific antigen, abnormal digital rectal examination, or prior atypia or PIN on prior biopsy. RESULTS: A total of 34 cancers were detected for an overall diagnostic yield of 29%. A 64% detection rate was noted when a patient had undergone a single prior sextant biopsy. Subgroup analysis revealed a cancer detection rate of 41% when only prior sextant biopsies were performed, and a 24% detection rate when 10 or more cores were taken on prior biopsy. The detection rate was 33% when only 1 prior biopsy was taken and it was 24% when 2 or more prior biopsies were performed. CONCLUSIONS: Saturation biopsy can be performed safely and effectively in the office with a significant diagnostic yield even in patients with previous extended biopsy schemes. We believe that it should be the next diagnostic step after an initial negative biopsy in patients in whom the diagnosis of prostate cancer is strongly suspected.     

Critical evaluation of the current indications for transition zone biopsies

Objectives. Two primary indications for the performance of anteriorly directed transition zone (TZ) biopsies are (a) an elevated prostate-specific antigen (PSA) level and an enlarged, non-nodular prostate and (b) prior negative sextant biopsies of the prostate. These indications are, however, based on a study population evaluated early in the PSA era (1989 to 1992). The current analysis targeted a more contemporary series of patients (1995 to 2000) presenting with these two indications for TZ biopsies, who underwent ultrasound scanning and biopsies by the same examiner and with the same equipment as in the earlier series.Methods. We evaluated 390 men, 274 (70.3%) of whom underwent sextant plus TZ biopsies for elevated PSA levels and an enlarged, non-nodular prostate; 116 (28.7%) underwent this biopsy strategy because of an elevated or rising PSA in whom prior sextant biopsies had not revealed cancer.Results. Of the 274 patients who underwent initial sextant biopsies plus anterior biopsies for an enlarged, non-nodular prostate, 49 (17.9%) were found to have adenocarcinoma and in only 4 (1.5%) did only the TZ biopsies reveal cancer. Of the 116 patients who underwent TZ biopsies after prior negative sextant biopsies, 36 (31.0%) were found to have prostate cancer and in 11 (9.5%) only the TZ biopsies demonstrated cancer.Conclusions. The cancer detection rate for sextant plus TZ biopsies in this contemporary series of patients presenting with enlarged, non-nodular prostates was substantially lower than the rate in earlier reports (1.5% compared with 36.9%), despite the consistency in the equipment and examining physician. This may have been due to the stage migration of prostate cancer, which has been observed as a result of the widespread use of PSA measurement for early detection. Sextant plus TZ biopsies are more productive in patients with prior negative biopsies who have a persistent clinical suspicion for prostate cancer on the basis of an elevated and/or rising PSA level.     

Computer simulated additional deep apical biopsy enhances cancer detection in palpably benign prostate gland

OBJECTIVES: The objective of this study was to use computer simulation to investigate the optimal biopsy scheme for enhancing the detection of cancer in palpably benign prostate glands. METHODS: The predominant distribution of palpably benign prostate cancer is anterior apex to mid-prostate. We used computer simulation to optimize apical samplings and to simulate the biopsy procedure, including angle and length. A total of 254 consecutive patients with palpably benign prostate glands underwent sextant biopsy plus two additional deep apical biopsies. RESULTS: Based on the computer simulation, lateral sextant and two additional medially located deep apical cores with a sagittal penetration angle of 80 degrees had the maximum cancer detection. Of the 254 patients, 58 (22.8%) had prostate cancer: 28 (48.3%) were positive only at the standard sextant sites, 12 (20.7%) were positive exclusively at the deep apical sites, and the remaining 18 (31.0%) were positive at both sites. Patients with gray-zone prostate-specific antigen (PSA) ranges of 4.1-10.0 ng/mL had increased cancer detection rates of 24% compared to sextant biopsy. Enhanced cancer detection by the deep apical biopsy was also evident in patients with a prostatic volume >40 cm3 (by 36.4%) and PSA 2.1-4.0 ng/mL (by 13.3%). CONCLUSIONS: Using a computer simulation-based biopsy scheme with deep apical sampling cores enhanced the detection of prostate cancer in palpably benign glands, especially in men with PSA ranges of 4.1-10.0 ng/mL or a gland volume of >40 cm3. Our approach with fewer sampling cores may have been more cost-effective than other extensive biopsy schemes, but further studies with larger samples are warranted.     

Extended 21-sample needle biopsy protocol for diagnosis of prostate cancer in 1000 consecutive patients

OBJECTIVE: To prospectively evaluate the diagnostic yield of a 21-sample ultrasound-guided needle biopsy protocol as the initial diagnostic strategy for detection of prostate cancer. MATERIALS AND METHODS: Between December 2001 and October 2005, 1000 consecutive patients underwent 21-sample needle biopsies under local anesthesia, comprising sextant biopsies, 3 additional posterolateral biopsies in each peripheral zone, 3 biopsies in each transition zone (TZ), and 3 biopsies in the midline peripheral zone. Each prostate core was numbered and analyzed separately. The patients were divided into subgroups according to the result of digital rectal examination (DRE), serum prostate-specific antigen (PSA), and prostate volume. We evaluated the cancer detection rate overall and in each subgroup. We compared the results of our biopsy protocol to those from 6-, 12-, and 18-core biopsy protocols by analyzing only those cores from our protocol that would correspond to these biopsy schemes. RESULTS: Cancer detection rates using 6 biopsy samples (sextant biopsies only), 12 samples (sextant plus lateral biopsies), 18 samples (sextant, lateral, and TZ biopsies), and 21 samples (sextant, lateral, TZ, plus midline biopsies) were 31.7%, 38.7%, 41.5%, and 42.5%, respectively. The 12-sample procedure improved the cancer detection rate by 22% compared with the 6-sample procedure (p=0.0001). The improvement in the diagnostic yield was most marked in patients with a prostate volume > or =55 ml (36.9%), in patients with normal DRE (26.6%), and in patients with PSA<4 (37.5%). The addition of TZ biopsies to a 12-biopsy scheme increased the diagnostic yield by 7.2% overall (p=0.023). Only 10 of 425 (2.3%) patients were diagnosed on the sole basis of midline biopsies. CONCLUSIONS: Patients with suspected localized prostate cancer should be offered at least 12 biopsies in the peripheral zone and far lateral peripheral zone (statistically significant). TZ biopsies have to be considered, because these biopsies improve the diagnostic yield. For patients with abnormal DRE and/or PSA> or =20 ng/ml, the 6-biopsy scheme seems sufficient (statistically), but 6 far lateral peripheral zone biopsies as well as the TZ biopsies add little incremental value (not significant). Evidence does not support the use of routine midline peripheral zone needle biopsies in the initial biopsy to enhance the detection of prostate cancer.