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.     

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.     

Ultrasound-guided transrectal extended prostate biopsy： a prospective study

AIM: To evaluate the diagnostic value of the 10 systematic transrectal ultrasound-guided (TRUS) prostate biopsy compared with the sextant biopsy technique for patients with suspected prostate cancer. Methods: One hundred and fifty-two patients with suspected prostate cancer were included in the study. Patients were entered in the study because they presented with high levels of prostate specific antigen (PSA) (over 4 ng/mL) and/or had undergone an abnormal digital rectal examination (DRE). In addition to sextant prostate biopsy cores, four more biopsies were obtained from the lateral peripheral zone with additional cores from each suspicious area revealed by transrectal ultrasound. Sextant, lateral peripheral zone and suspicious area biopsy cores were submitted separately to the pathological department. Results: Cancer detection rates were 27.6% (42/152) and 19.7% (30/152) for the 10-core and sextant core biopsy protocols, respectively. Adding the lateral peripheral zone (PZ) to the sextant prostate biopsy showed a 28.6% (12/42) increase in the cancer detection rate in patients with positive prostate cancer (P < 0.01). The cancer detection rate in patients who presented with elevated PSA was 29.3% (34/116). When serum PSA was 4-10 ng/mL TRUS-guided biopsy detected cancer in 20.6%, while the detection rate was 32.4% and 47.0% when serum PSA was 10-20 ng/mL and above 20 ng/mL, respectively. Conclusion: The 10 systematic TRUS-guided prostate biopsy improves the detection rate of prostate cancer by 28.6% when compared with the sextant biopsy technique alone, without increase in the morbidity. We therefore recommend the 10-core biopsy protocol to be the preferred method for early detection of prostate cancer.     

Improving prostate cancer detection with an extended-core transrectal ultrasonography-guided prostate biopsy protocol

OBJECTIVE: To investigate whether taking two transition zone (TZ) and four lateral peripheral zone (PZ) biopsies in addition to routine parasaggital sextant biopsies would improve detection rates in men with suspected prostate cancer. PATIENTS AND METHODS: The study included 493 consecutive men (mean age 68.7 years, sd 8.2) with elevated serum prostate-specific antigen (PSA) levels and/or abnormal findings on a digital rectal examination who underwent transrectal ultrasonography-guided prostate biopsy. In addition to sextant biopsies, six further biopsies were obtained, two from the TZ (mid-gland) and four from the lateral PZ (base and mid-gland). Pathological findings for the additional biopsies were compared with those of the sextant regions. RESULTS: Prostatic adenocarcinoma was diagnosed in 164 of the 493 (33%) men biopsied. Men with cancer were older, had smaller prostates and higher median PSA levels than men with negative biopsies. Sextant biopsies were positive for cancer in 133 of 164 (81%) men. All three sets of biopsies were positive in 53 (32%) cases. In 50 (30%) men both the sextant and lateral PZ biopsies were positive, while in six (4%) men, both sextant and TZ biopsies were positive. Thirty-one (19%) tumours were not detected by sextant biopsies, 10 (6%) where the lateral PZ biopsies alone were positive, 17 (10%) where the TZ biopsies alone were positive and four (3%) where both the TZ and lateral PZ together were positive. There were no differences in median PSA concentration, total prostate volume or TZ volume between men with an isolated TZ cancer and men with cancer elsewhere in the prostate. However, 77% of men with TZ cancer had a PSA of > 10 ng/mL, compared with 60% of men with cancer at other sites within the prostate (P = 0.015). CONCLUSION: An extended-core biopsy protocol significantly improves the detection rate for prostate cancer when compared with the standard sextant biopsy protocol alone. Routine TZ biopsies should be considered for men with serum PSA levels of >10 ng/mL.     

Effect of peripheral biopsies in maximising early prostate cancer detection in 8-, 10- or 12-core biopsy regimens

OBJECTIVE: To assess the cancer detection rate per individual core biopsy in a 12-core protocol and develop an optimal biopsy regimen for detecting early prostate cancer. PATIENTS AND METHODS: The study included 445 new patients who had a 12-core transrectal ultrasonography (TRUS)-guided prostatic biopsy over a 40-month period. The 12- core biopsy protocol included parasagittal sextant and six peripheral biopsies. The cancer detection rate per individual core was evaluated to give an optimal biopsy protocol. RESULTS: Prostate cancer was detected in 142 patients (31.9%). Parasagittal sextant biopsy would have failed to detect 40 (28.2%) of the cancers. Among the various possible biopsy protocols, the optimum 10-core biopsy strategy excluding the parasagittal mid-zone biopsies from the 12-core protocol achieved a cancer detection rate of 98.6%. CONCLUSION: The cancer detection rate increased from 71.8% for parasagittal sextant biopsies to 88.7% by adding peripheral basal biopsies (8-biopsy protocol); 98.6% of cancers in the series would have been detected with a 10-biopsy strategy omitting the parasagittal mid-zone biopsies. Thus we recommend a 10-core protocol incorporating six peripheral biopsies in patients with elevated age- specific prostate-specific antigen levels (2.6-10.0 ng/mL) for maximising cancer detection.     

超声引导前列腺12针系统穿刺活检术

目的　探讨经直肠超声引导下前列腺12针系统穿刺活检术诊断前列腺癌的临床价值。　方法　对220例行经直肠B超引导下前列腺12针(在传统6针基础上增加前列腺两侧外周带外侧底、中、尖部各1针)系统穿刺活检术的患者资料进行回顾性分析。　结果　前列腺癌患者73例(33. 2% ),临床分期T1 4例、T2 21例、T3 15例、T4 33例,如按传统6针穿刺方法穿刺,检出率为31. 4%,将有4例早期癌(T1 3例、T2 1例,体积均<0. 5ml)患者漏诊, 6针较12针穿刺漏诊早期癌16% (4 /25)。220例患者均未出现严重并发症。　结论　12针较6针系统穿刺活检可以增加早期癌和小体积癌( <0. 5ml)的检出,应重视对前列腺外周带外侧6点的穿刺。     

Three-dimensional computer-simulated prostate models: lateral prostate biopsies increase the detection rate of prostate cancer

OBJECTIVES: 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. We developed a novel three-dimensional (3D) computer-assisted prostate biopsy simulator based on whole-mounted step-sectioned radical prostatectomy specimens to compare the diagnostic accuracy of various prostate needle biopsy protocols. METHODS: We obtained digital images of 201 step-sectioned whole-mounted radical prostatectomy specimens. 3D computer simulation software was developed to accurately depict the anatomy of the prostate and all individual tumor foci. Additional peripheral devices were incorporated into the system to perform interactive prostate biopsies. We obtained 18 biopsies of each prostate model to determine the detection rates of various biopsy protocols. RESULTS: The 10- and 12-pattern biopsy protocols had a 99.0% detection rate; the traditional sextant biopsy protocol rate was only 72.6%. The 5-region biopsy protocol had a 90.5% detection rate and the 14-pattern, which includes all the biopsies used in the patterns above, only added 1 additional positive case (99.5%). Transitional zone and seminal vesicle biopsies did not result in a significantly increased detection rate when added to the patterns above. Only one positive model was obtained when the transitional zone biopsies were added. The lateral sextant pattern had a detection rate of 95.5%, and the 4-pattern lateral biopsy protocol had a 93.5% detection rate. CONCLUSIONS: Our results suggest that all the biopsy protocols that use laterally placed biopsies based on the 5-region anatomic model are superior to the routinely used sextant prostate biopsy pattern. Lateral biopsies in the mid and apical zones of the gland are the most important.     

Impact of additional sampling in the TRUS-guided biopsy for the diagnosis of prostate cancer

AIM: To evaluate the diagnostic value of 10+ systematic sampling technique when performing transrectal ultrasound-guided (TRUS) prostate biopsy, compared with the sextant biopsy technique for patients with suspected prostate cancer. METHODS: 286 patients with suspected prostate cancer were included in the study. Patients were eligible for the study if they had serum levels of prostate-specific antigen (PSA) >4 ng/ml or ratio PSA <0.25 and/or an abnormal digital rectal examination (DRE). The population sample was divided in three groups: (1) those with positive PSA, PSA ratio and DRE (70 patients); (2) those with positive PSA and PSA ratio but normal DRE (178 patients), and (3) those with positive PSA and PSA ratio, positive PSA velocity and a negative biopsy in the previous 6-month period (38 patients). In addition to the conventional sextant prostate biopsy cores, four more biopsies were obtained from the lateral peripheral zone (10 core biopsy protocol). Additional cores (total of 12-14) were also randomly selected in case of larger prostates (>60 ml) or from suspicious foci revealed by transrectal ultrasound. All additional biopsy cores were submitted separately to the pathological department. RESULTS: Cancer was detected in 55.7% (39/70) and 69% (48/70) of the patients (for sextant core and for the extended biopsy protocols, respectively) in the first study group, 11% (20/178) and 23% (41/178) of the patients (for the sextant and the extended biopsy protocols, respectively) in the second study group, and 42% (16/38) and 63% (24/38) of the patients (for the sextant and the extended biopsy protocols, respectively) in the third study group. The addition of the lateral peripheral zone (PZ) of the prostate to the sextant biopsy showed a 23, 105 and 50% increase in the number of cancers diagnosed in the first, second and third study groups, respectively. The improvement of cancer detection rate (sensitivity) was statistically significant for all groups evaluated. CONCLUSION: The 10+ systematic TRUS-guided prostate biopsy improves the detection rate of prostate cancer compared to the sextant biopsy technique alone, especially when performed in men with positive PSA, PSA ratio, and negative DRE.     

Differences in biopsy features between prostate cancers located in the transition and peripheral zone

OBJECTIVE: To identify the zonal location of prostate cancers before surgery, by analysing the mapping of ultrasonography-guided systematic sextant biopsies for differences between cancers located in the transition zone (TZ) and peripheral zone (PZ); and to compare the correlation between Gleason scores of needle biopsies and those of radical prostatectomy (RP) specimens. PATIENTS AND METHODS: In all, 186 patients with TZ (46) and PZ cancers (140) underwent ultrasonography-guided systematic sextant biopsy and RP at the same institution. The clinical and pathological characteristics, and the anatomical location of positive biopsies, were determined and compared using t-tests and chi-square tests. Differences between Gleason scores of needle biopsies and those of RP specimens were evaluated and compared by Cohen kappa testing. RESULTS: TZ cancers had a significantly lower rate of positive biopsies in the middle (63% vs 80%) and base (50% vs 80%) of the prostate than had PZ cancers. Positive biopsies were exclusively obtained from the apex in 19.6% of TZ and 5% of PZ cancers (P = 0.002). There was exact agreement between Gleason scores of needle biopsies and those of RP specimens in 15.2% of TZ (kappa = 0.02) and 55% of PZ cancers (kappa = 0.25), respectively. CONCLUSION: Compared with PZ cancers, TZ cancers had a different anatomical pattern of positive biopsies, with lower rates in the middle and base of the prostate. The finding of positive biopsies exclusively in the apex favoured prostate cancer located in the TZ. Furthermore, the correlation between needle biopsy Gleason scores and those of the RP specimens was clearly lower in TZ cancers.     

Transition zone biopsy in the detection of prostate cancer

OBJECTIVE: About 25% of all prostate cancers occur in the transition zone (TZ). We analyzed the impact of 4 systematic TZ and 2 systematic apex (AP) biopsies in addition to systematic sextant biopsies in an effort to establish the diagnostic importance of early prostate cancer. METHODS: One hundred and thirty patients underwent systematic transperineal multipoint prostate biopsy (biopsy of 12 sites, including 4 TZ and 2 AP biopsies). RESULTS: Forty-one of 130 men (31.5%) had biopsy specimens positive for cancer, and cancer originated in the TZ alone in 4 of these 41 patients (9.8%). Fourteen patients underwent radical retropubic prostatectomy. We compare the pathological findings of radical prostatectomy specimens and biopsy results. Prostate cancers predicted to be stage T(2c) by TZ biopsy were all classified as pT(2c) or greater. CONCLUSIONS: Routine TZ biopsy does not substantially increase the prostate cancer detection rate; however, it can be useful in patients who require repeat biopsy.     

Biopsies of the transitional zone of the prostate. Should it be done on a routine basis, when and why?

PURPOSE: In this prospective study we try to evaluate the necessity of performing additional transitional zone biopsies as part of the standard sextant biopsies procedure in order to detect prostate cancer. MATERIALS AND METHODS: During a 12-month period we performed biopsies in 420 patients. All patients had two additional biopsies of the transitional zone biopsies. 289 of them were biopsies for the first time because they had an elevated PSA and/or a suspicious DRE. One hundred and thirty-one had a repeat biopsy because of the remaining elevated PSA after the previous negative one. RESULTS: Of the 420 patients 143 (34%) had cancer, with 11 (7%) having cancer in the transitional zone only. Patients initially evaluated because of high PSA and or a positive DRE had only 2 (2.1%) cancers exclusively in the transitional zone. We found that this percentage rises (18.7%) when the patients had already at least one previous negative biopsy of the peripheral zone, and during the repeat biopsy the transitional zone is samples. CONCLUSIONS: The low yield of transitional zone biopsies (2.1%) during first time sampling of the prostate does not warrant their systematic use for the early detection of prostate cancer. Instead the effectiveness of biopsies in that area is higher when the biopsy is repeated after an initial previous negative biopsy of the peripheral zone.     

Significance of routine transition zone biopsies in Japanese men undergoing transrectal ultrasound-guided prostate biopsies

BACKGROUND: The objective of this study was to evaluate the clinical significance of additional routine transition zone (TZ) biopsies in Japanese men undergoing transrectal ultrasound (TRUS)-guided systematic 8-core peripheral zone (PZ) biopsies. METHODS: Between October 2002 and December 2004, a total of 788 consecutive patients underwent TRUS-guided systematic biopsy of the prostate for the fi rst time. As a rule, 10 cores were taken from each patient; that is, 8 cores from the PZ, including the standard sextant cores and 2 cores from the anterior lateral horns, and 2 additional cores from the bilateral TZ. The cancer detection rate was calculated according to several parameters. We also assessed the disease extent on radical prostatectomy specimens according to the cancer location within the biopsy specimens. RESULTS: Prostate cancer was detected by 10-core biopsies in 209 (26.5%) of the 788 patients, and 11 of these patients had positive cores only in the TZ; that is, the increase in cancer detection rate by sampling two additional cores from the TZ was 5.3%. Among 209 patients diagnosed as having prostate cancer, radical prostatectomy without any neoadjuvant therapy was performed in 59 patients with positive biopsy cores in the PZ, 7 in the TZ and 32 in both the PZ and TZ. Patients with positive cores in both zones showed significantly less favorable characteristics, indicating more advanced disease than that in those with positive cores in either zone. CONCLUSIONS: Routine TZ biopsy did not significantly increase the detection rate of prostate cancer; however, the anatomical location of positive biopsy cores could provide additional information concerning disease extension in patients undergoing radical prostatectomy.     

Significance of lateral biopsy specimens during transrectal ultrasound-guided prostate biopsies in Japanese men

OBJECTIVES: Lateral biopsies are thought to have a better cancer detection rate compared with standard sextant biopsies. This study aimed to determine whether lateral peripheral zone biopsies in Japanese men who underwent transrectal ultrasound-guided prostate biopsies provided a significantly higher cancer detection rate than sextant biopsies. METHODS: Between 1999 and 2004, data were collected from 461 men who underwent prostate biopsy and had enough data regarding the performance of lateral biopsies for statistical analysis. There were two categories in this study: (i) patients who underwent sextant prostate biopsies; and (ii) patients who underwent sextant biopsies plus lateral biopsies. RESULTS: Prostate cancer was detected in 141 (30.6%) of 461 patients. It was detected in 24 (22.2%) of 108 patients who underwent sextant biopsies and 117 (33.1%) of 353 patients who underwent sextant plus lateral biopsies. Lateral biopsies were not associated with a statistically higher rate of positive biopsy findings; however, we found a significantly higher ratio of patients with positive findings in those with prostate specific antigen (PSA) levels 10 ng/mL (one of 71, 1.4%) among those who had positive cores only in lateral biopsy samples (P < 0.0001). CONCLUSIONS: Lateral biopsies did not show a significantly higher detection ratio of prostate cancer compared to sextant biopsies. However, lateral biopsies were more effective than sextant biopsies in patients with lower PSA levels. Our findings might be useful for the establishment of biopsy strategies to detect prostate cancer, especially in patients with lower PSA levels.     

Does transurethral resection of the prostate facilitate detection of clinically significant prostate cancer that is missed with systematic sextant and transition zone biopsies?

BACKGROUND: A prospective study was conducted to determine whether transurethral resection of the prostate (TURP) facilitates detection of prostate cancer that is missed with systematic sextant biopsies associated with transition zone (TZ) biopsies. METHODS: A total of 139 consecutive patients underwent transperineal TZ biopsies of each lobe in addition to a transrectal systematic sextant peripheral zone (PZ) biopsy. Patients whose biopsies were negative for cancer received TURP for relief of lower urinary tract obstruction when indicated. RESULTS: Cancer was detected in biopsy specimens of 40 patients. Of these cancers, 18 originated in the PZ alone and 22 were located both in the TZ and the PZ. No cancers were detected in the TZ alone. Of 99 patients who were proven not to have cancer by the biopsies, 18 were indicated for TURP. Five of these patients (28%) had cancer in the resected tissues. All cancers were clinically organ confined and their Gleason sum scores were 2-5. Cancer-positive chips accounted for less than 10% of all resected specimens. Of the 66 patients with negative biopsies and without indication for TURP, four (6%) were revealed to have an elevation of the serum PSA level during follow up. They were later proven to have cancer by a second biopsy. CONCLUSION: Routine use of TZ biopsy is not warranted for detection of cancer. Transurethral resection of the prostate can detect cancers in patients with negative PZ and TZ biopsies. However, cancers detected by TURP may not always be clinically significant and only four of 66 patients who were not indicated for TURP and received a close follow up were later found to have cancer, although their follow-up period was short. Thus, it still remains to be elucidated whether TURP is necessary for all patients with negative biopsies of the prostate.     

Value of Systematic Transition Zone Biopsy in the Detection of Prostate Cancer

Background:
We evaluated routine transition zone biopsies for the detection of prostate cancer.
Methods:
Systematic sextant transrectal biopsies, including 2 systematic transition zone biopsies (sextant biopsy group), were performed on 196 consecutive patients. Biopsies were based on indications from digital rectal examination and/or a serum PSA level greater than 4.0 ng/ml. During the same period, 21 patients with persistently elevated PSA levels and earlier negative systematic biopsies also had the sextant biopsy (re-biopsy group). The sextant biopsy group was compared with 1 24 cases in our previous cancer detection program who had systematic quadrant biopsies targeted to the peripheral zone (quadrant biopsy group).
Results:
Between the sextant and quadrant biopsy groups, the difference in rate of cancer detection was not significant statistically. Of the sextant biopsy group, 64 (33%) demonstrated malignancy, including 9 (4.6%) with cancer found exclusively in the peripheral zone and 55 (28%) both in the peripheral and transition zones. No cancer was found exclusively in the transition zone. Of the re-biopsy group, all 4 cancers (19%) were detected in the transition zone, 2 of them exclusively in the transition zone.
Conclusion:
Routine transition zone biopsies did not increase the detection rate of prostate cancer. Systematic transition zone biopsies proved useful to the patients with persistently elevated PSA values and negative results in previous systematic peripheral zone biopsies.     

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.     

Importance of posterolateral needle biopsies in the detection of prostate cancer

Objectives. To determine whether needle biopsy of the posterolateral aspects of the prostate aids in prostate cancer detection. In the routine sextant biopsy strategy, the posterolateral aspects of the prostate are not sampled.Methods. Using an 18-gauge biopsy gun, we performed sextant biopsies and an additional nine needle biopsies in the pathology laboratory on 150 radical prostatectomy specimens performed for Stage T1c prostate cancer. The additional nine biopsies consisted of three midline biopsies and six (three each from the left and right) posterolaterally aimed biopsies from the apex, mid, and base regions of the gland. Significant tumors were defined as those greater than 0.5 cm³, or with a Gleason score of 7 or greater, or non-organ confined.Results. Of the 123 cases with cancer on repeated biopsy, in only 3 (2.4%) was the only cancer found in the midline biopsies. For the following analysis, we analyzed the data as if we had not done the midline biopsies. If one had performed only the routine sextant needle biopsies, in 31 (25.2%) of the 123 cases, tumor would have been missed; 20 of these tumors were significant, including 5 with extraprostatic extension. If one had performed only the more posterolateral six biopsies, in 15 cases (12.2%), tumor would have been missed; 5 of these tumors were significant, all of which were organ confined.Conclusions. Adding routine midline biopsies does not appreciably increase the detection of cancer. If one were to only perform six needle biopsies of the prostate, these biopsies should be aimed more toward the posterolateral aspect of the gland. Maximum cancer detection results from combining both routine sextant and posterolateral needle biopsies.     

OPTIMIZATION OF PROSTATE BIOPSY STRATEGY USING COMPUTER BASED ANALYSIS

Purpose

We evaluated and optimized the detection of cancer by prostate biopsies. We developed a stochastic computer simulation model of ultrasound guided biopsies using mathematically reconstructed radical prostatectomy specimens. Use of this technique allows rapid evaluation of a variety of factors for their effect on prostate biopsy results. We used this model analyze the effectiveness of sextant biopsies, which have been widely adopted in clinical practice. We also analyzed other biopsy schemes.

Materials and Methods

A total of 607 tumor foci from 180 serially sectioned whole mount radical prostatectomy specimens was mapped and digitized. The cancers had been clinically diagnosed by a variety of biopsy strategies. Simulated parasagittal sextant biopsies were performed for each case. Forty simulation runs (each consisting of a set of 6 biopsies) were performed for each prostate, with realistic random variations in sextant biopsy localization programmed in each run. Cancer detection by biopsy was considered reliable if 90% of the stimulation runs for each prostate were positive for cancer. A summary algorithm was used to map the tumor foci.

Results

Simulation of sextant biopsies demonstrated reliably detected cancer in only 107 of 147 patients (73%) in whom total tumor volume was greater than 0.5 cc. There was little correlation between total length of cancer in biopsy cores and tumor volume. Change of biopsy angle from 30 to 45 degrees did not result in significantly increased detection rates. Similarly, placing all biopsies more laterally did not increase overall detection rates. When we mapped tumor foci from the 40 cases in which sextant biopsies did not reliably detect tumor, we found that the foci were distributed in areas not biopsied by the sextant method, that is the transition zone, midline peripheral zone and inferior portion of the anterior horn of the peripheral zone. A 10-core biopsy scheme incorporating these areas as well as the posterolateral prostate reliably detected cancer in 141 of 147 patients (96%) with total tumor volumes greater than 0.5 cc.

Conclusions

Prostate cancer of significant volume can be present in areas not sampled by standard sextant biopsies. Biopsies of the transition zone, midline peripheral zone and inferior portion of the anterior horn of the peripheral zone should be considered for re-biopsy strategy after negative sextant biopsies. Sampling of these additional areas also can be incorporated in an initial biopsy scheme to increase overall initial rates of detection of prostate cancer.     

A comparative analysis of sextant and an extended 11-core multisite directed biopsy strategy

PURPOSE: The 3 tumor locations unsampled by conventional sextant biopsies that have been identified on composite 3-dimensional reconstruction of 180 radical prostatectomy specimens are the anterior transition zone, midline peripheral zone and inferior portions of the anterior horn in the peripheral zone. We evaluated an 11-core multisite directed biopsy scheme incorporating these alternate areas and conventional sextant biopsies in 362 patients from 2 institutions. MATERIALS AND METHODS: Patients without a prior diagnosis of cancer underwent ultrasound guided 11-core biopsies which included conventional sextant and 3 alternate sites. All specimens were separated for specific location identification. Biopsy was performed in 183 patients at MD Anderson Cancer Center (group 1) and in 179 at Toronto General Hospital (group 2). All group 2 and 54% of group 1 patients (98 of 183) had a prior biopsy negative for cancer. RESULTS: Median prostate specific antigen was higher in group 2 than in group 1 patients (11.5 versus 9.5 ng./ml., p = 0.016). Overall a 33% increase (36 of 110 patients) in cancer detection was observed when biopsy technique included the alternate areas (p = 0.0021). The anterior horn was the most frequently positive biopsy site followed by the transition zone and midline sites. The 11-core technique had significantly better cancer detection rates when digital rectal examination and transrectal ultrasound were normal, and in men with serum prostate specific antigen between 4.1 and 10 ng./ml. CONCLUSIONS: Biopsies of the alternate sites suggested by our simulation studies are feasible and reproducible. This new strategy significantly enhanced (p = 0.0075) prostate cancer detection compared to conventional sextant biopsies in men undergoing a repeat procedure.     

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.