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.     

Six additional systematic lateral cores enhance sextant biopsy prediction of pathological features at radical prostatectomy

PURPOSE: We evaluated the contribution of 6 additional systematically obtained, laterally directed biopsy cores to traditional sextant biopsy for the prediction of final pathological findings in the radical prostatectomy specimen. MATERIALS AND METHODS: We studied 178 consecutive patients with no history of prostate biopsy in whom prostate cancer was diagnosed during an initial systematic 12 core biopsy and who subsequently underwent radical prostatectomy. Of the systematic 12 cores we compared the subset of the 6 traditional sextant cores (S6C), the set of 6 laterally directed cores (L6C) and the complete 12 core set, which included the 6 traditional sextant and the 6 laterally directed cores. Biopsy Gleason score, number of positive cores, total cancer length and percent of tumor in the biopsy sets were examined for their ability to predict extracapsular extension, total tumor volume and pathological Gleason score. RESULTS: On univariable analyses the biopsy parameters of the complete 12 core set correlated more strongly with extracapsular extension and total tumor volume than the biopsy parameters of S6C or L6C. On multivariable analyses S6C and L6C were independent predictors of pathological features at prostatectomy. CONCLUSIONS: The addition of 6 systematically obtained, laterally directed cores to traditional sextant biopsy improved the ability to predict pathological features at prostatectomy by a statistically and prognostically significant margin. Preoperative nomograms that use data from a full complement of 12 systematic cores, specifying sextant and laterally directed biopsy cores, should demonstrate improved performance in predicting prostatectomy pathology.     

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.     

Importance of peripheral biopsies in maximising the detection of early prostate cancer in repeat 12-core biopsy protocols

OBJECTIVE: To assess cancer-detection rates in repeat 12-core biopsy protocols, as extended multicore prostate biopsy protocols have become standard when investigating men with a raised prostate-specific antigen (PSA) level, but repeat prostate biopsy protocols are still developing. PATIENTS AND METHODS: During a 4.5-year period, 241 of 590 patients with persistently high age-specific PSA levels of 2.6-10 ng/mL and an initial benign biopsy were invited for repeat transrectal ultrasonography-guided 12-core prostatic biopsy. The protocol for repeat biopsy was identical to the first biopsy, and included a periprostatic nerve block. The first six biopsies were obtained from the periphery of the gland directed more laterally at the base, mid-zone and apices. The remainder were parasagittal sextant biopsies. Pathological findings were analysed on an individual core basis. RESULTS: The mean age of the 241 men was 63.4 years; cancer was diagnosed in 40 (16.6%) on repeat biopsy. Men with cancer were older and had a higher median PSA level. The median Gleason score was 6, with a median of two cores positive for cancer. Maximum cancer detection rates were from peripheral apices (37.5%), basal biopsies had the lowest detection rates (23.8% and 16.3%), and parasagittal biopsies missed 35% of detected cancers. Patients with cancer also had significantly lower prostate volumes and higher PSA densities (both P < 0.001). CONCLUSION: A low cancer yield from both peripheral basal and parasagittal basal specimens on repeat biopsy indicates adequate sampling at initial biopsy. The maximum cancer yield in the peripheral mid-zones and apical zones suggests the necessity for concentrated sampling of these zones in repeat biopsy protocols.     

Probability of prostate cancer detection based on results of a multicenter study using the AxSYM free PSA and total PSA assays

OBJECTIVES: The determination of the percentage of free prostate-specific antigen (%fPSA) enhances the specificity of prostate cancer (CaP) detection. This study was undertaken to assess the performance of %fPSA in differentiating benign prostate disease from CaP and to determine the CaP probability estimates using the AxSYM Free PSA and AxSYM Total PSA assays. METHODS: In this prospective study, 297 men, 50 years old or older, with a total PSA level between 4 and 10 ng/mL and a nonsuspicious digital rectal examination were enrolled at 10 clinical sites. All subjects underwent at least sextant prostate biopsies to establish the diagnosis. fPSA and total PSA (tPSA) levels were determined using the AxSYM Free PSA and AxSYM Total PSA assays. Percent fPSA values were compared with tPSA values to determine the appropriate cutoffs for prostate biopsy and to calculate the CaP probability estimates. RESULTS: The strongest predictor of CaP in a logistic regression model was %fPSA (odds ratio 2.29), which contributed significantly more than age or tPSA to the predictive model. In this study population, a %fPSA cutoff of 26.4% would have detected 96% of subjects with CaP (sensitivity) and would have eliminated 27.4% of unnecessary biopsies (specificity). CaP probability estimates ranged from 9% to 69% and increased as the %fPSA value decreased. Men with a %fPSA level of 10% or lower had a 69% probability of CaP, and men with a %fPSA level of greater than 26% had a 9% probability of CaP. CONCLUSIONS: Percent fPSA values can help differentiate CaP from benign prostate disease and reduce unnecessary biopsies in 27% of men 50 years old or older whose digital rectal examination was normal and whose tPSA level was between 4 and 10 ng/mL. A %fPSA result can assist the physician and patient in determining the probability of CaP and assessing the need for prostate biopsy.     

Diagnostic value of systematic biopsy methods in the investigation of prostate cancer: a systematic review

PURPOSE: Several new extended prostate biopsy schemes (greater than 6 cores) have been proposed. We compared the cancer detection rates and complications of different extended prostate biopsy schemes for diagnostic evaluation in men scheduled for biopsy to identify the optimal scheme. MATERIALS AND METHODS: In a systematic review we searched 13 electronic databases, screened relevant urological journals and the reference lists of included studies, and contacted experts. We included studies that compared different systematic prostate biopsy methods using sequential sampling or a randomized design in men scheduled for biopsy due to suspected prostate cancer. We pooled data using a random effects model when appropriate. RESULTS: We analyzed 87 studies with a total of 20,698 patients. We pooled data from 68 studies comparing a total of 94 extended schemes with the standard sextant scheme. An increasing number of cores were significantly associated with the cancer yield. Laterally directed cores increased the yield significantly (p = 0.003), whereas centrally directed cores did not. Schemes with 12 cores that took additional laterally directed cores detected 31% more cancers (95% CI 25 to 37) than the sextant scheme. Schemes with 18 to 24 cores did not detect significantly more cancers. Adverse events for schemes up to 12 cores were similar to those for the sextant pattern. Adverse event reporting was poor for schemes with 18 to 24 cores. CONCLUSIONS: Prostate biopsy schemes consisting of 12 cores that add laterally directed cores to the standard sextant scheme strike the balance between the cancer detection rate and adverse events. Taking more than 12 cores added no significant benefit.     

Predictors of prostate cancer on repeat prostatic biopsy in men with serum total prostate-specific antigen between 4.1 and 10 ng/mL

OBJECTIVES: We determine whether the different molecular forms of prostate-specific antigen (PSA) and other PSA variables can predict prostate cancer in men undergoing repeat prostate needle biopsy. METHODS: Between 1997 and 2001, repeat biopsy was performed in 97 patients who had undergone prior negative prostate biopsy. The ability of total PSA (tPSA), complexed PSA (cPSA), free PSA (fPSA), free-to-total PSA (fPSA/tPSA), free-to-complexed PSA (fPSA/cPSA), complexed-to-total PSA (cPSA/tPSA), tPSA density (tPSAD), cPSA density (cPSAD), transition zone tPSA density (tPSATZ) and transition zone cPSA density (cPSATZ) was assessed by univariate and multivariate analyzes as well as receiver operating characteristics (ROC) curves. RESULTS: Prostate cancer on repeat biopsy was detected in 24% of subjects (23 of 97) who had a negative initial biopsy. The PSA parameters cut-off to ensure a 96% sensitivity of cancer detection, were 29% using fPSA/tPSA, 32% using fPSA/cPSA, 0.18 ng/mL/cc using tPSATZ and 0.16 ng/mL/cc using cPSATZ. The fPSA/tPSA would have prevented 32% of negative biopsies, the fPSA/cPSA 28%, the tPSATZ 23% and the cPSATZ 30%. ROC curve analysis fPSA/tPSA, fPSA/cPSA ratios, tPSATZ and cPSATZ were significantly better predictors of repeat biopsy results than tPSA or cPSA, but there was no significant difference in the ROC curves among these four PSA parameters. In the multivariate logistic regression analysis these four PSA parameters were significant predictors for cancer detection in the repeat biopsy group (P < 0.001). CONCLUSION: fPSA/tPSA ratio, fPSA/cPSA ratio, tPSATZ and cPSATZ enhance the specificity of PSA testing compared to tPSA or cPSA when determining which patients should undergo repeat biopsy.     

Performance of a neural network in detecting prostate cancer in the prostate-specific antigen reflex range of 2.5 to 4.0 ng/mL

Objectives. To explore the potential role of a neural network-derived algorithm in enhancing the specificity of prostate cancer detection compared with the determination of prostate-specific antigen (PSA) and free PSA (fPSA) while maintaining a 90% detection rate. Recent information suggests that the incidence of detectable prostate cancer is similar in men whose PSA values range from 2.5 to 4.0 ng/mL and from 4.0 to 10.0 ng/mL. If the PSA threshold triggering a prostate biopsy is lowered to 2.5 ng/mL, approximately 13% of men older than 50 would be added to the patient biopsy pool.Methods. One hundred fifty-one men were enrolled in a prospective, Institutional Review Board-approved protocol to evaluate the incidence of cancer in a population of men who participated in an early-detection program and whose PSA level was between 2.5 and 4.0 ng/mL. All the men underwent biopsy using an 11-core multisite-directed biopsy scheme, and all biopsy specimens were examined by one pathologist. All men had a second blood specimen drawn before the biopsy for a determination of serum PSA, creatinine kinase, prostatic acid phosphatase, and fPSA. A new neural network algorithm was developed with PSA, creatinine kinase, prostatic acid phosphatase, fPSA, and age as input variables to produce a single-valued prostate cancer detection index (PCD-I). This new algorithm was then prospectively tested in the 151 men. Performance parameters (including sensitivity, specificity, positive and negative predictive values, and biopsies saved) were calculated, and a comparative analysis was performed to evaluate the differences among the new algorithm, percent fPSA, PSA density, and PSA density-transition zone.Results. Cancer was histologically confirmed in 24.5% (37 of 151) of the men. The median age of the men was 62 years (range 43 to 74). At a sensitivity of 92%, the specificity for percent fPSA was 11%. The new algorithm (PCD-I) demonstrated an additional enhancement of specificity to 62% at 92% sensitivity. Clinically, the PCD-I would result in a savings of 49% (74 of 151) of all biopsies or 63.6% (71 of 114) of all unnecessary biopsies.Conclusions. A new generation algorithm, derived from a neural network (PCD-I) incorporating the parameters of age, creatinine kinase, PSA, prostatic acid phosphatase, and fPSA can significantly enhance the specificity and reduce the number of biopsies while maintaining a 92% sensitivity rate.     

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     

Association of free PSA percent, total PSA, age, and gland volume in the detection of prostate cancer.

BACKGROUND: Measurement of the free fraction of total prostate-specific antigen (fPSA%) has been proposed as a useful addition to total PSA for the detection of prostate cancer. METHODS: We assessed the performance of fPSA% in differentiating men with prostate cancer from men without cancer in a group of 1,709 subjects studied in five institutions. RESULTS: On the basis of PSA testing, digital rectal examination, and ultrasound examination conducted at one or more visits, 229 cancers were diagnosed. The mean fPSA% in men with cancer was 9.1% compared to 18.9% in men without cancer. The fPSA% varied by age, with men under 60 having a mean fPSA of 13.9% compared to 17.5% in men 60-69 years old and 19.8% in men over age 70. Significant associations of fPSA% with gland volume and PSA level were also observed. The sensitivity, specificity, and positive predictive value of different fPSA% cutoff levels were assessed in 513 men who underwent sextant biopsy. Sensitivity of 85.4%, 32.1% specificity, and a 39.2% positive predictive value were observed using an fPSA cutoff of 15% in men with PSA in the 4.0-9.9 ng/ml range. Sensitivity of 96.9%, 12.3% specificity, and a 36.2% positive predictive value were observed using an fPSA cutoff of 20% in the same men. If 15% fPSA had been used as a biopsy criterion in men with PSA of 4.0-9.9 ng/ml, the number of biopsies performed could have been reduced by 21.2%, with a concomitant reduction in cancer detection of 14.6%. Using a 20% fPSA criterion, biopsies would have been reduced 12.7%, with a 3.1% reduction in cancer detection. CONCLUSIONS: These results provide some evidence that the detection of prostate cancer is enhanced by measuring fPSA% in addition to the established measure of total PSA level. Further research is needed to identify other markers that have better sensitivity and specificity.     

Extended peripheral zone biopsy schemes increase cancer detection rates and minimize variance in prostate specific antigen and age related cancer rates: results of a community multi-practice study

PURPOSE: We assessed the impact of age and prostate specific antigen (PSA) on extended systematic biopsy schemes for detecting prostate carcinoma and better characterized these tumors as a function of patient age and PSA. MATERIALS AND METHODS: We retrospectively reviewed the records of 2,299 consecutive patients who underwent initial systematic biopsy performed by 167 community based urologists. A total of 12 systematic biopsies of the peripheral zone were obtained in all patients. Various biopsy schemes were then created and cancer detection rates were calculated. Data analyses were stratified by patient age and PSA. RESULTS: On biopsy 1,020 patients (44.4%) had cancer. Detection rates increased with increasing patient age. Increasing age and PSA were associated with larger, higher grade tumors. Overall and unique site specific cancer detection rates were highest for laterally directed biopsies and the apical biopsy of the standard sextant scheme. The 12 site biopsy scheme outperformed all other schemes in patients with PSA 7 ng./ml. or less and in those 60 years or younger. The variation in age related and PSA related detection rates was greatest for the standard sextant scheme and this variability decreased for extended biopsy schemes. CONCLUSIONS: This multi-practice community based study confirms the inadequacy of sextant biopsies and emphasizes the need for extended peripheral zone sampling of the lateral aspect of the prostate. Generally increasing patient age and PSA were associated with larger, higher grade tumors. Extended biopsy schemes minimize PSA and age related detection rates.     

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.     

Evaluation of proprostate specific antigen for early detection of prostate cancer in men with a total prostate specific antigen range of 4.0 to 10.0 ng/ml

PURPOSE: In contemporary screening populations a major drawback of prostate specific antigen (PSA) is its relative lack of specificity, especially in the range of 4 to 10 ng/ml, where prostate cancer is found 25% of the time. ProPSA is a derivative of free PSA (fPSA) consisting of the truncated forms (eg [-2]proPSA, [-4]proPSA or the full-length [-7]proPSA). There is increasing evidence that proPSA is associated preferentially with prostate cancer. The objective of this study was to determine whether proPSA can influence the detection of early prostate cancer. MATERIALS AND METHODS: Archival serum samples obtained from 93 men who underwent a systematic 12-core prostate biopsy (total PSA range 4.0 to 10.0 ng/ml) were assayed for percent free PSA, total PSA and the 3 forms of proPSA (Hybritech Tandem Assays Beckman Coulter Access, Beckman Coulter, Inc., Brea, California). Free PSA, the cumulative sum of individual proPSA forms ([-2], [-4] and [-7], or sum-proPSA) and derivatives were determined. Of the 93 men assessed 41 (44%) had evidence of prostate cancer (76% Gleason 5/6, 19% Gleason 7 and 5% Gleason 8). Prostate volume was measured at systematic 12-core biopsy for the detection of prostate cancer. Results were analyzed using univariate and multivariate logistic regression (LR) nonparametric statistical methods. RESULTS: Using univariate LR, fPSA, percent fPSA (%fPSA), percent sum-proPSA and prostate volume significantly (p <0.05) differentiated men with prostate cancer from those with benign disease. However, applying stepwise backward multivariate LR, total PSA, %fPSA and sum-proPSA were retained and generated a receiver operator characteristic curve with an area under the curve of 76.6%. At 90% sensitivity these 3 variables collectively achieved a specificity of 44% for the detection of prostate cancer. Individually, the 3 retained variables had a specificity of 23% (total PSA), 33% (%fPSA) and 13% (sum-proPSA). CONCLUSIONS: Sum-proPSA, total PSA and %fPSA in combination improve the specificity of early prostate cancer detection in men with a total PSA of 4 to 10 ng/ml compared with the results of individual PSA molecular forms measured.     

Complexed prostate specific antigen improves specificity for prostate cancer detection: results of a prospective multicenter clinical trial

PURPOSE: Complexed (c) prostate specific antigen (PSA) has been shown to enhance specificity for prostate cancer (CaP) detection over total PSA (tPSA), although a large multi-institutional prospective evaluation was required to confirm these findings. We compared the clinical performance of cPSA with tPSA as a first line test for CaP detection and secondarily to determine if PSA ratios, namely percent free PSA (fPSA) and percent cPSA, can provide further enhancement in diagnostic performance over cPSA or tPSA. MATERIALS AND METHODS: Consecutive men scheduled for initial biopsy of the prostate were enrolled prospectively at each of 7 university centers and community based urology practices. Serum was collected and tested with the Immuno 1 (Bayer Diagnostics, Tarrytown, New York), tPSA and cPSA, and Access (Beckman, Inc., San Diego, California) fPSA and tPSA methods. RESULTS: A total of 831 patients were evaluated, of whom 313 (37.5%) were diagnosed with CaP. ROC curve analysis performed from the results of all samples and those within the clinically relevant cPSA ranges of 1.5 to 3.2, 1.5 to 5.1, 1.5 to 8.3 and 3.2 to 8.3 ng/ml (tPSA 2 to 4, 2 to 6, 2 to 10 and 4 to 10 ng/ml, respectively) indicated a significant improvement in the AUC ROC curve for cPSA compared with tPSA (p < or =0.001). Using cutoff points that provide a sensitivity of 80% to 95% for CaP detection within the 1.5 to 8.3 ng/ml cPSA range cPSA provided a statistically significant enhancement in specificity over tPSA of 6.2% to 7.9%. Within the cPSA range of 1.5 to 3.2 ng/ml using a cutoff point of 2.5 ng/ml for tPSA and 2.2 ng/ml for cPSA provided a specificity of 21.2% and 35%, respectively, and 85% sensitivity for CaP detection. PSA ratios provided no further enhancement in specificity over cPSA within these ranges. CONCLUSIONS: The use of cPSA as a single test provided improved specificity over tPSA. Percent fPSA and percent cPSA offered little to no additional benefit in the differentiation of benign and malignant disease at clinically relevant cPSA concentrations.     

How to improve prostate biopsy detection of prostate cancer

The combination of serum prostate-specific antigen (PSA) testing and transrectal ultrasonography is a highly effective strategy to diagnose prostate cancer at an early curable stage. Even though PSA is the most useful serum biomarker to aid in prostate cancer detection, it has limited specificity: as many as 75% of men who undergo prostate biopsy because of an elevated PSA do not have prostate cancer. Additionally, sextant prostate biopsies miss prostate cancer at least 20% of the time. To reduce the number of false-negative biopsies, many have advocated obtaining 12 or more cores in a single biopsy session. Studies have shown that this practice is safe and can enhance cancer detection modestly. Although it is unlikely that prostate cancer imaging will replace prostate biopsy in the near future, many exciting new imaging technologies should eventually improve targeting of prostate needle biopsy and reduce false-negative biopsies. Some of the most exciting areas include power Doppler sonography, microbubble intravenous ultrasound contrast agents, and magnetic resonance spectroscopy. These functional imaging modalities can assess tumor blood flow and metabolic activity at a cellular level and can detect malignant changes that may not be detected by standard anatomic imaging.     

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.     

Determination of the percentage of free prostate-specific antigen helps to avoid unnecessary biopsies in men with normal rectal examinations and total prostate-specific antigen of 4-10 ng/ml

OBJECTIVE: To assess the usefulness of measuring the percentage of free prostate-specific antigen (PSA) in serum to reduce the number of prostate biopsies in men with serum PSA levels between 4 and 10 ng/ml and benign prostate examinations. MATERIALS AND METHODS: The percentage of free PSA (Immulite((R))) in serum was analyzed prospectively in 180 men with benign digital rectal examinations and total PSA serum levels of between 4 and 10 ng/ml. All patients underwent ultrasound-guided sextant prostatic biopsies. Sensitivity, specificity and positive and negative predictive values were calculated as well as the percent of patients in which biopsies could have been avoided for various cutoff values of the percentage of free PSA as an indicator for biopsy. Influence of age in the determination of cut points was evaluated. RESULTS: Cancer was detected in 22.2% (40/180) of the patients. Mean percentage of free PSA was 13.4% in patients with cancer and 18.9% in patients with benign prostatic hyperplasia (p = 0.001). Using a percentage of free PSA cutoff of 22% or less as a criterion for performing prostatic biopsy would have detected 95% of cancers, avoided 25% of benign biopsies and yielded a positive predictive value of 29% in patients who underwent biopsy. Mean percent of free PSA values increased as mean subject age increased, influencing the calculation of cut points, sensitivity and specificity. Leaving the cut point constant across all age groups will oblige older patients to undergo an increased number of unnecessary biopsies, although allowing for higher sensitivity in younger men. CONCLUSIONS: Measurement of the percentage of free serum PSA improves specificity of prostate cancer detection in patients with elevated total serum PSA levels and benign prostate examinations. Subject age seemed to influence the determination of optimal cut points.     

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.     

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.     

Comparative study of two different TRUS-guided sextant biopsy techniques in detecting prostate cancer in one biopsy session

OBJECTIVE: The aim of this study was to compare a transrectal ultrasound (TRUS)-guided sextant biopsy technique, which puts more emphasis on the apical region of the prostate where most prostate carcinomas (PCs) develop, with the standard sextant biopsy technique. METHODS: A total of 280 patients with suspected PC were included in this analysis. Twelve biopsy cores were obtained from all patients. Six biopsy cores were taken within a lateral parasagittal plane from each lobe at the apex, middle and basis, with an angle of approximately 45 degrees (technique A), and 6 further biopsy cores were taken from the left to the right lateral margin always penetrating the prostate in the apex with the same angle (socalled fan-shaped technique, technique B). Technique A predominantly samples in the sagittal and technique B samples more in the transversal plane with emphasis on the apical region where most PCs develop. The sensitivity in detecting PCs for both techniques was calculated and correlated to the serum prostate-specific antigen (PSA) levels. RESULTS: A total of 72 PCs (25.7%) were diagnosed. We subsequently performed subgroup analysis depending on the serum PSA levels: in patients with a PSA of 10 ng/ml (n = 45) technique A has a PC sensitivity of 93.3% (p = 0.083) and technique B 88.8% (p = 0.023) as compared to our reference standard. The number of positive core biopsies using technique A was superior in 14 cases as compared to 12 with technique B (p = 0.154). In 19 patients the number of positive biopsies was identical. CONCLUSION: Our data suggest that in patients with PSA of 相似文献