Diagnostic dilemmas in detection of prostate cancer in patients undergoing transrectal ultrasound-guided needle biopsy of the prostate

Transrectal ultrasound (TRUS)-guided needle biopsy of the prostate is a widely practised method for obtaining high quality tissue cores for histological diagnosis in men with suspected prostate cancer. Technological advances such as high-resolution hand held probes with biplanar imaging capabilities and spring-loaded needles that easily permit multiple biopsies to be obtained have ensured that this technique has rightly taken its place at the forefront of prostate cancer diagnosis. However, the capacity for TRUS to identify prostate cancer remains limited because of poor specificity and variability in the ultrasonic appearance of tumours. Widespread prostate-specific antigen (PSA) testing has increasingly resulted in greater numbers of tumours being diagnosed at an early stage, when they are clinically impalpable and ultrasonically indistinguishable from surrounding normal prostate tissue. In this setting, the principal role for TRUS is to facilitate systematic sampling of all relevant zones of the prostate. Despite advances in technology and in our understanding of this disease, a number of diagnostic dilemmas arise. Should we perform lesion-directed or random biopsies? How many tissue cores should be obtained for optimal diagnostic yield, to reduce the incidence of false-negative biopsies? What areas of the prostate should be biopsied to give the best diagnostic results? If the initial biopsies fail to detect cancer, who should undergo repeat biopsy? Some have also voiced concern that TRUS risks identifying clinically insignificant disease. Here, we review the studies that have addressed these issues and have lead to the evolution of TRUS-guided prostate biopsy into an essential tool in the detection of carcinoma of the prostate. Prostate Cancer and Prostatic Diseases (2000) 3, 13-20     

Transrectal power Doppler imaging in the detection of prostate cancer

OBJECTIVES: To evaluate the clinical utility of transrectal power Doppler imaging (PDI) of the prostate for detecting prostate cancer in patients with abnormally high serum levels of prostate specific antigen (PSA). PATIENTS AND METHODS: Patients (107) with abnormally high serum PSA levels were assessed using a digital rectal examination (DRE), transrectal ultrasonography (TRUS) and PDI. Any hypervascular lesion on PDI was graded on a scale of 0-3, where grade 1-3 was considered positive and grade 0 negative. Patients were then diagnosed by prostatic needle biopsy and the results compared with the other detection methods. RESULTS: Needle biopsy confirmed prostate cancer in 41 (24%) of the 170 patients. PDI was positive in 68, of whom 40 (59%) had prostate cancer; all those but one having prostate cancer were positive on PDI. Thus, PDI had a high sensitivity of 98% (40/41) and a negative predictive value of 99% (101/102). PDI could have saved a significant number of patients from undergoing unnecessary biopsies, compared with DRE and TRUS (P < 0.001). CONCLUSION: The use of PDI in detecting prostate cancer might reduce the number of unnecessary needle biopsies of the prostate in patients with abnormally high serum PSA levels.     

常规临床检查与PSA灰区患者前列腺癌检出率的关系

目的:探讨直肠指检(DRE)、影像学(TRUS、MRI)检查、血清游离与总前列腺特异性抗原(PSA)比值(f/t)与PSA在4～10μg/L之间患者前列腺癌检出率的关系。方法:回顾性分析365例PSA处于灰区的患者进行DRE、TRUS、MRI检查、游离PSA测定,并对这些患者行经直肠B超引导下的前列腺穿刺活检。评估其临床资料与前列腺穿刺病理结果的关系。结果:在365例患者中,穿刺病理为前列腺癌的患者共有87例(23.84%)。DRE阳性的患者共有128例,穿刺阳性40例,阳性率为31.25%,TRUS检查的患者共有257例,其中有异常回声结节的69例患者中穿刺阳性26例,阳性率为37.68%,MRI检查的患者共有191例,其中有异常信号结节的107例患者中穿刺阳性59例,阳性率为55.14%。198例患者行fPSA与tPSA比值分析,其中前列腺癌患者的平均f/t PSA明显低于穿刺阴性患者。f/t PSA受试者曲线(ROC)下的面积(0.725)高于患者PSA ROC的面积(0.542)。结论:结合临床DRE、影像学资料及f/t PSA比值可以有效提高前列腺癌检出率,从而减少不必要的穿刺给患者带来的痛苦。     

Predictors of prostate cancer on repeat transrectal ultrasound-guided systematic prostate biopsy

BACKGROUND: We analyzed the outcome of repeated transrectal ultrasound (TRUS)-guided systematic prostate biopsy in Japanese men whose clinical findings were suspected of prostate cancer after previous negative biopsies. METHODS: Between January 1993 and March 2002, 1045 patients underwent TRUS-guided prostate biopsy. Among them, 104 patients underwent repeat biopsy due to indications of persistent elevated serum prostate-specific antigen (PSA), abnormal digital rectal examination (DRE) or TRUS, increased PSA velocity, and/or previous suspicious biopsy findings. Several clinicopathological factors were evaluated for their ability to predict the detection of prostate cancer on repeat biopsy. RESULTS: Prostate cancer was detected in 22 of 104 patients (21.2%) who underwent repeat biopsies. PSA concentration and PSA density at both the initial and repeat biopsies, and PSA velocity in men with positive repeat biopsy were significantly greater than those in men with negative repeat biopsy. The incidence of abnormal findings in DRE and TRUS at initial biopsy in men with positive repeat biopsy was also significantly higher than that in men with negative repeat biopsy. However, neither the presence of prostatic intraepithelial neoplasia nor number of biopsy cores at initial biopsy had a significant association with the results of the repeat biopsy. Furthermore, multivariate analysis revealed that PSA and PSA density at both the initial and repeat biopsies, PSA velocity, and DRE and TRUS findings at initial biopsy were independent predictors of malignant disease on repeat biopsy. CONCLUSION: Despite an initial negative biopsy, repeat TRUS-guided biopsy should be carried out to exclude prostate cancer in cases of suspicious clinical findings, such as elevated PSA or PSA-related parameters, or abnormal findings of DRE or TRUS.     

Effectiveness of percent free prostate specific antigen as a predictor of prostate cancer detection on repeat biopsy

BACKGROUND: The aim of this study was to identify predictors that can increase the accuracy of detecting prostate cancer on subsequent biopsies. METHODS: Between 1998 and 2003, a total of 235 men with prostate specific antigen (PSA) levels between 4.0 and 20 ng/mL underwent one or more systematic needle biopsies of the prostate. Of these men, 73 (31.1%) underwent one repeat biopsy and 26 (11.1%) underwent two or more repeat biopsies. We evaluated the results of prostate biopsies in relation to the morbidity of prostate cancer detected on repeat biopsies. RESULTS: Of the 73 men who underwent repeat biopsy, 16 (21.9%) had prostate cancer. Twenty-six men with one negative re-biopsy underwent two or more repeat biopsies, and five of these patients were found to have early stage prostate cancer. On repeat biopsy, there was a significant difference in percent free PSA between the cancer-detected group and the no-cancer-detected group (P < 0.01). A receiver operating characteristics (ROC) curve gave an optimal cut-off value for percent free PSA of 11%, demonstrating a significant difference in the cancer detection rate on repeat biopsy (P = 0.0009). Analysis of the data for re-biopsies showed that cancer-detected cases showed a raised PSA value and a simultaneously reduced percent free PSA (these differences were statistically significant). CONCLUSIONS: A low percent free PSA level increased the probability of a positive result in repeat biopsy. An increase in the accuracy of detecting cancer, especially on repeat biopsy, will promote the detection of more early stage prostate cancer.     

The role of free prostate-specific antigen in prostate cancer detection

Prostate-specific antigen (PSA) is the most important serum tumor marker for prostate cancer detection. Free PSA is one of the many molecular forms of PSA that have been identified. Percent free PSA improves the specificity (elimination of unnecessary biopsies) for prostate cancer detection in men with nonsuspicious digital prostate examination and total serum PSA ranges between 4 and 10 ng/ mL. Further study is necessary to determine the optimal clinical utility of percent free PSA in men with a total serum PSA level of less than 4 ng/mL. In addition, the level of free PSA may be affected by many factors, including age, prostate volume, prostate manipulation, sample handling, and type of assay used.     

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.     

Importance of transition zone biopsies in patients undergoing ultrasound-guided prostate systemic biopsies for the first time

INTRODUCTION: We analyze the efficacy of routine transition zone biopsies in patients undergoing ultrasound-guided systemic prostate biopsies for the first time because of a suspicious digital rectal examination or an elevated serum prostate-specific antigen (PSA) level. PATIENTS AND METHODS: During systemic prostate biopsy two or four additional transition zone biopsies were performed in 192 consecutive patients: in 182 because of a serum PSA concentration >4.1 ng/ml and in 10 because of a suspicious digital rectal examination and a serum PSA level <4.0 ng/ml. RESULTS: The overall prostate cancer detection rate was 37.5% (72/192). In 24 patients (33.3%), cancer was only detected in the peripheral zone, in 3 (4.2%) only in the transition zone, and in 45 (62.5%) in both zones. CONCLUSION: Transition zone biopsies performed at the first time of systemic prostate biopsy seem to have a low efficacy.     

Importance of transition zone prostate biopsies in patients with gray-zone PSA levels undergoing the ultrasound-guided systematic ten-biopsy regimen for the first time

INTRODUCTION: We analyzed the efficacy of routine transition zone biopsies for patients undergoing ultrasound-guided systematic prostate biopsies for the first time because of an elevated serum prostate-specific antigen (PSA) level. PATIENTS AND METHODS: Using the systematic ten-biopsy regime, four additional transition zone biopsies were performed in 236 consecutive patients, because they showed an elevated PSA level (range 4.0- 9.9 ng/ml). RESULTS: The overall prostate cancer detection rate was 21.2% (50/236). In 24 patients (48.0%), cancers were detected only in the peripheral zone, in 4 (8.0%) only in the transition zone, and in 22 (44.0%) in both zones. No distinguishing characteristics could be determined for the cancers detected in the transition zone only. CONCLUSIONS: Although the cancer detection rate for the transition zone was significantly lower than for the peripheral zone, it was higher than that reported in most other studies which may have included biopsy specimens from patients with advanced prostate cancers. The usefulness of transition zone biopsies for the detection of early-stage prostate cancer, especially in patients with a PSA gray zone, can, therefore, not be denied.     

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.     

Repeat biopsy of the suspicious prostate cancer: especially the usefulness of MRI

Among patients with negative initial biopsies of the prostate, 51 patients underwent total 59 repeat biopsies at the Department of Urology of Ikeda Municipal Hospital between January 1998 and April 2004. Overall 26 patients (44.1%) were confirmed to have cancer, 22 patients by second repeat biopsy (22/51), four patients by third biopsy (4/7) and none by fourth biopsy (0/1). Clinical parameters (age, PSA, PSA density, PSA velocity) were analyzed for the possibility to predict the pathological outcome. Significant differences between the positive biopsy group and the negative biopsy group were obtained in age, PSA level and prostatic volume. Of the diagnostic evaluations including palpation and imaging studies (DRE, TRUS, MRI), the most powerful predictor for prostate cancer seemed to be the MRI findings, especially in the cases of short-interval repeat biopsy. Biopsies directed at the positive lesion on MRI in addition to systematic prostate biopsies should be useful.     

Detection of residual prostate cancer after radiotherapy by sonographically guided needle biopsy.

Detection of persistent or recurrent prostate cancer by digital rectal examination (DRE) after definitive radiotherapy is difficult. With the availability of transrectal ultrasonography (TRUS), the detection of prostate cancer has improved substantially. Since 1987 we have used TRUS to evaluate the prostate after definitive radiotherapy. A hypoechoic lesion suggestive of cancer was identified in 45 of 56 patients (80%) studied. Sonographically directed transrectal needle biopsies were performed in 27 of these (60%), and 16 (59%) were positive for cancer. The presence of a palpable nodule suggestive of cancer (present in 7 patients) was not predictive of a positive biopsy specimen. In 14 patients ultrasound-guided and digitally-guided biopsies were performed at the same time; 8 (57%) of the ultrasound-guided biopsy specimens were positive compared with only 4 (29%) of the digitally-guided biopsy specimens. In all 7 patients with an elevated serum level of prostate-specific antigen (PSA) an ultrasound-guided biopsy result was positive. Random biopsies of sonographically normal (isoechoic) areas of the prostate were performed in 8 patients, but only 2 specimens (25%) were positive for cancer. Ultrasound-guided transrectal biopsy of hypoechoic lesions was a safe and effective technique for identifying residual cancer in the irradiated prostate, regardless of the palpable findings. In the presence of an elevated PSA level, such biopsies invariably identified residual cancer. The use of TRUS, ultrasound-guided biopsy, and the measurement of PSA, in addition to DRE, may aid in the detection of residual cancer after definitive radiotherapy.     

Saturation technique does not improve cancer detection as an initial prostate biopsy strategy

PURPOSE: We reported on the results of a sequential cohort study comparing office based saturation prostate biopsy to traditional 10-core sampling as an initial biopsy. MATERIALS AND METHODS: Based on improved cancer detection of office based saturation prostate biopsy repeat biopsy, we adopted the technique as an initial biopsy strategy to improve cancer detection. Two surgeons performed 24-core saturation prostate biopsies in 139 patients undergoing initial biopsy under periprostatic local anesthesia. Indication for biopsy was an increased PSA of 2.5 ng/dl or greater in all patients. Results were compared to those of 87 patients who had previously undergone 10-core initial biopsies. RESULTS: Cancer was detected in 62 of 139 patients (44.6%) who underwent saturation biopsy and in 45 of 87 patients (51.7%) who underwent 10-core biopsy (p >0.9). Breakdown by PSA level failed to show benefit to the saturation technique for any degree PSA increase. Men with PSA 2.5 to 9.9 ng/dl were found to have cancer in 53 of 122 (43.4%) saturation biopsies and 26 of 58 (44.8%) 10-core biopsies. Complications included 3 cases of prostatitis in each group. Rectal bleeding was troublesome enough to require evaluation only in 3 men in the saturation group and 1 in the 10-core group. CONCLUSIONS: Although saturation prostate biopsy improves cancer detection in men with suspicion of cancer following a negative biopsy, it does not appear to offer benefit as an initial biopsy technique. These findings suggest that further efforts at extended biopsy strategies beyond 10 to 12 cores are not appropriate as an initial biopsy strategy.     

血清PSA密度变化对前列腺癌高危人群的诊断价值

目的:探讨前列腺特异抗原(PSA)、前列腺特异抗原密度(PSAD)变化对前列腺癌高危人群的诊断价值。方法:对初次活检阴性的432例患者进行随访,其中79例重复穿刺活检,确诊前列腺癌27例(34.2%),消化道来源肿瘤1例,BPH25例,前列腺上皮内肿瘤(PIN)13例,慢性前列腺炎13例。对重复活检患者的PSA、PSAD等临床资料进行统计分析。结果:配对t检验显示,良性病变首末次穿刺前PSA、PSAD差异均无统计学意义,而前列腺癌末次穿刺前PSA、PSAD较首次穿刺前升高,差异有统计学意义。以PSA>4ng/ml筛选前列腺癌,其敏感性、特异性、阳性预测值分别为92.5%、17.6%、37.6%,PSA末-PSA首>0筛选前列腺癌的敏感性、特异性、阳性预测值分别为85.2%、41.2%、40.4%;而以PSAD末-PSAD首>0筛选前列腺癌的敏感性、特异性、阳性预测值分别为81.5%、54.9%、48.9%。结论:在前列腺癌高危人群中应该重复穿刺,以减少漏诊;以PSAD动态升高来指导穿刺,可以明显提高阳性率。     

Prostate specific antigen adjusted for transition zone epithelial volume: the powerful predictor for the detection of prostate cancer on repeat biopsy

PURPOSE: The indications for repeat prostate biopsy for persistently increased prostate specific antigen (PSA) in men with prostate cancer never detected on previous biopsy are not clear. In this study we determined that PSA adjusted for transition zone (TZ) epithelial volume is the most powerful predictor for detecting prostate cancer on repeat biopsy. MATERIALS AND METHODS: Repeat prostate biopsies including additional TZ cores were performed in 75 men with PSA between 4.0 and 10.0 ng/ml. TZ epithelial volume was calculated by multiplying TZ volume by the percent of epithelium, which was measured by morphometric analysis using image analysis computer software. RESULTS: Prostate cancer was detected on repeat biopsy in 19 of the 75 patients. Patients with prostate cancer had a significant smaller percent area of epithelium or glandular lumen than those without cancer. In patients without prostate cancer TZ epithelial volume significantly correlated with total PSA. According to ROC analysis PSA adjusted for TZ epithelial volume had the greatest AUC for cancer detection (0.879). This parameter was able to avoid more than 90% of unnecessary repeat biopsies with 90% sensitivity. Multiple logistic regression analysis showed that PSA complex adjusted for TZ epithelial volume was the significant independent predictor of cancer. CONCLUSIONS: PSA adjusted for TZ epithelial volume is the most powerful predictor of cancer in men who have undergone previous negative prostate biopsies and in whom PSA remains between 4.0 and 10.0 ng/ml.     

Examination of the 3 molecular forms of serum prostate specific antigen for distinguishing negative from positive biopsy: relationship to transition zone volume

PURPOSE: We evaluated the relative usefulness of total, free and complexed serum prostate specific antigen (PSA), and their ratios for distinguishing positive from negative biopsy of prostates in a university referral practice. MATERIALS AND METHODS: We compared 90 consecutive men who had 2 sets of 6 negative systematic biopsies with 70 who had at least 5 mm. of prostate cancer in systematic biopsies during the same period at our institution. Total prostate and transition zone volumes were determined by transrectal ultrasound. The Bayer, DPC and Hybritech assays were performed to measure total, free and complexed serum PSA. Receiver operating characteristics curves were constructed for all forms of serum PSA and their ratios as well as prostate size to distinguish true positive (sensitivity) from false-positive (1 minus specificity) fractions. RESULTS: Complexed PSA was only marginally better than total serum PSA. Free-to-total, complexed-to-total and prostate size had highly significant areas under the curves of greater than 80%. Free PSA only was better than complexed or total PSA. When factored by prostate volume, total PSA performed as well as the PSA ratios, and transition zone volume was consistently better than total prostate volume. DPC free-to-total ratios were equivalent to Hybritech ratios in all respects. CONCLUSIONS: Complexed PSA is only marginally better than total PSA for distinguishing negative from positive biopsy of prostates. It is inferior to free PSA and far less useful than free-to-total or complexed-to-total ratios. Prostate size is a decisive variable in men in whom we avoided the expected 25% false-negative biopsy rate in terms of specificity and hopefully avoided insignificant cancer in terms of sensitivity. In the future the performance of PSA serum markers should be related to a transition zone volume of less than 20, 20 to 60 and greater than 60 gm. when comparing assays to each other.     

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.     

Use of extended pattern technique for initial prostate biopsy

PURPOSE: An extended prostate biopsy schema has been advocated at initial prostate biopsy to decrease the rate of false-negative cancer cases. However, critics have raised concerns that this may lead to the greater detection of clinically insignificant cancers. We examined the impact of using an extended pattern schema on cancer detection and also on the finding of smaller and clinically insignificant cancer. MATERIALS AND METHODS: Clinical data, including patient age, race, prebiopsy prostate specific antigen (PSA), digital rectal examination, prostate volume, number of needle cores and biopsy findings were abstracted from the medical records of all patients who underwent prostate biopsy in a 5-year period. Extended pattern prostate biopsy was defined as more than 10 cores. Clinically insignificant cancer was defined as a maximal tumor dimension of 1.0 cm or less, Gleason sum 6 or less and organ confined disease at radical prostatectomy. Adjusted regression models were developed to assess the independent effects of using an extended biopsy pattern on the detection of cancer overall and on the detection of clinically insignificant cancer. RESULTS: A total of 740 men with a mean age of 62.6 years were referred for prostate biopsy. Median PSA was 5.7 ng/ml and prostate volume was 39.7 cc. The OR for detecting prostate cancer was 1.55 (95% CI 1.09 to 2.19) for the extended pattern compared with standard biopsy. Of the subset of 136 patients who underwent radical prostatectomy 12.6% had clinically insignificant cancer. However, in contrast to overall cancer detection, extended pattern prostate biopsy was not found to be associated with an increased risk of detecting smaller or clinically insignificant cancer. PSA density was the single parameter found to be independently associated with the detection of clinically insignificant cancer (95% CI 0.20 to 0.98). CONCLUSIONS: Using an extended prostate biopsy pattern involving more than 10 cores increases the likelihood of detecting prostate cancer. A significant association between more needle cores at initial prostate biopsy and finding smaller and clinically insignificant cancer was not apparent.     

Detection of prostate cancer with 11C-methionine positron emission tomography

PURPOSE: We studied the detection of primary prostate cancer with positron emission tomography (PET) using C-labeled methionine (MET) in patients with increased prostate specific antigen (PSA) levels and repeatedly negative biopsies. MATERIALS AND METHODS: A total of 20 consecutive patients with increased serum PSA and negative repeat biopsies were included in the study. Patient age ranged from 52 to 75 years (average 65). PSA levels ranged from 3.49 to 28.6 ng/ml (average 9.36). Dynamic PET images were obtained from the prostate region using C-labeled MET. Suspicious accumulations of the tracer were anatomically localized using magnetic resonance images and were used as guidance during the next biopsy. RESULTS: PET was positive in 15 (75%) patients, in 7 of whom (46.7%) the next repeat biopsy verified carcinoma. The overall detection rate was 35% (7 of 20) and 46.7% (7 of 15) in the whole group and in the positive PET group, respectively. All 5 of 5 patients with negative MET PET had negative biopsies. CONCLUSIONS: MET PET of the prostate with short dynamic scanning and multicore biopsy is a useful method to ensure a high detection rate of prostate cancer in patients with increased PSA and repeat negative biopsies.     

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.