Extended prostate needle biopsy improves concordance of Gleason grading between prostate needle biopsy and radical prostatectomy

Effect of the number of biopsy cores on prostate cancer detection and staging

Digital rectal examination, serum concentration of prostate cancer-specific antigen and transrectal ultrasound-guided biopsies are currently the main diagnostic tools to detect evidence of prostate cancer. Different prostatic biopsy strategies have been proposed in order to achieve an optimal prostate cancer detection rate and an accurate characterization of prostate cancer stage and grade. We examined the role of the number of biopsy cores on prostate cancer detection rates at initial and repeat biopsies. Moreover, we examined the relationship between the number of biopsy cores and the detection of insignificant prostate cancer. Finally, we reviewed the ability of biopsy cores in predicting prostate cancer stage and grade at radical prostatectomy. We relied on a PubMed systematic review of the contemporary English language literature using the terms ‘prostate cancer’, ‘diagnosis’, ‘transrectal ultrasound’ and ‘prostate biopsy’.

Clinical implications of changing definitions within the Gleason grading system

Remarkably, more than 40 years after the inception of the Gleason grading system, it remains one of the most powerful prognostic predictors in prostate cancer. Gleason's original grading system, however, has undergone significant revision over the years, first by Gleason and his colleagues, and most recently at the 2005 International Society of Urological Pathology Consensus Conference. The consensus conference and subsequent articles proposing further modifications have helped pathologists to adapt the Gleason grading system to current urologic practice in a uniform manner. The changing definitions of Gleason pattern 3 and 4 prostatic adenocarcinoma have tended to narrow the scope of pattern 3 carcinoma and widen the scope of pattern 4 carcinoma. These modifications have had an important role in improving the inter-observer reproducibility of the Gleason system. Whether these changes have a significant impact on the clinical treatment of prostate cancer remains to be seen. However, as many of these modifications are supported only by a few studies, long-term follow-up studies with clinical end points are essential to validate these recommendations.

Will the modification of the Gleason grading system affect the urology practice?

The aim of the present study was to determine how the modified Gleason grading (mGG) system affects the score discrepancy between needle biopsy (NB) and radical prostatectomy (RP) and to investigate the effect of the modified scores on nomogram predictions. When the conventional Gleason grading (cGG) and mGG systems were compared, a new Gleason score was obtained in the NBs for 40 out of 97 patients (41.2%; P < .001) and in the RP specimens for 15 out of 97 patients (15.5%; P = .005). The agreement between the NBs and RP specimens rose from 31.9% to 44.3% with the mGG system (P = .017). However, when the predictions calculated with the location of modified Gleason scores in the Memorial Sloan Kettering Cancer Center nomogram were compared with those of the conventional Gleason scores, higher pathological stage and lower life expectancy predictions were obtained. Therefore, when a clinician is making a choice from therapeutic options, this change should be taken into account.

Mechanically assisted 3D ultrasound guided prostate biopsy system

There are currently limitations associated with the prostate biopsy procedure, which is the most commonly used method for a definitive diagnosis of prostate cancer. With the use of two-dimensional (2D) transrectal ultrasound (TRUS) for needle-guidance in this procedure, the physician has restricted anatomical reference points for guiding the needle to target sites. Further, any motion of the physician's hand during the procedure may cause the prostate to move or deform to a prohibitive extent. These variations make it difficult to establish a consistent reference frame for guiding a needle. We have developed a 3D navigation system for prostate biopsy, which addresses these shortcomings. This system is composed of a 3D US imaging subsystem and a passive mechanical arm to minimize prostate motion. To validate our prototype, a series of experiments were performed on prostate phantoms. The 3D scan of the string phantom produced minimal geometric distortions, and the geometric error of the 3D imaging subsystem was 0.37 mm. The accuracy of 3D prostate segmentation was determined by comparing the known volume in a certified phantom to a reconstructed volume generated by our system and was shown to estimate the volume with less then 5% error. Biopsy needle guidance accuracy tests in agar prostate phantoms showed that the mean error was 2.1 mm and the 3D location of the biopsy core was recorded with a mean error of 1.8 mm. In this paper, we describe the mechanical design and validation of the prototype system using an in vitro prostate phantom. Preliminary results from an ongoing clinical trial show that prostate motion is small with an in-plane displacement of less than 1 mm during the biopsy procedure.

Biopsies performed at tertiary care centers are superior to referral biopsies in predicting pathologic Gleason sum

OBJECTIVE

Biopsy grading at tertiary care centers may or may not be superior to biopsies performed at referral institutions.

METHODS

Referral biopsy and tertiary care center biopsy Gleason sums were studied in 758 men treated with radical prostatectomy (RP) at a tertiary care center between 1992 and 2004. Grade agreement was calculated using the Cohen kappa (ê). Logistic regression models predicting high-grade prostate cancer at RP were fitted using either referral or tertiary care center biopsies. Comparison of bootstrap-corrected predictive accuracy estimates were performed using the Mantel-Haenszel test.

RESULTS

Grade agreement between biopsy and RP Gleason sum was higher (P = 0.003) for tertiary care center biopsies v referral biopsies (55.5% v 47.9%; P = 0.003). Upgrading occurred in 39.8% of referral biopsies v 32.6% of tertiary care center biopsies (P = 0.03). Tertiary care center biopsies were more accurate in determining RP Gleason sum than referral biopsies (71.5% v 65.6%, P = 0.04).

CONCLUSION

More accurate prediction of RP Gleason grade may be achieved if biopsy is performed and graded at tertiary care centers.

Laparoscopic pelvic lymph-node dissection in prostate cancer before external beam radiotherapy: Risk factors of nodal involvement and relapse following intended curative treatment

OBJECTIVE

To report experience with laparoscopic pelvic lymph-node dissection (LPLND) in patients with prostate cancer before radiotherapy. Selection of risk factors for nodal involvement (N1) and recurrence following radiotherapy was made.

MATERIAL AND METHODS

From November 1999 to June 2007, 177 patients with prostate cancer underwent LPLND at this department. The lymphadenectomy was limited to the obturator fossa bilaterally. Patients without nodal involvement were offered external beam radiotherapy with adjuvant hormone treatment.

RESULTS

Complications occurred in 17 patients (9%). The majority of these were minor and were managed by conservative methods. Twenty-six patients (15%) were diagnosed with N1. High Gleason score and a high percentage of positive needle core biopsies were both risk factors of N1 as well as recurrent disease following radiotherapy (p<0.01 and 0.01, respectively). Clinically, T3 disease was associated with a risk of recurrence but not N1. High prostate-specific antigen (PSA) nadir was also a significant predictor of recurrence. Neither pretreatment PSA nor prostate volume was associated with N1 or recurrence.

CONCLUSIONS

LPLND is a safe, well-established staging modality in clinically localized prostate cancer before radiotherapy. Risk factors upon diagnosis may be useful in the estimation of N1 and risk of recurrence.

The effect of the number of biopsy cores on the concordance between prostate biopsy and prostatectomy Gleason score: a prostate volume-controlled study

CONTEXT

Studies analyzing the concordance of biopsy and radical prostatectomy (RP) Gleason scores have limitations. Some included 2 or more centers, used historical controls from the early prostate specific antigen era or lacked a clear definition of the biopsy schemes. Furthermore, most did not control the results for prostate volume.

OBJECTIVE

To confirm whether prediction of RP Gleason score can be optimized by taking more biopsy cores in a contemporary series of patients, with pathologic samples analyzed by the same pathologist, and controlling these results for prostate volume.

DESIGN

The study comprised a retrospective case-control analysis of 393 patients with prostate cancer treated with RP. Patients were divided into 3 groups: those in group 1 underwent a 6-core biopsy; group 2, an 8-core biopsy; and group 3, a 10 or more-core biopsy. Concordance rates between biopsy and RP Gleason scores, as well as the rates of undergrading and overgrading, were determined for each biopsy scheme.

RESULTS

Concordance rates were 60.9%, 58.3%, and 64.6% for patients from groups 1, 2, and 3, respectively (P = .18). When we analyzed patients with prostate volumes of less than 50 cm(3), concordance rates were 58.3%, 58.3%, and 65.1% for each group, respectively (P = .03). Among patients with prostate volumes of 50 cm(3) or more, concordance rates were 70%, 58.1%, and 63.6%, respectively (P = .66).

CONCLUSIONS

Taking 10 or more cores can improve the prediction of RP Gleason score in patients with prostate volumes of less than 50 cm(3). For patients with prostate volumes of 50 cm(3) or more, increasing the biopsy cores to 10 or more did not improve prediction of RP Gleason score.

Comparing the Gleason prostate biopsy and Gleason prostatectomy grading system: the Lahey Clinic Medical Center experience and an international meta-analysis

BACKGROUND

The accuracy of the prostate biopsy Gleason grade to predict the prostatectomy Gleason grade varies tremendously in the literature.

OBJECTIVES

Determine the accuracy and distribution of the prostate biopsy Gleason grade and prostatectomy Gleason grade at LCMC (Lahey Clinic Medical Center) and worldwide.

DESIGN, SETTING, AND PARTICIPANTS

Participants included 2890 patients who had not received preoperative hormones, and for whom preoperative and postoperative Gleason sums were available. Participants underwent radical prostatectomy at LCMC, an academic referral center, from 1982-2007. Studies for the meta-analysis were selected from Medline: 1994-2007. Search criteria included keywords "Gleason," "biopsy," and "prostatectomy," >/=200 patients, and whether the biopsy and prostatectomy Gleason scores categorized into the predefined Gleason grades. The meta-analysis included 15 studies and the LCMC database for 14,839 total patients.

MEASUREMENTS

Gleason scores 2-6, 7, and 8-10 were converted to low, moderate, and high grade, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value were calculated. The kappa statistic and chi-square were used to compare biopsy and prostatectomy grades.

RESULTS AND LIMITATIONS

The percentage of patients in whom the prostatectomy grade was accurately predicted, upgraded, and downgraded was 58%, 36%, and 5% at LCMC and 63%, 30%, and 7% in the meta-analysis, respectively. The PPV for low-, moderate-, and high-grade cancer was 54%, 70%, and 60% for LCMC and 62%, 70%, and 50% for the meta-analysis, respectively. The sensitivity decreased with increasing Gleason grade (low, moderate, and high) for LCMC (91%, 38%, 28%) and the meta-analysis (90%, 40%, 33%), respectively. The distribution of low-, moderate-, and high-grade cancer on biopsy (69%, 25%, and 6%) and prostatectomy specimen (47%, 44%, and 9%) demonstrated only "fair" agreement (kappa, 0.37).

CONCLUSIONS

Patients and practitioners need to be cognizant of significant upgrading for low-grade disease and the downgrading for high-grade disease.

Trends in Gleason score: concordance between biopsy and prostatectomy over 15 years

OBJECTIVES

To assess the changes in the concordance rate of prostate biopsy and radical prostatectomy (RP) Gleason score (GS) over 15 years.

METHODS

We reviewed 1670 consecutive patients who underwent RP between 1992 and 2006. We excluded patients who underwent neoadjuvant hormone therapy or salvage RP, or who had incomplete data. Patients who had RP during 1992 through 1996, 1997 through 2001, and 2002 through 2006 were assigned to groups 1, 2, and 3, respectively. All clinical and pathological data were collected retrospectively. We defined overgrading as a biopsy GS higher than the RP Gleason score. Undergrading was a biopsy GS less than the RP Gleason score. The GS concordance between biopsy and RP was evaluated by kappa coefficient.

RESULTS

A total of 1363 patients satisfied the inclusion criteria. Biopsy and RP Gleason score categories correlated exactly in 937 (69%) men. Gleason undergrading occurred in 361 (26%) men and overgrading in 65 (5%). The exact correlation of GS between biopsy and RP was 58%, 66%, and 75% in groups 1, 2, and 3, respectively. The most common discordant finding was undergrading of the biopsy specimen. The number of cases with exact correlation was highest in GS 7 (78%). Undergrading was more in GS 6 or less (35%) and overgrading was more in the GS 8 through 10 (35%) category.

CONCLUSIONS

This large, single institutional study confirms increasing concordance of Gleason scores in prostate needle biopsies and surgical specimens. This is reassuring for patients assessing various treatment options for prostate cancer.

Prostate cancer volume at biopsy predicts clinically significant upgrading

PURPOSE

A significant proportion of patients with prostate cancer with Gleason score 6 disease at biopsy is upgraded to Gleason score 7 or higher after radical prostatectomy, increasing the risk of adverse outcome. We identified clinical and pathological parameters that predict pathological upgrading in this population.

MATERIALS AND METHODS

A total of 268 patients with biopsy Gleason score 6 prostate cancer who underwent biopsy and radical prostatectomy between October 1999 and January 2007 were included in the study. Pretreatment characteristics were used to identify predictors of pathological upgrading. Upgrading significance was established by comparing radical prostatectomy pathology between cases that were and were not upgraded.

RESULTS

A total of 134 patients (50%) were upgraded postoperatively to Gleason score 7 or higher. Preoperative prostate specific antigen greater than 5.0 ng/ml (p = 0.036), prostate weight 60 gm or less (p = 0.004) and more cancer volume at biopsy, defined by cancer involving greater than 5% of the biopsy tissue (p = 0.002), greater than 1 biopsy core (p <0.001) or greater than 10% of any core (p = 0.014), were associated with pathological upgrading. Upgraded patients were more likely to have extraprostatic extension and positive surgical margins at radical prostatectomy (p <0.001 and 0.001, respectively).

CONCLUSIONS

Prostate specific antigen, prostate volume and biopsy cancer volume predict clinically significant upgrading in patients diagnosed with Gleason score 6 disease. These parameters may be valuable in the pretreatment risk assessment of this patient population.

Does prostate biopsy Gleason score accurately express the biologic features of prostate cancer?

PURPOSE

To correlate Gleason grading in prostate biopsies with the final Gleason score in radical prostatectomy specimens, and to investigate predictors for concordance and preoperative undergrading.

MATERIALS AND METHODS

The charts of 303 patients who underwent radical retropubic prostatectomy between 1992 and 2002 were retrospectively reviewed. Prostate biopsy and surgical specimen Gleason scores and correlative clinical data were recorded, and a multivariate analysis model was applied.

RESULTS

Data were available in 293 cases (97%). The preoperative biopsy predicted the prostatectomy Gleason score accurately in 51% and undergraded them in 41% of the patients. Accuracy rates were significantly higher for Gleason scores 7-10 compared to low Gleason scores (2-4), concordance 90% and 6%, respectively (P < 0.01). Moreover, accuracy rates were higher in patients with prostate-specific antigen (PSA) higher than 10 ng/ml (85% vs. 40%; P < 0.01) and prostate glands smaller than 55 g (68% vs. 38%; P < 0.01). In 233 patients, the biopsy Gleason score did not include 4 or 5 components. Upgrading to 4 or 5 in 1 of the components was noted in 32 patients (14%). Multivariate analysis revealed that upgrading is associated with preoperative serum PSA (odds ratio 1.05; P < 0.05) and the percentage of positive cores in the biopsy (odds ratio 1.47; P < 0.001).

CONCLUSIONS

Biopsy Gleason scores of 2-4, low PSA, and a low percentage of positive cores in the biopsy can predict the biopsy driven biologically significant undergrading of 1 of the components of the Gleason score that may adversely affect therapeutic decisions.

Improved Accuracy in Predicting the Presence of Gleason Pattern 4/5 Prostate Cancer by Three-Dimensional 26-Core Systematic Biopsy

OBJECTIVES

To evaluate whether three-dimensional 26-core (3D26) prostate biopsy improves the accuracy in predicting the presence of Gleason pattern 4/5 cancer compared with extended transrectal 12-core (TR12) or transperineal 14-core (TP14) biopsy schemes.

METHODS

We studied 143 consecutive men in whom prostate cancer was diagnosed by the 3D26 biopsy and who underwent radical prostatectomy (RP) without neoadjuvant treatment. All histologic grading was reevaluated by a single pathologist according to the 2005 International Society of Urological Pathology Consensus Conference on Gleason Grading. Cancer grade was categorized into high grade (Gleason pattern 4/5 cancer present) and non-high grade (absent) in both biopsy and RP specimens. Since TR12 and TP14 biopsy schemes represent subsets of the 3D26 biopsy, we could compare these schemes directly in an identical patient cohort.

RESULTS

There was a grade agreement between 3D26 biopsy and RP in 132 (92.3%) cancers. Grade concordance between biopsy and RP was significantly better in 3D26 biopsy than in TR12 (83.5%, p=0.025) biopsy. Risk of underestimation of cancer grade by 3D26 biopsy (26.5%) was significantly lower than that by TP14 (51.4%, p=0.034). Grade concordance between 3D26 biopsy and RP was not according to clinical variables including prostate volume, clinical stage, prostate-specific antigen (PSA), and PSA density.

CONCLUSIONS

We demonstrated that the 3D26 biopsy can accurately predict the presence of Gleason pattern 4/5 cancer on RP specimens with a high concordance rate of 92.3%, a value significantly higher than that between extended TR12 biopsy and RP specimens.

Increasing the number of biopsies increases the concordance of Gleason scores of needle biopsies and prostatectomy specimens

PURPOSE

To determine the importance of increasing the number of biopsy cores to decrease the discrepancy of Gleason scores of needle biopsy and radical prostatectomy specimens.

MATERIALS AND METHODS

Between May 1998 and July 2005, 392 patients with clinically localized prostate cancer diagnosed by 18-gauge transrectal needle biopsy underwent radical prostatectomy. We categorized the cohort into 2 groups according to the number of the cores. Group 1 consisted of 206 patients diagnosed by extended biopsies (> or =10 cores, range 10-14, median 11). The remaining 186 patients who were diagnosed by sextant biopsies were categorized as being in group 2. Preoperative clinical variables, including patient age, digital rectal examination findings, serum prostate-specific antigen, and the number of cores positive for cancer the parameters, were assessed in both groups. The concordance of Gleason scores in both groups were analyzed by both individual Gleason scores and clinical subgroups of Gleason scores: 2-4 (well differentiated), 5-6 (moderately differentiated), 7 (intermediate), and 8-10 (poorly differentiated).

RESULTS

Needle biopsies revealed moderately differentiated tumors (Gleason 5-6) for the 2 groups (55.3% and 60.2%). Gleason scores of the needle biopsies were identical to that of the prostatectomy specimen in 116 (56.31%) and 76 cases (40.86%) for each group (kappa: 0.432 and 0.216 for each group, respectively). Gleason score of the needle biopsy differed by 1 grade in 56 (27.18%) and 84 cases (45.16%), and by > or =2 units in 34 (16.50%) and 26 cases (15.05%) for each group, respectively. Of the specimens, 34% were undergraded, and 10% were overgraded in group 1. These rates were 38% and 22% in group 2, respectively. A total of 70% in group 1 and 56% in group 2 remained in the same categorical group, 28% and 32% of the specimens were undergraded, and 4% and 12% were overgraded in groups 1 and 2, respectively. In group 1, the number of patients with Gleason scores of 2-4, 5-6, 7, and 8 were 9.7%, 55.3%, 21.4%, 13.6%, and 1.9%, 47.6%, 32%, 18.4%, graded by needle biopsies and radical prostatectomy specimens, respectively. However, in the sextant group, the change was the number of patients with Gleason scores of 2-4, 5-6, 7, and 8-10 was 5.4% 60.2%, 24.7%, and 9.7%, detected by needle biopsies, respectively. Radical prostatectomy specimens revealed the same Gleason categories in 4.3%, 41.9%, 38.7%, and 15.1%, respectively. There was no correlation between categorized prostate-specific antigen levels and concordance of the Gleason grade. Age and digital rectal examination results did not affect Gleason correlation.

CONCLUSIONS

We have shown that an extended biopsy scheme beyond its superior diagnostic capability also improves the concordance of Gleason scores of needle biopsies and radical prostatectomy specimens.

Extended and saturation prostatic biopsy in the diagnosis and characterisation of prostate cancer: a critical analysis of the literature

OBJECTIVE

To review and critically analyse all the recent literature on the detection and characterisation of prostate cancer by means of extended and saturation protocols.

METHODS

A systematic review of the literature was performed by searching MedLine from January 1995 to April 2007. Electronic searches were limited to the English language, and the key words "prostate cancer," "diagnosis," "transrectal ultrasound (TRUS)," "prostate biopsy," and "prognosis" were used.

RESULTS

The prostate biopsy technique has changed significantly since the original Hodge sextant biopsy protocol. Several types of local anaesthesia are now available, but periprostatic nerve block (PPNB) has proved to be the most effective method to reduce pain during TRUS biopsy. It remains controversial whether PPNB should be associated with other medications. The optimal extended protocol (sextant template with at least four additional cores) should include six standard sextant biopsies, with additional biopsies (up to 12 cores) taken more laterally (anterior horn) to the base and medially to the apex. Repeat biopsies should be based on saturation biopsies (number of cores >/= 20) and should include the transition zone, especially in a patient with an initial negative biopsy. As a means of increasing accuracy of prostatic biopsy and reducing unnecessary prostate biopsy, colour and power Doppler imaging, with or without contrast enhancement, and elastography now can be successfully adopted, but their routine use is still controversial.

CONCLUSION

Extended and saturation biopsy schemes should be performed at first and repeat biopsy, respectively. The widespread use of local anaesthesia makes the procedures more comfortable.

Cost-Benefit and Outcome Analysis: Effect of Prostate Biopsy Undergrading

OBJECTIVES

Brachytherapy is a widely used treatment for localized prostate cancer (CaP) and is only appropriate as monotherapy for low-risk cancer. The predicted response to therapy is defined by the pretreatment parameters, of which the biopsy Gleason grade is central. However, the biopsy grade often misrepresents the true pathologic grade. We examined the impact of incorrect biopsy grading on brachytherapy outcomes.

METHODS

We constructed a decision analytic model to assess the theoretical performance of brachytherapy for a theoretical cohort of men with Gleason score 6 CaP who underwent radical prostatectomy. The variables regarding biopsy Gleason scores and the correlation with the surgical specimen findings were generated from the institutional data. The ranges for these variables, biochemical performance of brachytherapy, costs, and disease state utilities, were obtained from a data review.

RESULTS

For the base case, 67% of biopsy grades correlated with the pathologic grade. With this concordance, 8% of failures could be attributed, in part, to undergrading. On the basis of the model assumptions, as concordance worsened to 50%, the rate of undergraded failures increased to 12%. After adjusting for the quality of life associated with higher-grade disease and the risk of biochemical failure, the aggregate cost of treatment of biopsy grade 6 disease was increased by 8% because of undergrading ($75,700 versus $81,500 per case). The bulk of this effect was the cost of failure among patients with undergraded disease.

CONCLUSIONS

Brachytherapy for Gleason score 6 disease is reported to have excellent results. Undergrading of prostate biopsies can negatively affect clinical outcomes and increase treatment costs. Although the risk is low, it should be considered when counseling patients with CaP.

Validation of a prediction model for low volume/low grade cancer: application in selecting patients for active surveillance

PURPOSE

We previously demonstrated that assessment of the number of positive cores, tumor length in a core, Gleason score and prostate volume significantly enhanced the accuracy of a prediction model for low volume/low grade cancer in men who had undergone extended biopsy. To determine the validity of the model, we applied it to an independent population of men with prostate cancer.

MATERIALS AND METHODS

The study group included 170 men who had undergone radical prostatectomy without neoadjuvant therapy. In all cases, prostate cancer was diagnosed on only 1 positive core of a 10-core extended biopsy. We assessed the accuracy of the model, which consists of tumor length less than 2 mm, Gleason score 3+4 or less and prostate gland volume greater than 50 cc in predicting the occurrence of low volume/low grade cancer (defined as tumor volume less than 0.5 cc, no Gleason grade 4 or 5 disease, and organ confined disease).

RESULTS

Of the patients 101 (59.4%) had low volume/low grade cancer. Our model using all 3 previously mentioned variables had the highest performance, demonstrating a positive predictive value of 70.4% (88 of 125), a negative predictive value of 71.1% (32 of 45) and a diagnostic accuracy of 70.6% (120 of 170). This model performed better than a model based on tumor length only (positive predictive value, negative predictive value and diagnostic accuracy 68.1%, 57.9% and 64.7%, respectively) or a model based on tumor length and Gleason score (positive predictive value, negative predictive value and diagnostic accuracy 70.0%, 60.0% and 66.5%, respectively).

CONCLUSIONS

This study validates that our model with a combination of tumor length, Gleason score and prostate volume is predictive for low volume/low grade cancer in an independent population of men who demonstrated only 1 positive core in an extended biopsy. This model can be used as a tool for selecting men for active surveillance.

Sentinel lymph node dissection for prostate cancer: experience with more than 1,000 patients

PURPOSE

We determined the incidence of positive pelvic lymph nodes in men undergoing radical retropubic prostatectomy and describe the correlation with prostate specific antigen, histological grade and stage. We examined whether tumor cells are localized in the sentinel nodes only or also in other nonsentinel lymph nodes.

MATERIALS AND METHODS

A total of 1,055 men with prostate cancer underwent radio guided pelvic lymph node dissection and radical retropubic prostatectomy. In men with prostate specific antigen 20 ng/ml or less and biopsy Gleason score 7 or less only sentinel nodes were removed. In men with prostate specific antigen more than 20 ng/ml or Gleason score greater than 7 extended pelvic lymph node dissection was also performed.

RESULTS

Positive lymph nodes were found in 207 men (19.6%). In 63.3% of the men these lymph nodes were detected outside of the region of standard lymphadenectomy. The percent of patients with positive nodes was greater than predicted by currently used nomograms. The higher the preoperative prostate specific antigen, pathological stage and grade, the greater the percent of men with positive sentinel and nonsentinel lymph nodes (p<0.001).

CONCLUSIONS

When deciding on pelvic lymph node dissection, sentinel or extended lymphadenectomy should be performed since more than half of patients have positive nodes outside of the region of standard lymphadenectomy. In cases of positive sentinel nodes extended lymph node dissection should be performed since tumor cells are also detectable in nonsentinel lymph nodes.

The incidence of high-grade prostatic intraepithelial neoplasia and atypical glands suspicious for carcinoma on first-time saturation needle biopsy, and the subsequent risk of cancer

OBJECTIVE

To investigate the detection rate and extent of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical glands (AG) suspicious for prostate cancer, and the cancer risk in subsequent biopsies, diagnosed by a first 24-core saturation biopsy, as although the optimum extent of biopsy is controversial there is a trend to increase the number of cores taken, and apart from detecting prostate cancer, identifying HGPIN and AG is associated with a greater risk of finding cancer in subsequent biopsies, thus warranting a closer follow-up.

PATIENTS AND METHODS

The study included 100 men with consecutive first-time saturation biopsies; the indications for biopsy were an abnormal digital rectal examination and/or a serum prostate-specific antigen (PSA) level of >2.5 ng/mL. Each biopsy specimen was reviewed retrospectively by two pathologists to confirm the histological diagnosis. The number and percentage of cores positive for HGPIN, bilateral involvement and multifocality (HGPIN involving two or more cores) were recorded in each case. The presence of AG and cancer was also recorded. An extended (10-12 cores) repeat biopsy was available in 23 patients.

RESULTS

The median (range) age and PSA level of the patients was 63 (41-80) years and 4.9 (1.5-67.0) ng/mL, respectively. Of the 100 patients, 34% had normal findings (benign prostatic tissue, BPT), 39% had cancer, 26% had HGPIN and cancer, 22% had HGPIN alone, and 5% had AG. Repeat biopsies were available in nine of the 22 (41%) patients with HGPIN, four of five with AG, and 10 of the 34 (29%) with BPT. The median (range) interval between the first and second biopsy was 13 (4-36) months. Prostate cancer was detected at the second biopsy in a third of patients with isolated HGPIN on the first biopsy, and one of the four with AG. None of the patients with BPT had cancer on re-biopsy. The cancer detection rate was significantly greater in patients with multifocal than in those with unifocal HGPIN (80% vs none, P = 0.010). The median number of cores and percentage of tissue involved by HGPIN was 3.5 (2-5) and 1.0 (0.5-1.2)%, respectively, in patients with cancer detected in repeat biopsies, compared to 1.0 (1-3) and 0.2 (0.2-0.6)% in patients without cancer on repeat biopsy (P = 0.023 and 0.015, respectively).

CONCLUSION

Identifying multifocal HGPIN on first saturation biopsy is associated with an overall cancer detection rate of 80% on repeat 10-12-core biopsy. Although there were few patients, the detection of multifocal HGPIN warrants additional searches for concurrent invasive carcinoma by repeated biopsy.

Poorly differentiated prostate cancer treated with radical prostatectomy: long-term outcome and incidence of pathological downgrading

PURPOSE

Patients with high grade (Gleason score 8 to 10) prostate cancer on biopsy are at high risk for cancer recurrence after local treatment, such as radiation therapy and radical prostatectomy. We examined long-term outcomes in patients with high grade prostate cancer on biopsy who were treated with radical prostatectomy alone. We also investigated the impact on outcomes of changes in the radical prostatectomy Gleason score.

MATERIALS AND METHODS

Of 5,662 patients who underwent radical prostatectomy during 20 years 238 had a biopsy Gleason score of 8 to 10. We analyzed the rate of biochemical recurrence in this subgroup according to the Gleason grade of cancer in the radical prostatectomy specimen.

RESULTS

Ten-year biochemical recurrence-free probability in the cohort was 39%. However, 45% of patients (95% CI 38 to 51%) with Gleason score 8 to 10 cancer on biopsy had a Gleason score of 7 or less in the radical prostatectomy specimen. These patients had a 10-year biochemical recurrence-free probability of 56% compared to 27% in those with a final Gleason score that remained 8 to 10 (p = 0.0004). On multivariate analysis neither prostate specific antigen nor biopsy features, including total number of cores, number of cores with cancer and percent of cancer in the cores, was a significant predictor of downgrading. However, clinical stage and biopsy Gleason score were significant with 58% of cT1c and 51% of biopsy Gleason score 8 cancers downgraded. Almost 65% of cT1c Gleason score 8 cancers were downgraded compared to 11% of cT3 Gleason score 9 cancers.

CONCLUSIONS

Patients diagnosed with poorly differentiated prostate cancer (Gleason score 8 to 10) on biopsy do not uniformly have a poor prognosis. Of the patients 39% remain free of cancer recurrence 10 years after radical prostatectomy. Of these cancers 45% have a lower Gleason score in the radical prostatectomy specimen and a correspondingly more favorable long-term outcome. Predictors of downgrading are lower clinical stage (cT1c) and Gleason score 8 in the biopsy specimen.

Prostate Cancers Scored as Gleason 6 on Prostate Biopsy are Frequently Gleason 7 Tumors at Radical Prostatectomy: Implication on Outcome

PURPOSE

Differentiation between Gleason score 6 and 7 in prostate biopsy is important for treatment decision making. Nevertheless, under grading errors compared with the actual pathological grade at radical prostatectomy are common. We compared the characteristics and outcomes of tumors that were scored 6 on prostate biopsy but were 7 on subsequent radical prostatectomy pathological evaluation to those in tumors with a consistent rating of Gleason score 6 or 7 at biopsy and surgery.

MATERIALS AND METHODS

We performed a retrospective database analysis from our referral center (1989 to 2004). We compared pre-prostatectomy characteristics, radical prostatectomy pathological features and the post-radical prostatectomy prostate specific antigen failure rate, defined as any 2 consecutive detectable prostate specific antigen measurements, in 3 subgroups of patients, including 156 with matched Gleason score 6 in the prostate biopsy and radical prostatectomy, 205 with upgraded Gleason score 6/7, that is prostate biopsy Gleason score 6 and radical prostatectomy Gleason score 7, and 412 with matched Gleason score 7 in the prostate biopsy and radical prostatectomy.

RESULTS

Radical prostatectomy Gleason score matched the prostate biopsy score in 38.2% of biopsy Gleason score 6 and 81.4% of biopsy Gleason score 7 cases. Higher prostate specific antigen was associated and an increased percent of cancer in the prostate biopsy was predictive of discordance between the prostate biopsy and radical prostatectomy Gleason scores (p <0.001). Margin (p = 0.0075) or seminal vesicle involvement (p = 0.0002), cancer volume (p <0.001) and the prostate specific antigen failures rate (p = 0.014) were significantly higher in under graded Gleason score 7 cancer compared to those in matched Gleason score 6 cases. However, they were comparable to those with a matched Gleason score 7 tumor grade (p = 0.66).

CONCLUSIONS

Almost half of tumors graded Gleason score 6 at biopsy are Gleason score 7 at surgery. Upgraded Gleason score 6 to 7 tumors have outcomes similar to those of genuine Gleason score 7 cancer. For prostate biopsy Gleason score 6 tumors clinicians should consider the overall likelihood of tumor upgrading as well as specific patient characteristics, such as prostate specific antigen and the percent of tumor in the prostate biopsy, when contemplating treatments that are optimized for low grade tumors, including watchful waiting or brachytherapy.

Should Men with Serum Prostate-Specific Antigen ≤4 ng/ml and Normal Digital Rectal Examination Undergo a Prostate Biopsy?

The clinical significance of a prostate cancer (PCa) cannot be determined solely by tumor volume (< or =0.5 cm(3)), as small tumors of higher Gleason grade and tumors occurring in younger men may become clinically significant even though the initial volume at diagnosis is small. A certain number of these minimal cancers are likely to remain clinically insignificant; however, it is unpredictable how many can progress beyond the curable stage by the time there is a rise in serum prostate-specific antigen (PSA) values. Compared to clinically detected PCa, PCa detected exclusively by PSA screening (clinical stage T1c) are less likely to be advanced but no more likely to be insignificant in terms of volume, pathologic stage, and Gleason pattern. Only 10-15% of PSA-detected cancers have the features of PCa found at autopsy or in cystoprostatectomy specimens. Actually, 25-30% of PCa are detected with PSA values between 2.5 and 4 ng/ml, and most of these cancers are clinically significant. Evidence from both retrospective and longitudinal studies has shown that the risk of a PCa is dependent on the patient's age and the initial serum PSA. This allows an individualized approach to PCa screening programs, and PSA cutoff values for biopsy indication may be lowered in selected patients.

Increased accuracy of biopsy Gleason score obtained by extended needle biopsy

PURPOSE

Accurate tumor grading is critical for adequate prostate cancer treatment. Nonetheless, the Gleason score of standard sextant biopsy correctly predicts the Gleason score of the radical prostatectomy specimen in about 50% of cases. We investigated if extended needle biopsy could improve biopsy Gleason score accuracy.

MATERIALS AND METHODS

Laparoscopic transperitoneal radical prostatectomy was performed in 135 patients. Prostate cancer was diagnosed in 89 cases by standard sextant transrectal (6 to 8 cores) biopsy and in 46 by extended needle (12 core transperineal under transrectal guidance) biopsy. Preoperative evaluation included digital rectal examination, prostatic specific antigen measurement, transrectal ultrasonography and endorectal coil magnetic resonance imaging in all patients. All biopsy and prostatectomy specimens were reviewed by a single pathologist.

RESULTS

Clinical characteristics were similar in the 2 groups. The concordance between prostate biopsy and radical prostatectomy Gleason score was 32 of 46 cases (70%) and 44 of 89 (49%) for 12 core and standard transrectal biopsy, respectively (z test p = 0.0127). Biopsy under grading was found in 11 of 46 cases (24%) and 35 of 89 (39%) (z test p = 0.0366), and biopsy over grading was found in 3 of 46 (6%) and 10 of 89 (11%) (z test p = 0.1894) with 12 core and standard transrectal biopsy, respectively. Primary Gleason pattern was predicted exactly by biopsy in 40 of 46 cases (87%) and 56 of 89 (63%) with 12 core and standard sextant biopsy, respectively (z test p = 0.0018).

CONCLUSIONS

Extended needle biopsy significantly increases the accuracy of biopsy Gleason score for assessing final prostate cancer grade.

Role of transperineal six-core prostate biopsy in patients with prostate-specific antigen level greater than 10 ng/mL and abnormal digital rectal examination findings

OBJECTIVES

To define whether six-core biopsies still have a role in patients presenting with prostate-specific antigen (PSA) levels greater than 10 ng/mL and abnormal digital rectal examination (DRE) findings. Recent studies have suggested that the six-core biopsy is inadequate for the diagnosis of prostate cancer; however, it remains controversial whether an increased number of cores is justified in all patients.

METHODS

From June 2002 to February 2005, 122 (18.8%) of 650 patients underwent prostate biopsy because of a PSA level greater than 10 ng/mL and abnormal DRE findings. All patients underwent transperineal ultrasound-guided prostate biopsy in a standardized fashion: a six-core biopsy was performed first, followed by six additional cores during the same session, four in the peripheral and two in the transition zone.

RESULTS

The detection rate in patients with a PSA level greater than 10 ng/mL and abnormal DRE findings was 72.1% (88 of 122) and 75.4% (92 of 122) using the 6-core and 12-core biopsy, respectively. One case of tumor was missed by the six-core biopsy among patients with a PSA level greater than 15 ng/mL and abnormal DRE findings. No cases of tumor were missed by six-core biopsy in the group with a PSA level greater than 20 ng/mL and abnormal DRE findings.

CONCLUSIONS

Six-core biopsy provided a similar cancer detection rate compared with 12-core biopsy in patients with PSA levels greater than 10 ng/mL and abnormal DRE findings. An initial approach with 6-core biopsy is reasonable in patients with a PSA level greater than 10 ng/mL and abnormal DRE findings and is advocated in those with PSA greater than 20 ng/mL and abnormal DRE findings.

Low Age Adjusted Free Testosterone Levels Correlate With Poorly Differentiated Prostate Cancer

PURPOSE

We determined the relationship between age adjusted free T, and stage, grade and the biochemical-free survival rate in patients with surgically treated prostate cancer.

MATERIALS AND METHODS

A retrospective cohort study was done between 1995 and 2001 in 333 patients treated for clinically localized prostate cancer with radical retropubic prostatectomy by a single surgeon at our institution. The study cohort consisted of 279 patients (84%) who had free T levels available. Free T was assessed by single cutoff value of 1.5 ng/dl or less, as suggested by the assay manufacturer, or by age adjusted free T. The relationship of low free T as a single cutoff value and age adjusted reference ranges with clinical and pathological measures of disease progression were assessed using the Fisher exact and Wilcoxon rank sum tests with the outcome assessed by the log rank test.

RESULTS

Using the assay manufacturer suggested single cutoff value of 1.5 ng/dl or less to define low free T 57% of patients with prostate cancer in the cohort were categorized as hypogonadal. However, using age adjusted free T reference ranges only 2.5% of patients with prostate cancer were categorized as hypogonadal, which is more logical and representative of clinically significant hypogonadism in the general population. Poorly differentiated prostate cancer was associated with low free T when measured by a single cutoff value of 1.5 ng/dl or less, or by age adjusted free T (p = 0.017 and 0.04, respectively).

CONCLUSIONS

Low age adjusted free T as well as single cutoff free T correlates with poorly differentiated prostate cancer in surgically treated patients.

Role of prostate biopsy schemes in accurate prediction of Gleason scores

OBJECTIVES

To determine whether improved prostate sampling by the extended biopsy scheme also improves the accuracy of the biopsy Gleason score (bGS). Because most prostate cancer cases are now detected at an early stage with a low prostate-specific antigen level, the bGS may be the most important factor in therapeutic decision-making. Sextant biopsy schemes had poor correlation with prostatectomy Gleason scores. Extended prostate biopsies have replaced the sextant scheme because of the former's greater cancer detection rate.

METHODS

We identified 426 patients whose biopsy and prostatectomy specimens were reviewed at our center. To minimize the effect of stage migration, all patients before 1997 were excluded. Of the 426 included patients, 221 men had undergone sextant biopsy and 205 men extended biopsy before prostatectomy. The rate of grading concordance and the effect of different variables on the concordance rate was determined.

RESULTS

The overall accuracy of the extended and sextant schemes was 68% and 48% (P <0.001), respectively. Upgrading of the bGS was significantly less likely with the extended scheme (17% versus 41%, P <0.001). The sextant biopsy was more likely to be upgraded for a bGS of 6 or less (44% versus 25%, P <0.002) and a bGS of 7 (14% versus 3%, P <0.02). On multivariate analysis, the biopsy scheme was the only independent predictor of accurate Gleason scoring (P <0.001) and age, prostate-specific antigen level, digital rectal examination findings, prostate size, clinical stage, and number of positive cores were not.

CONCLUSIONS

The use of an extended prostate biopsy scheme significantly improves the correlation between the bGS and prostatectomy Gleason score and reduces the risk of upgrading to a worse Gleason group at prostatectomy.

Classification and Regression Tree Analysis for the Prediction of Aggressive Prostate Cancer on Biopsy

PURPOSE

Prostate cancer screening allows early cancer detection but not all patients benefit from subsequent therapy. Thus, identifying patients who are likely to harbor aggressive cancer could significantly decrease the number of prostate biopsies performed.

MATERIALS AND METHODS

Data were collected on 1,563 consecutive referred men with serum PSA 10 ng/ml or less who underwent an initial prostate biopsy. Predictors of aggressive cancer (Gleason sum 7 or greater) were identified using CART analysis. Model building was done in a randomly selected training set (70% of the data) and validation was completed using the remaining data.

RESULTS

Cancer was detected in 406 men (26.1%). Gleason 7 or greater cancer was found in 130 men (8.3%). CART created a decision tree that identified certain groups at risk for aggressive cancer, namely 1) PSAD greater than 0.165 ng/ml/cc, and 2) PSAD greater than 0.058 to 0.165 ng/ml/cc or less, age greater than 57.5 years and prostate volume greater than 22.7 cc. The incidence of aggressive prostate cancer was 1.1% when PSAD was 0.058 ng/ml/cc or less in the validation set. The sensitivity and specificity of CART for identifying men with aggressive cancer were 100% and 31.8% for model building data, and 91.5% and 33.5% for the validation data set, respectively.

CONCLUSIONS

CART identified groups at risk for aggressive prostate cancer. Application of this CART could decrease unnecessary biopsies by 33.5% when only a diagnosis of high grade prostate cancer would lead to subsequent therapy.

Evidence for a biopsy derived grade artifact among larger prostate glands

PURPOSE

The PCPT has demonstrated a higher incidence of high grade (Gleason pattern 4 or greater) prostate cancers among men randomized to finasteride. One plausible explanation for this finding is that tumor grade as assigned by TRUS guided biopsy is artifactually associated with prostate volume.

MATERIALS AND METHODS

We evaluated our institutional data set of TRUS guided biopsies in the last 3 years and identified 369 cases of prostate cancer that fit the criteria of PSA less than 10 ng/ml, biopsy at our center and RP at our center. We identified risk factors for Gleason pattern 4 or greater on biopsy and then on RP specimens from the same patients using univariate and multiple logistic regression analyses. Assessed covariates included patient age, PSA and TRUS volume.

RESULTS

Risk factors for Gleason pattern 4 or greater in the biopsy specimens included age (p = 0.01), hypoechoic lesions on TRUS (p <0.001) and TRUS volume (p = 0.008). However, among RP specimens TRUS volume (p = 0.60) became nonsignificant of Gleason pattern 4 or greater on multivariable analysis. Although prostate volume was a predictor for biopsy derived high grade disease it was not predictive of true histological grade.

CONCLUSIONS

These data suggest that simply having a larger prostate results in fewer high grade cancers diagnosed at biopsy. Prostatectomy results in the same men suggest sampling artifact, as the distribution of cancer grade is not associated with prostate volume. These findings provide evidence that the increase in higher grade tumors among men in the finasteride arm of PCPT may simply result from prostate volume reduction.

Evaluation of concordance of Gleason score between prostatectomy and biopsies that show more than two different Gleason scores in positive cores

OBJECTIVES

To evaluate variables that may predict the Gleason score of radical prostatectomy specimens in patients with more than two different Gleason scores in the positive cores of their biopsy specimens.

METHODS

We reviewed the pathologic data of 98 patients who had more than two different Gleason scores in 12-site biopsy specimens. We assessed the following biopsy parameters: the greatest Gleason score on the biopsy specimen, the Gleason score of the greatest tumor percentage in the core, the Gleason score of the largest linear cancer length, and the greatest tumor ratio score (Gleason score of the greatest total tumor length of the same Gleason score/total core length of the same Gleason score). We also assessed the concordance in Gleason scores between biopsy specimens and prostatectomy specimens.

RESULTS

The greatest tumor ratio score was associated with the greatest (67%) concordance rate. The concordance of the greatest Gleason score on biopsy specimens was only 49%. When stratified into categories of well-differentiated (Gleason score 6 or less), moderate (Gleason score 7), and poorly differentiated (Gleason score 8 or more), the grade concordance rate of the greatest tumor ratio score was 73%. The grade concordance rate of the Gleason scores of the greatest tumor percentage in the core, Gleason score core with maximal tumor length, and the greatest Gleason score was 64%, 62%, and 57%, respectively.

CONCLUSIONS

If biopsy specimen results in more than two different Gleason scores in the positive cores, the greatest tumor ratio score may be the most useful variable with regard to the prediction of the final Gleason score in the radical prostatectomy specimen.

The independent impact of extended pattern biopsy on prostate cancer stage migration

PURPOSE

There are many factors impacting stage migration for prostate cancer. The number of prostate core biopsies is known to increase detection of prostate cancers. It is still unknown whether the number of biopsies is an independent predictor of tumor size. This is important as a number of studies show that tumor volume is an independent predictor of cancer progression.

MATERIALS AND METHODS

Using the University of California, San Francisco Urologic Oncology database, a retrospective review of 378 patients undergoing radical prostatectomy by a single surgeon during 2000 to 2003 was performed. Patient and tumor specific variables including age, prostate specific antigen (PSA), number of biopsies, biopsy Gleason grade, tumor volume in the surgical specimen and surgical specimen tumor grade were studied. Univariate and multivariate statistical methods including multiple and logistic regression were used to characterize patients by the number of biopsy cores. Tests of significance to identify predictors of tumor size were based on the partial F statistic and the likelihood ratio test.

RESULTS

A total of 317 eligible patients were studied, of whom 119 had 6 biopsies and 198 had more than 6 biopsies. The 2 groups of patients were evenly matched in terms of age, PSA and Gleason sum, with no statistically significant differences observed. On univariate analysis, mean tumor volume was larger for patients receiving 6 core biopsies vs greater than 6 core biopsies (3.85 vs 2.04 cc, p = 0.0009). Additionally, statistically significant differences were observed when comparing median tumor volumes, as well as excluding extremely large volume tumors. On multivariate analysis the number of biopsies performed (6 vs more than 6), was an independent predictor of tumor size (p = 0.006), controlling for primary Gleason score, Gleason sum, PSA as a continuous or categorical variable, year of biopsy and year of surgery.

CONCLUSIONS

The use of extended pattern prostate biopsy templates results in the detection of smaller volume prostate cancers, independent of PSA and Gleason grade. These biopsy templates have contributed to the downward stage migration of prostate cancer detection and may possibly contribute to the risk of over detection.

Extended 12-core prostate biopsy increases both the detection of prostate cancer and the accuracy of Gleason score

OBJECTIVE

To evaluate the effect of extended 12-core prostate biopsy in improving the detection rate of prostate cancer and increasing the accuracy of Gleason score.

METHODS

This study included 113 patients who underwent TRUS-guided lateral sextant biopsy (group I) and 176 patients who underwent extended 12-core biopsy (group II). Inclusion criteria for prostate biopsy were elevated serum PSA levels (>3.0 ng/ml) and/or suspicious digital rectal examination (DRE).

RESULTS

Clinical characteristics were similar in both groups. Cancer was detected in 28 (24.8%) and 64 (36.4%) patients in group I and II respectively, chi2=4.26, p=0.039. Among patients with cancer in group I, 14 were treated by radical prostatectomy (RP). The median Gleason sum was 6 (range 3-8) and 7 (range 5-9) for needle and prostatectomy specimens respectively. There was an agreement between the biopsy and prostatectomy Gleason sum in 7 (50%) patients while the biopsy Gleason sum was lower in 7 (50%) cases. Among patients with cancer in group II, 27 were treated by RP. The median and the range of Gleason sum was the same for needle and prostatectomy specimen (median 6, range 4-9). There was an agreement between the biopsy and prostatectomy specimen in 23 (85.2%) patients while the biopsy sum was lower than prostatectomy in 4 (14.8%) patients. The agreement between the biopsy and prostatectomy specimen was significantly higher in group II (82.5%) than group I (50%), Fisher's Exact Test, p=0.026.

CONCLUSION

Extended 12-core prostate biopsy significantly increases both the detection rate of prostate cancer and the accuracy of biopsy Gleason score.

Obtaining fresh prostate cancer tissue for research: a novel biopsy needle and sampling technique for radical prostatectomy specimens

BACKGROUND

Fresh or fresh-frozen tissue samples are preferred for molecular profiling as formalin fixation degrades intracellular nucleic acids. Radical prostatectomy (RP) specimens are a valuable source of prostate cancer tissue, but the reliance on whole-organ pathological processing for prognostication limits sampling opportunities. Few studies have addressed specific harvesting techniques using prostatectomy specimens.

MATERIALS AND METHODS

Ex vivo biopsies were performed on 23 consecutive fresh RP specimens using a purpose-designed needle. A standard sextant approach was used with an additional lateral biopsy on each side. Cores from each lobe were snap-frozen together and sections assessed by a pathologist blinded to the RP and pre-operative biopsy pathology. Comparison with pre-operative biopsies was performed using the t-test and chi(2) statistical tests. Eleven randomly selected RP specimens were further evaluated for the effects of needle tracks and margin perforation.

RESULTS

Cancer was detected in 19 of 23 specimens, giving a sensitivity of 83.6%. The average tumor involvement was 28.3% per section compared with 15.6% for pre-operative biopsies (P < 0.02). There was no statistically significant difference between the groups for either Gleason sum score concordance or tumor location concordance. In 3 of 11 cases, needle margin perforation was identified; in none of the cases did it compromise pathological assessment, although in one case a deeper block resection was required.

CONCLUSIONS

Ex vivo biopsy is a useful technique for retrieving fresh tissue whilst preserving organ morphology in RP specimens. The purpose-designed needle and harvesting technique provide good yields of cancer tissue from a high proportion of sampled prostatectomy specimens.

Gleason grading and volume estimation in prostate needle biopsy specimens: evolving issues

The Gleason grading system for prostate cancer is a powerful tool that can help choose therapy and predict outcome for patients. The clinical use and problem areas of the Gleason grading system are reviewed. The issues discussed include grade discrepancies between prostate biopsy and resection specimens, grading small foci of tumor, diagnosing and grading cribriform lesions, reporting the grade when 3 grades of cancer are present in a specimen, and assignment of grade when multiple cores of differing grades are present. Finally, differing ways of communicating tumor volume and the percentage of high-grade carcinoma in prostate biopsy cores are considered.