Effect of the Number of Core Biopsies of the Prostate on Predicting Gleason Score of Prostate Cancer

TRUS-Guided Target Biopsy for a PI-RADS 3–5 Index Lesion to Reduce Gleason Score Underestimation: A Propensity Score Matching Analysis

Background

Magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS)-guided cognitive or image fusion biopsy is performed to target a prostate imaging reporting and data system (PI-RADS) 3–5 lesion. Biopsy Gleason score (GS) is frequently underestimated compared to prostatectomy GS. However, it is still unclear about how many cores on target are necessary to reduce undergrading and if additional cores around the target may improve grade prediction on surgical specimen.

Purpose

To determine the number of target cores and targeting strategy to reduce GS underestimation.

Materials and Methods

Between May 2017 and April 2020, a total of 385 patients undergoing target cognitive or image fusion biopsy of PI-RADS 3–5 index lesions and radical prostatectomies (RP) were 2:1 matched with propensity score using multiple variables and divided into the 1–4 core (n = 242) and 5–6 core (n = 143) groups, which were obtained with multiple logistic regression with restricted cubic spline curve. Target cores of 1–3 and 4–6 were sampled from central and peripheral areas, respectively. Pathologic outcomes and target cores were retrospectively assessed to analyze the GS difference or changes between biopsy and RP with Wilcoxon signed-rank test.

Results

The median of target cores was 3 and 6 in the 1–4 core and 5–6 core groups, respectively (p < 0.001). Restricted cubic spline curve showed that GS upgrade was significantly reduced from the 5th core and there was no difference between 5th and 6th cores. Among the matched patients, 35.4% (136/385; 95% confidence interval, 0.305–0.403) had a GS upgrade after RP. The GS upgrades in the 1–4 core and 5–6 core groups were observed in 40.6% (98/242, 0.343–0.470) and 26.6% (38/143, 0.195–0.346), respectively (p = 0.023). Although there was no statistical difference between the matched groups in terms of RP GS (p = 0.092), the 5–6 core group had significantly higher biopsy GS (p = 0.006) and lower GS change from biopsy to RP (p = 0.027).

Conclusion

Five or more target cores sampling from both periphery and center of an index tumor contribute to reduce GS upgrade.

Preoperative low serum testosterone is associated with high-grade prostate cancer and an increased Gleason score upgrading

BACKGROUND

To compare histological feature of prostate cancer (PCa) according androgenic status in patients who underwent radical prostatectomy (RP).

METHODS

Between March 2007 and September 2013, we prospectively analysed 937 patients who were referred to our centre for RP. Clinical, pathological and biological data have been prospectively collected. Preoperative total testosterone (TT) and bioavailable testosterone (BT) serum determinations were carried out. The threshold for low serum testosterone was set at TT<3 ng/ml. Preoperative PSA value was registered. Gleason score (GS) and predominant Gleason pattern were determined in prostate biopsies and in prostate tissue specimens, crosschecked by two uro-pathologists.

RESULTS

Nine hundred and thirty-seven consecutive patients were included. In all, 14.9% patients had low TT in the population. An exact match between biopsy and prostate specimens in GS grading was observed for 50.6% patients (n=474). Also, 40.9% of all patients were upgraded (n=383): 45.3% (n=63) in low serum testosterone patients and 40.1% (n=320) in normal serum testosterone patients. For prostate specimens, the proportion of patients with predominant Gleason pattern 4 was higher in patients with low TT compared with normal TT (41.7% vs 29.1%, P=0.0029). In all, 20.1% were upgraded from predominant Gleason pattern 3 on biopsies specimen to predominant Gleason 4 pattern on the prostate specimen in patients with low TT, whereas 11.6% were upgraded for normal TT patients (P=0.002).

CONCLUSIONS

Low serum testosterone is an independent risk factor for predominant Gleason pattern 4 on prostate specimen after RP and for upgrading from low- to high-grade cancer between prostate needle biopsies and RP specimen. This observation should be taken into account in localised PCa management, especially for active surveillance or when a nerve-sparing approach is considered.

Pathological upgrading in prostate cancer patients eligible for active surveillance: Does prostate-specific antigen density matter?

Purpose

To evaluate prospectively the role of prostate-specific antigen (PSA) density in predicting Gleason score upgrading in prostate cancer patients eligible for active surveillance (T1/T2, biopsy Gleason score≤6, PSA≤10 ng/mL, and ≤2 positive biopsy cores).

Materials and Methods

Between January 2010 and November 2013, among patients who underwent greater than 10-core transrectal ultrasound-guided biopsy, 60 patients eligible for active surveillance underwent radical prostatectomy. By use of the modified Gleason criteria, the tumor grade of the surgical specimens was examined and compared with the biopsy results.

Results

Tumor upgrading occurred in 24 patients (40.0%). Extracapsular disease and positive surgical margins were found in 6 patients (10.0%) and 8 patients (17.30%), respectively. A statistically significant correlation between PSA density and postoperative upgrading was found (p=0.030); this was in contrast with the other studied parameters, which failed to reach significance, including PSA, prostate volume, number of biopsy cores, and number of positive cores. Tumor upgrading was also highly associated with extracapsular cancer extension (p=0.000). The estimated optimal cutoff value of PSA density was 0.13 ng/mL², obtained by receiver operating characteristic analysis (area under the curve=0.66; p=0.020; 95% confidence interval, 0.53-0.78).

Conclusions

PSA density is a strong predictor of Gleason score upgrading after radical prostatectomy in patients eligible for active surveillance. Because tumor upgrading increases the potential for postoperative pathological adverse findings and prognosis, PSA density should be considered when treating and consulting patients eligible for active surveillance.

Evaluation of D'Amico criteria for low-risk prostate cancer

OBJECTIVE

The aim of the study was to identify the risk of unfavourable disease (≥ pT3 and/or Gleason score ≥ 7) in radical prostatectomy (RP) specimens and biochemical progression-free survival (BPFS) after RP in patients with low-risk prostate cancer detected by D'Amico criteria before surgery.

MATERIAL AND METHODS

Between 2004 and 2007, 690 men underwent prostate biopsy and RP at a single university hospital. Of those, 248 patients (35.9%) had low-risk prostate cancer criteria. The endpoints of the study were detection of low-risk (pT2 and Gleason score ≤ 6) or unfavourable (≥ pT3 and/or Gleason score ≥ 7) prostate cancer, and BPFS. The risk of progression was analysed using multivariate Cox regression model and BPFS was established using Kaplan-Meier analysis.

RESULTS

The median follow-up was 60 months (1-112 months). pT3 was detected in 14.1%, and Gleason score ≥ 7 in 32.7% of patients. Unfavourable prostate cancer was detected in 37.5% of patients. Overall biochemical relapse rate was 13.6%. The estimated probability of 3-, 5- and 8-year BPFS for all study patients was 90.6%, 88.1% and 77.9%, respectively. Eight-year BPFS was 83.3% for low-risk prostate cancer and 68.2% for unfavourable prostate cancer (p = 0.007). Positive surgical margins (p = 0.0001) and postoperative Gleason score (p = 0.023) were the most significant predictors of biochemical relapse in Cox regression analysis.

CONCLUSIONS

The D'Amico criteria may underestimate potentially aggressive prostate cancer in up to 37.5% of patients. Consequently, caution is recommended when the decision concerning the treatment modality is based on D'Amico criteria alone.

Importance and determinants of Gleason score undergrading on biopsy sample of prostate cancer in a population-based study

Background

In this population-based study, we investigated the degree of concordance between Gleason scores obtained from prostate biopsies and those obtained from prostatectomy specimens, as well as the determinants of biopsy understaging.

Methods

We considered for this study all 371 prostate cancer patients recorded at the Geneva Cancer Registry diagnosed from 2004 to 2006 who underwent a radical prostatectomy. We used the kappa statistic to evaluate the Gleason score concordance from biopsy and prostatectomy specimens. Logistic regression was used to determine the parameters that predict the undergrading of the Gleason score in prostate biopsies.

Results

The kappa statistic between biopsy and prostatectomy Gleason score was 0.42 (p < 0.0001), with 67% of patients exactly matched, and 26% (n = 95) patients with Gleason score underestimated by the biopsy. In a multi-adjusted model, increasing age, advanced clinical stage, having less than ten biopsy cores, and longer delay between the two procedures, were all independently associated with biopsy undergrading. In particular, the proportion of exact match increased to 72% when the patients had ten or more needle biopsy cores. The main limitation of the study is that both biopsy and prostatectomy specimens were examined by different laboratories.

Conclusions

The data show that concordance between biopsy and prostatectomy Gleason scores lies within the classic clinical standards in this population-based study. The number of biopsy cores appears to strongly impact on the concordance between biopsy and radical prostatectomy Gleason score.

[Accuracy of prostate biopsies to evaluate tumor location in prostate cancer]

INTRODUCTION

The therapeutic approach of prostate cancer depends mainly on pathological criteria obtained through prostate biopsy. The low accuracy of prostate biopsy for Gleason grade determination is well known but its accuracy for bilateral or multifocal tumor has not been evaluated. The goal of this study was to assess the concordance between prostate biopsy and whole prostate specimen obtained after radical prostatectomy especially for bilateral and/or multifocal tumor.

METHODS

We retrospectively compared the pathological results of prostate biopsy cores to the prostate specimen in patients who underwent radical prostatectomy in our department between the 01/01/1999 and the 31/12/2008. The criteria analyzed were the Gleason score, tumor bilaterality or multifocality. The impact of the number of prostate biopsy cores was also analyzed.

RESULTS

Two hundred and five complete histological records were studied. Regarding the Gleason score overall concordance was 55%. In 38%, prostate biopsies downgraded the Gleason score. This concordance decreased with tumor differentiation (90.6% for Gleason 6 vs. 31% for Gleason greater than 7). For the tumor bilaterality, 78% of cancers affected both lobes at the definitive specimen analysis while only 49% were bilateral at prostate biopsies, achieving a concordance of 61%. Multifocal disease was observed in 36% at definitive pathology analysis with low concordance with prostate biopsies (36%). The number of biopsies increased the concordance for the Gleason score (60 to 81% for Gleason 7 and from 28 to 50% for Gleason greater than 7) and tumor location (44 to 70%).

CONCLUSION

Pathological criteria and tumor mapping obtained from prostate biopsies were not very reliable especially when the tumor was poorly differentiated. An increased number of prostate biopsy core improved the sensitivity and specificity for the Gleason score diagnostic and of the tumor mapping.

[Prostate cancer: Gleason scores correlation between biopsies and surgical gross specimen]

The Gleason score is a histopronostic criterion which gives an appraisal of prostate cancer aggressiveness and outcomes.

OBJECTIVE

The goal of this retrospective study was to assess the relationship between Gleason scores appreciated on biopsies and later on surgical gross specimen.

RESULTS

During the period of the study, 123 patients benefit of a histological diagnosis of prostate cancer recording Gleason score on biopsies and postsurgical intervention on gross specimen. After analysis of biopsies and for gross specimen the reported Gleason scores vary from 3 to 9 and the mean was 5.9 and 6.1 respectively. There was a good concordance between the Gleason scores for biopsies and gross specimen in about 32.5% of cases. We noted a difference of score of one point in 37.3% of patients and a difference of two points and more in 30% of cases. In 28.4% the Gleason scores were overestimated while in 39% they were underestimated. More than half of the patients' cohort was classified in the group of histologically moderately differentiated cancer. When grouping the patients according to the histological types well, moderately or less differentiated cancers, the Gleason scores concordance for biopsies and for gross specimen change from 32.5% up to 74.8%. The correlation can be considered good for the less differentiated cancers.

CONCLUSION

Gleason score showed some limits in the appreciation of the prediction. The grouping of patients according to the three distinct histological differentiation groups increases the concordance between the score of Gleason on biopsy specimen and gross specimen but it seems less powerful for cancers well and moderately differentiated cancers.

Predictors for clinically relevant Gleason score upgrade in patients undergoing radical prostatectomy

OBJECTIVE

To evaluate clinical predictors for Gleason score upgrade (GSU) in radical prostatectomy (RP) specimen, especially in patients with 'very' low risk PCA (T1c and biopsy Gleason score ≤6 and PSA <10 ng/ml and ≤2 positive biopsy cores and PSA density <0.15).

PATIENTS AND METHODS

402 consecutive patients undergoing RP between 2004 and 2006, including a subgroup of 62 patients with 'very' low risk PCA, were examined. Patients were categorized for clinically relevant GSU (defined as upgrade into a higher PCA risk category). Parameters including number of biopsy cores obtained, positive biopsy cores, prostate weight, PSA, DRE and pathology department were evaluated for their role as predictors. Furthermore, GSU in RP specimen was analyzed for its impact on pT-stage.

RESULTS

Clinically relevant GSU occurred in 38.1% in the whole cohort and in 32.3% in the 'very' low risk PCA subgroup. Gleason score downgrade (GSD) occurred in 4.7%. Number of biopsy cores obtained and prostate weight were independent negative predictors of GSU in all 402 patients (P = 0.02 and P = 0.03, respectively). In the 'very' low risk group, only number of biopsy cores obtained revealed as an independent negative predictor of GSU (P = 0.02). PSA, DRE, number of positive cores or pathology department were not associated to GSU. In the 'very' low risk group, GSU was related with extracapsular tumor extension (P = 0.05).

CONCLUSIONS

Clinically relevant GSU in RP specimen is still a challenging problem. Increasing the number of biopsy cores lower this risk significantly. GSD is rare and thus of minor importance for treatment decisions.

Saturation biopsy improves preoperative Gleason scoring of prostate cancer

We evaluated the differences between conventional needle biopsy (CB) and saturation biopsy (SB) techniques with regard to the prediction of Gleason score, tumor stage, and insignificant prostate cancer. Data from a total number of 240 patients were analyzed. The main group, consisting of 185 patients, was diagnosed according to a saturation prostate needle biopsy protocol (SB), by which more than 12 cores were taken per biopsy. The control group was diagnosed using CB, by which 12 or less than 12 cores were taken per biopsy (n=55). In the main group, the Gleason score of the biopsy was confirmed in 19.5%, in the control group in 23.5% according to the prostatectomy specimen (p=0.50). Upgrading after the operation was found in 56.7% in the main group and in 60% in the control group (p=0.24). Downgrading after the operation was found in 23.9% in the main group and in 16.3% in the control group (p=0.24). If the Gleason score of the postoperative specimens differed by only one point from the biopsy, we considered this a minor deviation. In the main group, 59% of the carcinomas were preoperatively classified correctly or revealed minor deviation in Gleason scores. In contrast, only 47% of the carcinomas in the control group were assessed correctly or with minor deviation in Gleason scores. Thus, the main group demonstrated a better rate of preoperative prediction in tumor grading assessed by Gleason score (p=0.05). In addition, the Gleason scores of both protocols were assigned to three groups (Gleason <7; Gleason 7; Gleason >7), and the group changes from the biopsy to the prostatectomy specimen were found to be significantly more frequent in the CB group (p=0.04). There was no significant difference between the two types of biopsy techniques regarding tumor stage or the detection of insignificant carcinomas. The advantage of the extensive prostate needle biopsy technique (SB) is a better preoperative prediction of the Gleason score as well as the risk groups with Gleason scores <7, equal to 7, or >7. Both techniques fail to detect insignificant prostate cancer.

Well-differentiated prostate cancer in core biopsy specimens may be associated with extraprostatic disease

CONTEXT AND OBJECTIVE

Accurate determination of the Gleason score in prostate core biopsy specimens is crucial in selecting the type of prostate cancer treatment, especially for patients with well-differentiated tumors (Gleason score 2 to 4). For such patients, an inaccurate biopsy score may result in a therapeutic intervention that is too conservative. We evaluate the role of Gleason score 2-4 in prostate core-needle biopsies for predicting the final pathological staging following radical prostatectomy.

DESIGN AND SETTING

Retrospective study at Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo.

METHODS

We analyzed the medical records of 120 consecutive patients who underwent radical retropubic prostatectomy to treat clinical localized prostate cancer at our institution between December 2001 and July 2006. Thirty-two of these patients presented well-differentiated tumors (Gleason score 2 to 4) in biopsy specimens and were included in the study. The Gleason scores of the core-needle biopsies were compared with the pathological staging of the surgical specimens.

RESULTS

Sixteen of the 32 patients (50%) presented moderately differentiated tumors (Gleason score 5 to 7) in surgical specimens. Eighteen patients (56%) had tumors with involvement of the prostate capsule and ten (31%) had involvement of adjacent organs. Evaluating the 16 patients that maintained Gleason scores of 2 to 4 in the pathological staging of the surgical specimens, 11 (68.7%) had focal invasion of the prostate capsule and five (31.25%) had organ-confined disease.

CONCLUSION

Well-differentiated tumors (Gleason score 2 to 4) seen in biopsies are not predictive of organ-confined 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.

Prognostic significance of Gleason score discrepancies between needle biopsy and radical prostatectomy

OBJECTIVES

Discordance between the Gleason score (GS) on needle biopsy (NB) and the GS of the radical prostatectomy (RP) specimen is a common finding. The objective of this study was to evaluate the prognostic significance of these discrepancies with respect to outcomes following RP.

METHODS

In the study, 6625 men treated by RP were categorized as having NB=RP (68.8%), NB<RP (25.0%) or NB>RP (6.2%) GS, and stratified for analyses into RP GS groups. The Kaplan-Meier method was used to analyze differences in biochemical recurrence-free survival (BRFS), and multivariate Cox analyses were performed to estimate the independent relative risk of progression associated with GS discrepancies.

RESULTS

Across multiple RP GS strata (3+4, 7, 8, 8-10), patients with a lower NB GS experienced significantly better BRFS than patients with equal NB and RP GS (all p<0.05). NB<RP GS was independently associated with better (pooled HR, 0.76, p=0.001) BRFS, within and across RP GS strata. Similarly, patients with NB>RP GS had poorer BRFS than patients with NB=RP GS across multiple RP GS strata (< or =3+3, 3+4, 7; all p<0.05). NB>RP GS was independently associated with worse (pooled HR, 1.91, p<0.001) BRFS probabilities, within and across RP GS strata.

CONCLUSIONS

Our data suggest that the GS of the NB adds additional prognostic value to the RP GS in a consistent manner that may be applicable to strategies of risk stratification and patient counseling after surgery.

Predicting the risk of patients with biopsy Gleason score 6 to harbor a higher grade cancer

PURPOSE

Prostate cancer Gleason score 3 + 3 = 6 is currently the most common score assigned on prostatic biopsies. We analyzed the clinical variables that predict the likelihood of a patient with biopsy Gleason score 6 to harbor a higher grade tumor.

MATERIALS AND METHODS

The study population consisted of 448 patients with a mean age of 59.1 years who underwent radical prostatectomy between February 2003 to October 2006 for Gleason score 6 adenocarcinoma. The effect of preoperative variables on the probability of a Gleason score upgrade on final pathological evaluation was evaluated using logistic regression, and classification and regression tree analysis.

RESULTS

Gleason score upgrade was found in 91 of 448 patients (20.3%). Logistic regression showed that only serum prostate specific antigen and the greatest percent of cancer in a core were significantly associated with a score upgrade (p = 0.0014 and 0.023, respectively). Classification and regression tree analysis showed that the risk of a Gleason score upgrade was 62% when serum prostate specific antigen was higher than 12 ng/ml and 18% when serum prostate specific antigen was 12 ng/ml or less. In patients with serum prostate specific antigen lower than 12 ng/ml the risk of a score upgrade could be dichotomized at a greatest percent of cancer in a core of 5%. The risk was 22.6% and 10.5% when the greatest percent of cancer in a core was higher than 5% and 5% or lower, respectively.

CONCLUSIONS

The probability of patients with a prostate biopsy Gleason score of 6 to conceal a Gleason score of 7 or higher can be predicted using serum prostate specific antigen and the greatest percent of cancer in a core. With these parameters it is possible to predict upgrade rates as high as 62% and as low as 10.5%.

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.

Percentage of Cancer in Prostate Biopsies as Prognostic Factor for Staging and Postoperative Biochemical Failure after Radical Prostatectomy

OBJECTIVE

To assess if the percentage of cancer in prostate needle biopsies provides independent prognostic information for predicting pathological stage and/or biochemical relapse after radical prostatectomy.

METHODS

One hundred and forty prostate cancer patients who underwent radical prostatectomy were evaluated. Preoperative parameters analyzed were patient age, PSA, clinical stage, and the information obtained from sextant biopsies (Gleason score, maximum percentage of cancer in a core, percentage of tissue with cancer in all biopsies and the number of cores positive for cancer). Univariate and multivariate analyses (logistic regression) for the dependent variables (prostate cancer, organ-confined and biochemical relapse) were performed.

RESULTS

The tumor was organ-confined in 73.6% of patients. In those patients studied for disease progression (n = 126), no biochemical recurrence was observed in 76.2%. In the multivariate analysis for organ-confined disease, the total percentage of biopsy tissue with cancer, the preoperative PSA level, the Gleason score and the clinical stage were the most accurate predictive factors of pathological stage. The multivariate analysis for the study of biochemical failure indicated that only the total percentage of biopsy tissue with cancer, the preoperative PSA level and the Gleason score were independent predictive factors. According to the logistic regression analysis for disease recurrence, 3 risk groups could be identified: low risk (less than 10% probability of disease progression), intermediate risk (30%) and high risk (more than 70%).

CONCLUSIONS

The percentage of cancer in prostate biopsy provides independent prognostic information for predicting pathological stage and the risk of biochemical failure after radical prostatectomy.

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.

Relationship between primary Gleason pattern on needle biopsy and clinicopathologic outcomes among men with Gleason score 7 adenocarcinoma of the prostate

OBJECTIVES

To examine the relationship among needle biopsy primary grade, prostatectomy grade, and postprostatectomy biochemical recurrence among men with Gleason score 7 disease.

METHODS

We identified 320 men with Gleason score 7 tumors on prostate biopsy treated with radical prostatectomy between 1991 and 2001 by a single surgeon. None of these patients had received neoadjuvant or adjuvant hormonal therapy or radiotherapy. The chi-square test and Kaplan-Meier method were used to evaluate the correlation among biopsy Gleason score, prostatectomy Gleason score, and biochemical recurrence.

RESULTS

A total of 252 (79%) and 68 (21%) men had primary Gleason pattern 3 and 4 identified on needle biopsy, respectively. Of the patients with Gleason pattern 3 + 4 tumors on biopsy, 24% were upgraded to primary pattern 4 or more on final pathologic analysis. Of the patients with Gleason pattern 4 + 3 tumors on biopsy, 47% were downgraded to primary pattern 3 or less on final pathologic analysis. The actuarial risk of biochemical prostate-specific antigen recurrence was significantly lower among patients with Gleason pattern 4 + 3 on biopsy, if the prostatectomy Gleason score was downgraded to 3 + 4 or less (P = 0.03).

CONCLUSIONS

Approximately 47% of men with a diagnosis of Gleason pattern 4 + 3 on needle biopsy are downgraded at radical prostatectomy and will have biochemical prostate-specific antigen recurrence-free outcomes similar to patients originally diagnosed with Gleason pattern 3 + 4 adenocarcinoma. This group of patients may benefit from definitive treatment such as radical prostatectomy for management of their disease.

Correlation of Gleason scores between needle-core biopsy and radical prostatectomy specimens in patients with prostate cancer

BACKGROUND

The histologic grade of a prostate needle-core biopsy specimen can determine whether a patient with prostate cancer is a candidate for radical prostatectomy or other treatment. Incorrect histologic grading can result in inappropriate treatment and possible liability. Thus, we conducted this study to determine the histologic-grading accuracy of prostate cancer needle-core biopsy specimens.

METHODS

Fifty-two patients with localized prostate cancer treated with radical prostatectomy were included in the study. The overall correlation between Gleason scores for needle-biopsy and prostatectomy specimens was evaluated by analyzing the following parameters: biopsy-core number; accurate biopsy-core length; prostate volume; and preoperative, serum prostate-specific antigen (PSA) level. A "downgrade" was defined as the Gleason score for the prostatectomy specimen being greater than that for the biopsy specimen, whereas an "upgrade" was defined as the converse.

RESULTS

No difference in Gleason scores was noted for 31% of specimens, whereas a downgrade was noted for 40%, and an upgrade for 29%. The accuracy of Gleason scores for biopsy specimens taken by the sextant systemic-biopsy method increased when specimens were >15 mm in length. No correlation was noted between difference in Gleason scores and biopsy-core number, prostate volume, and preoperative serum PSA level.

CONCLUSION

The accuracy of Gleason scores determined by needle biopsy in patients with prostate cancer seems to be unreliable. Therefore, further evaluation of patients is necessary. No correlations were noted between biopsy-measured errors in Gleason score and biopsy number, prostate volume, or preoperative serum PSA level.

LIMITATIONS OF BIOPSY GLEASON GRADE: IMPLICATIONS FOR COUNSELING PATIENTS WITH BIOPSY GLEASON SCORE 6 PROSTATE CANCER

PURPOSE

We examined the implications of underestimating Gleason score by prostate biopsy in patients with biopsy Gleason 6 prostate cancer with respect to adverse pathological findings and biochemical recurrence after radical prostatectomy.

MATERIALS AND METHODS

We retrospectively reviewed clinical and pathological data on a cohort of 531 patients with Gleason score 6 on prostate biopsy who underwent radical retropubic prostatectomy between June 1992 and January 2002. Patients were excluded if they received neoadjuvant androgen deprivation. Concordance between biopsy and radical prostatectomy Gleason score was examined. A comparison was made with respect to final radical prostatectomy specimen pathology and the risk of biochemical recurrence between cases that remained Gleason 6 and those with a final grade of 7 or greater.

RESULTS

A total of 451 patients were included in the analysis. Mean followup was 55.1 months (range 12 to 123.4). Of the patients 184 (41%) had a Gleason score of 7 or greater after a review of the entire prostate, while 37 (8%) had a score of less than 6 and 230 remained with Gleason 6. Patients who were under graded were more likely to have extraprostatic extension (22% vs 4%, p <0.01), seminal vesicle invasion (9% vs 2%, p <0.01) and biochemical recurrence (10% vs 3%, p <0.01) compared to those who remained with Gleason score 6.

CONCLUSIONS

Gleason grade on needle biopsy is an inexact predictor of the final grade following radical prostatectomy. Patients with biopsy Gleason score 6 who are under graded are at significantly higher risk for adverse pathological features and biochemical recurrence than patients who remain with Gleason score 6 or less on final pathology findings.

Accuracy of gleason grading by practicing pathologists and the impact of education on improving agreement

The aims of this study were to evaluate the accuracy of Gleason grading for prostatic adenocarcinoma among practicing pathologists in Japan and to determine the influence of education on this accuracy. Using a case-oriented approach, 16 hematoxylin and eosin-;stained glass slides with consensus scores established by 4 urologic pathologists were reviewed by 91 pathologists, divided into 2 groups. In group A, average agreements with consensus scores before and after an educational lecture were 55.7% (n = 17) and 68.4% (n = 25), and average kappa values were 0.43 and 0.67, respectively. Twelve pathologists reviewed slides twice in a different order, with average agreements of 59.5% and 77.6%, and average kappa values of 0.48 and 0.69 before and after the lecture, yielding a statistically significant improvement. In group B, the average agreement before providing an atlas with a tutorial was 61.3% (n = 61), and the kappa value was 0.44. In the second round, the average agreement was 74.5% (n = 39), and the kappa value was 0.68. Among 39 pathologists who reviewed slides twice, the average agreement in the first round was 58.8%, and the kappa value was 0.42. Improvement of both the average agreement and the kappa value were statistically significant. The average improvement in kappa values among participants who reviewed slides twice was 0.22 in group A and 0.27 in group B, a difference that is not statistically significant. Combining both groups, the incidence of concordant scores for 16 cases rose from 58.9% to 75.4%, an average increase of 16.5%. The undergrading of score 5-7 lesions was significantly reduced, from 36.3% to 14.2%. With respect to demographic factors, pathologists signing out more than 5000 cases per year showed a better agreement than those with more than 1000 cases per year (48.9% versus 78.8%; P = 0.031). These results indicate that the general agreement of Gleason scores among practicing pathologists in Japan was comparable with those in the Western countries as reported in the literature. Although this requires further improvement, both the lecture and the printed material had a similar influence on the degree of improvement.

Contemporary pathology of prostate cancer

In less than 20 years since the introduction of serum PSA and the spring-loaded 18-gauge prostatic biopsy needle, pathologists have adjusted to the limited tissue requirements of narrow needle specimens to apply criteria for diagnosis and grading of prostate cancer, borrowing from lessons learned from radical prostatectomies. Substantial gains have been made during this period in the understanding of precancerous lesions, mimics of malignancy, the criteria for minimal cancer, variants of cancer, and treatment-induced changes. The light microscopic findings remain the criterion standard for diagnosis against which all new techniques should be measured. Numerous findings have proven to be of value, including simple quantitation of histopathologic features, cancer volume, perineural invasion, and others.

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

OBJECTIVE

To identify the zonal location of prostate cancers before surgery, by analysing the mapping of ultrasonography-guided systematic sextant biopsies for differences between cancers located in the transition zone (TZ) and peripheral zone (PZ); and to compare the correlation between Gleason scores of needle biopsies and those of radical prostatectomy (RP) specimens.

PATIENTS AND METHODS

In all, 186 patients with TZ (46) and PZ cancers (140) underwent ultrasonography-guided systematic sextant biopsy and RP at the same institution. The clinical and pathological characteristics, and the anatomical location of positive biopsies, were determined and compared using t-tests and chi-square tests. Differences between Gleason scores of needle biopsies and those of RP specimens were evaluated and compared by Cohen kappa testing.

RESULTS

TZ cancers had a significantly lower rate of positive biopsies in the middle (63% vs 80%) and base (50% vs 80%) of the prostate than had PZ cancers. Positive biopsies were exclusively obtained from the apex in 19.6% of TZ and 5% of PZ cancers (P = 0.002). There was exact agreement between Gleason scores of needle biopsies and those of RP specimens in 15.2% of TZ (kappa = 0.02) and 55% of PZ cancers (kappa = 0.25), respectively.

CONCLUSION

Compared with PZ cancers, TZ cancers had a different anatomical pattern of positive biopsies, with lower rates in the middle and base of the prostate. The finding of positive biopsies exclusively in the apex favoured prostate cancer located in the TZ. Furthermore, the correlation between needle biopsy Gleason scores and those of the RP specimens was clearly lower in TZ cancers.

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

PURPOSE

We examined the concordance of Gleason scores in prostate needle biopsy specimens and the corresponding radical retropubic prostatectomy specimens in a cohort of patients grouped according to the number of cores obtained during diagnostic needle biopsy.

MATERIALS AND METHODS

We reviewed clinical and pathological data on a cohort of 466 men diagnosed with localized prostate cancer by needle biopsies who underwent radical retropubic prostatectomy between January 1, 1990 and July 31, 2001. Two study groups were identified, including 126 patients diagnosed with prostate cancer by extended needle biopsies (10 or more cores) and 340 diagnosed with cancer by nonextended needle biopsies (9 or fewer cores). Mean age was 60 years and median prostate specific antigen was 5.8 ng./ml. The median number of cores in the extended and nonextended biopsy groups was 12 and 6, respectively. The concordance of Gleason score in the needle biopsy and prostatectomy specimens was compared and correlated with the number of cores on needle biopsy.

RESULTS

In the whole cohort 311 patients (67%) had identical Gleason scores on the needle biopsy and prostatectomy specimens, while 53 (11%) were over graded and 102 (22%) were under graded on needle biopsy. In patients who underwent extended needle biopsies the accuracy rate for Gleason scoring was 76% with 10% over and 14% under graded. The highest accuracy rates were in patients with 13, 14 and 16 cores (89%, 87% and 100%, respectively). No patients in the extended needle biopsy group had a discrepancy of more than 2 Gleason units in grade in the biopsy and surgical specimens. In those who underwent nonextended needle biopsies the accuracy rate for Gleason scoring was 63% with 12% over and 25% under graded. There were significantly different rates of accuracy (p = 0.008) and under grading (p = 0.01) in the 2 needle biopsy groups. Patients with a needle biopsy Gleason score of less than 7 had significantly higher concordance with the prostatectomy Gleason score when extended biopsies were done compared with nonextended biopsies (p = 0.001).

CONCLUSIONS

Prostate cancer grading by extended needle biopsy is a better predictor of the final Gleason score than nonextended needle biopsy, as determined by radical prostatectomy histological evaluation. Therefore, extended prostate needle biopsy provides better guidance to determine the appropriate treatment in patients with prostate cancer.

Gleason score on biopsy: is it reliable for predicting the final grade on pathology?

OBJECTIVE

To assess the correlation of the Gleason score on biopsy and the final pathology after radical prostatectomy (RP) for prostate adenocarcinoma.

PATIENTS AND METHODS

In a retrospective analysis within a tertiary-care centre, the charts of 537 patients who had undergone radical prostatectomy from April 1989 to November 2000 were reviewed. The RPs were undertaken in one institution; 167 biopsies were taken and interpreted in the referring centres, and 355 were taken and interpreted in the authors' institution by up to 15 pathologists. All the final pathology specimens were interpreted by the same group of pathologists. The main outcome measures were: the pathological report of the biopsy including the primary and secondary Gleason grade; the final pathological grade (primary and secondary); the margin status; and the identification of the pathologist for the biopsy and final pathology.

RESULTS

In all, 390 patients had inclusion criteria (the Gleason grade before and after RP) available. For the individual scores 38.2% of tumours were undergraded, 32.6% overgraded and only 29.2% had identical grading in preoperative biopsies and final specimens. When grouped into more meaningful categories (Gleason 2-4, 5-6, 7 and 8-10) the correlation improved, with 48.5% of patients remaining in the same group after RP. For 39 patients the same pathologist assessed the biopsy and final specimen; in these cases individual scores were identical in 49% and group scores were identical in 64%.

CONCLUSION

Gleason grading of the prostate biopsy remains a poor predictor of pathological outcome. Assessment by the same pathologist reduces the discrepancy but over half the patients are under- or overgraded on final pathology. Clinicians should be aware of these limitations when using the biopsy Gleason grade in decision making.

The role of transrectal ultrasound in diagnosing prostate cancer

The availability of the prostate-specific antigen test to screen for prostate cancer has caused a significant workload burden for urologists and radiologists alike. Prostate cancer is common in our aging population and most cancers are now definitively detected by transrectal ultrasound (TRUS)-guided prostatic needle biopsy. TRUS alone has limited potential to identify prostatic cancer because of frequent multifocality of cancer within the prostate, the variable sonographic appearance of prostatic tumors, the poor specificity of focal ultrasonic abnormalities, and the substantial percentage of isoechoic prostate cancers (which cannot be differentiated from adjacent benign tissues with imaging). Developments in TRUS equipment over the past decade include the use of color and power Doppler, higher frequencies, broad bandwidth technologies, and harmonic, contrast harmonic, and pulse inversion imaging. All of these improvements may enhance detection of subtle focal sonographic abnormalities within the prostate. Ultrasonic contrast agents can aid the visualization of subtle alterations in prostatic echotexture by highlighting changes in microvasculature. It is possible that Doppler techniques and contrast agents have the potential to reveal prognostic information about cancer in individual patients.

Does site-specific labelling and individual processing of sextant biopsies improve the accuracy of prostate biopsy in predicting pathological stage in patients with T1c prostate cancer?

OBJECTIVE

To evaluate whether individual labelling and processing of the sextant of origin improves the accuracy of prostate biopsy in predicting the final pathological stage after radical prostatectomy in patients with T1c prostate cancer.

PATIENTS AND METHODS

The charts of 386 patients treated for prostate cancer by radical prostatectomy between January 1996 and June 1999 were reviewed. In all, 124 patients fulfilled the following inclusion criteria: no abnormality on digital rectal examination (DRE) or transrectal ultrasonography, a prostate specific antigen (PSA) level before biopsy of < or = 20 ng/mL, and prostate cancer diagnosed after one set of random sextant biopsies, with the cores being submitted in six separate containers individually labelled for the sextant of origin.

RESULTS

Within this series of patients with a low tumour burden, the preoperative PSA, biopsy Gleason score and unilateral vs bilateral involvement were not significant predictors of disease extension. The percentage of positive cores and the number and topography of positive sextants were both statistically significant predictors of organ-confined disease. Although these two variables appeared to be statistically equivalent on a first analysis in the overall series, a subgroup of patients was identified who benefited from the complete topographical information, i.e. those 52 (42%) patients with a Gleason score of < 7, 25-75% positive biopsies and < or =3 positive sextants.

CONCLUSION

These results support the individual labelling of biopsy cores in selected patients with a normal DRE and a moderately elevated PSA, as it helps to better predict the final pathological stage. This substantial benefit outweighs the additional effort by the pathologist.

Indicators of pathologic stage of prostate cancer and their use in clinical practice

Pathologic stage is the most reliable means of predicting the likelihood of curable prostate cancer at the time of definitive treatment. Its prediction is of the greatest importance to individuals with clinically localized disease, principally because of the therapeutic and prognostic implications. Multivariate models integrating variables that can be derived from clinical and pathologic assessment have been shown to be reliable and useful in urologic practice. Among these variables, the combination of clinical stage, serum PSA, and biopsy Gleason score provides reliable assessment of the risk for extraprostatic disease that can be used readily for counseling individual patients. Other biopsy-derived parameters may contribute additional information, but their value in multivariate analysis has not been validated in a multi-institutional setting. The development of new prognostic markers is a priority objective in current research to distinguish patients in whom cancer cannot be controlled by surgical treatment. For patients undergoing radical prostatectomy, definitive pathologic stage certainly will remain an important prognostic factor; therefore, clinical practice will continue to be determined by its accurate prediction.

[Percentage of tumor in prostatic biopsy cylinders as prognosis factor of organ-limited disease in candidates for radical prostatectomy]

The present study analyzes the prognostic influence of tumor percentage in cylinders of prostatic biopsy in this patient group.

MATERIAL AND METHODS

Retrospective study of 68 patients with a diagnosis of adenocarcinoma, clinical stage T1-T2 who had undergone a radical prostatectomy from May 1997 to october 2000. Following preoperative parameters were analyzed: age, PSA, clinical staging, Gleason and six cylinders of ultrasonography-leaded transrectal prostatic biopsy, studying the amount of positive biopsies, the tumor percentage of the total amount of biopsies and the maximum percentage of tumor in one cylinder. Univariate (square-Chi, Student t) and multivariate (multiple logistic regression) analysis are performed in order to study the relationship of these parameters with the presence or not of an organ-located disease.

RESULTS

An organ-located disease was shown at 44 patients through the piece of radical prostatectomy. The univariate analysis gave all studied parameters, except age, a prognostic value of the existence or not of an organ-located disease. In the multivariate analysis only the total percentage of biopsy tumors (p = 0.0002) and PSA (p = 0.005) behaved as independent prognostic factors.

CONCLUSION

Tumor percentage in prostatic biopsy seems to be a factor with a high predictive value of an organ-located disease, possibly because it is an index of tumoral volume.

Discrepancies between Gleason scores of needle biopsy and radical prostatectomy specimens

The purpose of this study was to determine the accuracy of Gleason scores in prostate needle biopsy diagnosis and to investigate factors affecting the accuracy of the tumor grade. A single pathologist reviewed 116 sets of prostate cancer biopsies and radical prostatectomy specimens. The following factors were examined to determine their effect on the accuracy of the biopsy Gleason scores: (i) relative tumor differentiation; (ii) pathological stage; (iii) amount of tissue in the biopsy specimen; (iv) amount of cancer tissue in the biopsy specimen; (v) tumor heterogeneity; (vi) clinical findings (prostate specific antigen value and digital rectal examination); and (vii) interobserver variability. In 53 cases the Gleason score of biopsy specimens was identical to the score of prostatectomy specimens (45.7%). Fifty-four cases (46.6%) of biopsy specimens were undergraded. The most common discrepancy was diagnosis of well-differentiated carcinoma in the biopsy but diagnosis of moderately differentiated tumor in the corresponding prostatectomy specimen. This discrepancy occurred when the amount of tumor in the biopsy was 3 mm or less. Biopsy and prostatectomy results showed less agreement when the original biopsy tumor grade rendered by nine different pathologists was used, suggesting that interobserver variability can adversely affect the accuracy of tumor grade. Clarifying the histologic criteria for distinguishing each grade, especially between Gleason grades 2 and 3, is important for accurate grading.

Prostate biopsy grading errors: a sampling problem?

Potential reasons for discordance between the Gleason score in biopsies and surgical specimens are: 1) pathological interpretation bias, and 2) sampling effects. The importance of sampling effects in grading errors was examined in a series where the number of biopsy cores obtained was high. Biopsies were obtained using a technique whereby 18 directed cores were systematically obtained and mapped out within the gland. Gleason scores from biopsies and matched prostatectomy specimens were compared among 28 consecutive patients with localized prostate cancer. A pooled database from 10 series (n = 2,687) served as a baseline for comparison in the accuracy of Gleason score grading. With the present biopsy technique, an exact Gleason score match was achieved in 57% of cases, compared with the pooled database (PD) mean of 42% (P = 0.055), and was within 1 point in 93% of cases compared with 78% (PD) (P = 0.029). Upgrading of biopsies was seen in 35% of cases, compared with 43% (PD) (P = 0.19). With respect to Gleason score 7, an exact match was present in 78% of cases, compared with 63% (PD) (P = 0.17), and upgrading was 0%, compared with 20% (PD) (P = 0.07). The data suggest a significant reduction in grade errors by minimizing sampling effects, one that it is of the same order of magnitude as the reduction achieved from consensus pathologic evaluation. In our study, seven patients (25%) would have had their cancers missed altogether with sextant biopsies. Sampling effects may contribute significantly to grading errors in prostate needle biopsies, although a larger study is needed to confirm this. A methodology which adopts a higher number of cores combined with a consensus pathologic evaluation could potentially reduce grading errors substantially. The optimal number of cores remains to be determined in a larger study. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 326-330 (2000).

Patterns of prostate cancer biopsy grading: trends and clinical implications

The predictive value of Gleason grading from prostate needle biopsy was examined and the patterns of grade discordance with surgical specimens are discussed in terms of their clinical implications. Gleason scores from biopsy and matched radical prostatectomy specimens were compared in 428 consecutive patients. Patterns of concordance were examined with respect to numerical agreement as well as to whether differences result in a change in group assignment with respect to Gleason score group 2-4, 5-6, 7, and 8-10. The coefficient of agreement, kappa, and accuracy were used to measure predictive value. An exact Gleason score match was present in 41% of the cases, while 48% were undergraded and 17% overgraded. With respect to group assignment, 51% remained unchanged while 35% were undergraded and 14% overgraded. Kappa analysis yielded a value of 0.26, which represents a poor agreement beyond chance. A Gleason score of 5-6, 7, or 8 was reproduced in 52%, 53%, and 58% of cases, respectively. A systematic bias toward progressive undergrading of more well-differentiated cancers and overgrading of more poorly differentiated cancers on biopsy is suggested by the data. A pooled analysis with nine additional series (n = 2,687) confirms this conclusion. No correlation was found between the amount of tumor in the biopsy specimen and grade discordance. Biases in pathologic interpretation and sampling effects are suggested as responsible for grade discordance. Predictable differences exist between the histologic grade in prostate needle biopsies and the surgical specimen. Clinical staging of organ-confined prostate cancer should include the likelihood of histologic upgrading or downgrading when used to stratify patients for clinical trials, in comparing results among therapies based on biopsy grading and when recommending a radical therapy. Developing a methodology which reduces both sampling effects and pathologic interpretation bias would likely result in significantly improved accuracy of Gleason grading of prostate biopsies. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 305-311 (2000).

Should a Gleason score be assigned to a minute focus of carcinoma on prostate biopsy?

The grading system for prostate carcinoma devised by Gleason is a strong prognostic indicator. The primary and secondary patterns are combined to give a tumor score, referred to as Gleason score or sum. Gleason scores on biopsy correlate with the prostatectomy Gleason scores, and in combination with pretreatment serum prostate-specific antigen and digital rectal examination results, predict tumor stage and lymph node status. However, when only a minute focus of tumor is present on biopsy, the Gleason score is assigned by doubling the Gleason pattern. The goal of this study was to determine if a Gleason score assigned to a minimal focus of adenocarcinoma had predictive value. Paired biopsies and prostatectomy specimens from 963 cases of men with clinically localized prostate cancer were examined. Minimal tumor on biopsy was defined as less than 1 mm or 5% involvement of one biopsy core; excluded from this definition were biopsies where two Gleason patterns could be identified and/or tumor was seen on more than one biopsy core. Terms often used to describe these lesions include "single minute focus of carcinoma" or "adenocarcinoma, too small to give a Gleason grade." One hundred five cases (10.9%) met the above criteria for minimal carcinoma. The correlation of Gleason scores between biopsies and prostatectomy specimens overall was good with exact agreement for 57% of cases and a difference of +/-1 unit in 92% of cases. The correlation for the minimal tumors on biopsy and prostatectomy was slightly worse with exact agreement in 52.4% (55 of 105) and a difference of +/-1 unit in 87.6% (92 of 105). The majority of minimal tumors (83.8% or 88 of 105) were assigned a Gleason score of 6. A total of 31.8% of these 88 cases were upgraded and 5.7% were downgraded. Multivariate analysis on all cases looking for predictors of tumor stage found biopsy Gleason score, perineural invasion, pretreatment prostatic-specific antigen, and digital rectal examination all predicted higher tumor stage with odds ratios of 1.86 (95% confidence interval [CI], 1.53-2.27; p = 0.0001), 2.06 (95% CI, 1.43-2.95; p = 0.0001), 1.08 (95% CI, 1.05-1.11; p = 0.0001), and 1.41 (95% CI, 1.04-1.91; p = 0.0289), respectively. In a model restricted to the 105 cases with minimal carcinoma, pretreatment prostatic-specific antigen was the only independent predictor of higher tumor stage with an odds ratio of 1.15 (95% CI, 1.01-1.31; p = 0.0380); Gleason score was not found to significantly predict higher tumor stage (odds ratio, 1.156; p = 0.6680). The results of this study confirm that biopsy Gleason score in most cases predicts prostatectomy Gleason score and tumor stage. However, for cases with minimal tumor on biopsy, the assigned Gleason score did not predict tumor stage. To properly convey this uncertainty to clinicians, a cautionary note should accompany Gleason scores derived from a minimal focus of carcinoma.

Diagnosis of prostate cancer in needle biopsies after radiation therapy

Interpretation of postirradiation needle biopsies is a major diagnostic challenge for the pathologist because of substantial radiation-induced changes in benign and malignant prostatic tissue. Reports that have systematically evaluated the histopathologic findings in postirradiation needle biopsies are limited. In this study, we evaluated 46 histologic features in 29 postirradiation needle biopsy specimens from 29 patients. All patients had recurrent cancer on needle biopsies after external beam radiation, and all subsequently underwent salvage radical prostatectomy and bilateral pelvic lymphadenectomy. Patient age ranged from 57 to 78 years (mean, 61 years). The interval from radiation therapy to biopsy ranged from 1.0 to 17 years (mean, 3.9 years). Histologic features that were helpful in the diagnosis of cancer after radiation therapy included infiltrative growth, perineural invasion, intraluminal crystalloids, blue mucin secretions, the absence of corpora amylacea, and the presence of coexistent high-grade prostatic intraepithelial neoplasia. Benign glands usually showed nuclear enlargement (86%) and prominent nucleoli (50%), and therefore, these cytologic features alone were not reliable for the diagnosis of cancer after irradiation. Postirradiation needle biopsies underestimated the prostatectomy Gleason grade in 35% of cases and overestimated it in 14% of cases; these results were similar to published reports from patients not receiving radiation therapy. There was a major discrepancy in degree of radiation effect between radical prostatectomy and biopsies. Moderate or severe radiation effect on cancer was present in 48% of needle biopsy specimens, whereas 94% of radical prostatectomy specimens had no or minimal radiation effect on cancer when the areas with the least amount of radiation effect were chosen for quantification. These findings indicate that quantification of radiation effect in needle biopsy specimens was inaccurate and potentially misleading. Conversely, Gleason grade in postirradiation needle biopsy specimens appeared to provide useful predictive information and should be reported.

Treatment changes in prostatic hyperplasia and cancer, including androgen deprivation therapy and radiotherapy

Substantial and characteristic changes occur in the microscopic appearance and immunophenotype of the hyperplastic prostate and adenocarcinoma following androgen deprivation therapy and radiotherapy. These changes are rarely seen in untreated cancer, and in the authors' opinion, the combinations of features following therapy are sufficiently distinctive to warrant recognition. Pathologists must be aware of these distinct changes because of the reliance placed on nuclear and nucleolar size in the identification of prostate cancer, particularly in small specimens and lymph node metastases.

Prostate biopsy interpretation. Current concepts, 1999

Needle biopsy of the prostate has a pivotal role in the diagnosis of prostate cancer and the prediction of outcome. Strategies for sampling the prostate are being refined, which will increase the diagnostic yield. In combination with other clinical factors, the pathologic findings obtained from the biopsy specimen provide enhanced predictive accuracy for stage and individual outcome.

Correlation between Gleason score of needle biopsy and radical prostatectomy tissue

Gleason score has been identified as an important variable to predict disease extent and biologic behaviour of prostate cancer. However, the correlation between Gleason score of needle biopsy and surgical specimen is often poor. We studied 72 patients who underwent needle biopsy and radical prostatectomy to correlate Gleason score with PSA, clinical and pathological tumour stage. Only 47.2% of Gleason scores were identical in the biopsy and specimens, 37.5% were undergraded and 15.2% were overgraded. Correlations between clinical and pathological stage were identical in 30.5% of patients, 61.1% of patients were understaged and 8.3% overstaged. In conclusion, accuracy of clinical staging and grading of prostate cancer is low. Although the Gleason score on needle biopsy might be useful to predict the final stage and grade, correlation with surgical specimen is poor.

Correlação entre a graduação histológica de biópsias e do espécimen cirúrgico em câncer da prostata

Foram estudados, retrospectivamente, os prontuários de 120 pacientes com câncer localizado da próstata nos estádios clínicos T1, T2 e T3a e que foram submetidos a 1infadenectomia ilíaca e a cirurgia radical da próstata. Todos haviam sido graduados pela escala de Gleason através de biópsias da próstata guiadas pela ultra-sonografia transretal. Correlacionamos a graduação histo1ógica destas biópsias da próstata com a graduação final obtida no exame da peça cirúrgica correspondente e obtivemos exata concordância em 39 pacientes (32,50%). Ao considerarmos a concordância de ± 1unidade, observamos concordância de resultado em 81 pacientes (67,50%). A subgraduação histológica das biópsias prostáticas foi encontrada em 75 pacientes (62,50%) dos casos.

Repeat transrectal ultrasound-guided prostate biopsy: a strategy to improve the reliability of needle biopsy grading in patients with well-differentiated prostate cancer

OBJECTIVES

Gleason grade from prostate needle biopsy (PNB) specimens is important in guiding therapeutic decision making in patients with localized prostate cancer. Recent data from our institution suggest a significant discordance between Gleason grading from PNB versus the actual pathologic grade at radical prostatectomy (RRP). Of most concern is that a substantial proportion of patients with Gleason score of 6 or less from PNB actually have Gleason score of 7 or more at RRP. Under classic measurement theory, one useful way to improve the reliability of an inherently unreliable test is to repeat it. We investigated this strategy in an effort to reduce undergrading errors.

METHODS

The control group of patients (n = 51) from our neoadjuvant androgen deprivation protocol was used as the test (two-biopsy) group in this study. These patients underwent two separate PNBs before RRP. We used the highest Gleason score from the two biopsies in these patients and compared the error rates with a concurrent group of patients treated at our institution (n = 226) who had only one set (single-biopsy group) of prostate biopsies. All pathologic slides were reviewed at our institution. Any PNB grade of 6 or less that was scored as 7 or more on final pathology was considered significant.

RESULTS

Mean age, prostate-specific antigen levels, and stage distribution were not significantly different between these two groups. In the single-biopsy group, 165 patients had PNB Gleason score of 6 or less. Of these patients, 63 (38%) had final pathologic grade of 7 or more. In the two-biopsy group, 37 patients had PNB Gleason score of 6 or less. Of these patients, only 7 (19%) had final pathologic grade of 7 or more (P = 0.04).

CONCLUSIONS

Prostate rebiopsy minimizes the inherent unreliability of PNB derived grade and should be considered for patients in whom watchful waiting or nomogram-based therapy has been selected.

Accuracy of biopsy Gleason scores from a large uropathology laboratory: use of a diagnostic protocol to minimize observer variability

OBJECTIVES

To examine the correlation of biopsy Gleason scores with radical prostatectomy specimens from a laboratory that uses protocols designed to minimize observer variability. This protocol mandates consensus case review of all nonbenign cases.

METHODS

Between August 24, 1993 and June 26, 1997, 106 patients who underwent radical prostatectomy at Johns Hopkins Hospital, Baltimore, Maryland had their prostate cancer diagnosed and graded at one laboratory (DIANON Systems). We analyzed the Gleason scores from the biopsy and radical prostatectomy specimens.

RESULTS

Exact correlation existed between biopsy and radical prostatectomy Gleason scores for 72 (68%) cases; 103 (97%) correlated within 1 grade, all cases correlated within 2 grades; 26 (25%) biopsies were undergraded and 8 (8%) were overgraded. Positive predictive values for biopsy Gleason scores 5, 6, and 7 were 66%, 67%, and 71%, respectively. Grouped Gleason scores (well differentiated [2 to 4], moderately differentiated [5, 6], moderately to poorly differentiated [7], and poorly differentiated [8 to 10]) correlated exactly for 74 (70%) cases and within 1 group for all cases. Patient age, digital rectal examination results, total number of positive cores, and maximum percentage of tumor on biopsy did not affect correlation, but prostate-specific antigen (PSA) levels did affect correlation (exact correlation 96% when the PSA level was less than 5 ng/mL; 50% when the PSA level was 11 ng/mL or greater, P <0.01).

CONCLUSIONS

The combination of experience and the protocol described minimizes intra- and interobserver variability, thereby improving the predictive value of biopsy Gleason grading. Biopsy and radical prostatectomy Gleason scores correlate more poorly when the PSA level is high (11 ng/mL or greater) than when the PSA level is low (less than 5 ng/mL).

Minimal criteria for the diagnosis of prostate cancer on needle biopsy

Increased clinical screening of men at risk for prostate cancer, and the realization of the benefits of performing multiple biopsies per prostate, have facilitated early detection of malignancy, while presenting the pathologist with a growing array of diagnostic findings. Interpretation of these findings requires discussion of the minimal criteria required for the diagnosis of cancer on needle biopsy within a wide spectrum of related histologic findings. This spectrum includes small acinar proliferations suspicious for but not diagnostic of cancer, benign mimics of cancer, the preinvasive entity of high-grade prostatic intraepithelial neoplasia, and various treatment effects. Clinical implications of these findings and other prognostic factors are detailed.