Discrepancy Between Local and Central Pathological Review of Radical Prostatectomy Specimens

Local Extent of Prostate Cancer at MRI versus Prostatectomy Histopathology: Associations with Long-term Oncologic Outcomes

Background It is unknown how the imperfect accuracy of MRI for local staging of prostate cancer relates to oncologic outcomes. Purpose To analyze how staging discordances between MRI and histopathologic evaluation relate to recurrence and survival after radical prostatectomy. Materials and Methods Health Insurance Portability and Accountability Act-compliant retrospective analysis of preprostatectomy T2-weighted prostate MRI (January 2001 to December 2006). Extraprostatic extension and seminal vesicle invasion were assessed by using five-point Likert scales; scores of 4 or higher were classified as positive. Biochemical recurrence (BCR), metastases, and prostate cancer-specific mortality rates were estimated with Kaplan-Meier and Cox models. Results A total of 2160 patients (median age, 60 years; interquartile range, 55-64 years) were evaluated. Among patients with histopathologic extraprostatic (pT3) disease (683 of 2160; 32%), those with organ-confined disease at MRI (384 of 683; 56%) experienced better outcomes than those with concordant extraprostatic disease at MRI and pathologic analysis: 15-year risk for BCR, 30% (95% CI: 22, 40) versus 68% (95% CI: 60, 75); risk for metastases, 14% (95% CI: 8.4, 24) versus 32% (95% CI: 26, 39); risk for prostate cancer-specific mortality, 3% (95% CI: 1, 6) versus 15% (95% CI: 9.5, 23) (P < .001 for all comparisons). Among patients with histopathologic organ-confined disease (pT2) (1477 of 2160; 68%), those with extraprostatic disease at MRI (102 of 1477; 7%) were at higher risk for BCR (27% [95% CI: 19, 37] vs 10% [95% CI: 8, 14]; P < .001), metastases (19% [95% CI: 6, 48] vs 3% [95% CI: 1, 6]; P < .001), and prostate cancer-specific mortality (2% [95% CI: 1, 9] vs 1% [95% CI: 0, 5]; P = .009) than those with concordant organ-confined disease at MRI and pathologic analysis. At multivariable analyses, tumor extent at MRI (hazard ratio range, 4.1-5.2) and histopathologic evaluation (hazard ratio range, 3.6-6.7) was associated with the risk for BCR, metastases, and prostate cancer-specific mortality (P < .001 for all analyses). Conclusion The local extent of prostate cancer at MRI is associated with oncologic outcomes after prostatectomy, independent of pathologic tumor stage. This might inform a strategy on how to integrate MRI into a clinical staging algorithm. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gottlieb in this issue.

PTEN and DNA Ploidy Status by Machine Learning in Prostate Cancer

Simple Summary

Molecular tissue-based prognostic biomarkers are anticipated to complement the current risk stratification systems in prostate cancer, but their manual assessment is subjective and time-consuming. Objective assessment of such biomarkers by machine learning-based methods could advance their adoption in a clinical workflow. PTEN and DNA ploidy status are well-studied biomarkers, which can provide clinically relevant information in prostate cancer at a low cost. Using a cohort of 253 patients who received radical prostatectomy, we developed a novel, fully-automated PTEN scoring in immunohistochemically-stained tissue slides, which could be used to assess PTEN status in a reliable and reproducible manner. In an independent validation cohort of 259 patients, automatically assessed PTEN status was significantly associated with time to biochemical recurrence after radical prostatectomy, and the combination of PTEN and DNA ploidy status further improved risk stratification. These results demonstrate the utility of machine learning in biomarker assessment.

Abstract

Machine learning (ML) is expected to improve biomarker assessment. Using convolution neural networks, we developed a fully-automated method for assessing PTEN protein status in immunohistochemically-stained slides using a radical prostatectomy (RP) cohort (n = 253). It was validated according to a predefined protocol in an independent RP cohort (n = 259), alone and by measuring its prognostic value in combination with DNA ploidy status determined by ML-based image cytometry. In the primary analysis, automatically assessed dichotomized PTEN status was associated with time to biochemical recurrence (TTBCR) (hazard ratio (HR) = 3.32, 95% CI 2.05 to 5.38). Patients with both non-diploid tumors and PTEN-low had an HR of 4.63 (95% CI 2.50 to 8.57), while patients with one of these characteristics had an HR of 1.94 (95% CI 1.15 to 3.30), compared to patients with diploid tumors and PTEN-high, in univariable analysis of TTBCR in the validation cohort. Automatic PTEN scoring was strongly predictive of the PTEN status assessed by human experts (area under the curve 0.987 (95% CI 0.968 to 0.994)). This suggests that PTEN status can be accurately assessed using ML, and that the combined marker of automatically assessed PTEN and DNA ploidy status may provide an objective supplement to the existing risk stratification factors in prostate cancer.

International Multi-Site Initiative to Develop an MRI-Inclusive Nomogram for Side-Specific Prediction of Extraprostatic Extension of Prostate Cancer

BACKGROUND

To develop an international, multi-site nomogram for side-specific prediction of extraprostatic extension (EPE) of prostate cancer based on clinical, biopsy, and magnetic resonance imaging- (MRI) derived data.

METHODS

Ten institutions from the USA and Europe contributed clinical and side-specific biopsy and MRI variables of consecutive patients who underwent prostatectomy. A logistic regression model was used to develop a nomogram for predicting side-specific EPE on prostatectomy specimens. The performance of the statistical model was evaluated by bootstrap resampling and cross validation and compared with the performance of benchmark models that do not incorporate MRI findings.

RESULTS

Data from 840 patients were analyzed; pathologic EPE was found in 320/840 (31.8%). The nomogram model included patient age, prostate-specific antigen density, side-specific biopsy data (i.e., Gleason grade group, percent positive cores, tumor extent), and side-specific MRI features (i.e., presence of a PI-RADSv2 4 or 5 lesion, level of suspicion for EPE, length of capsular contact). The area under the receiver operating characteristic curve of the new, MRI-inclusive model (0.828, 95% confidence limits: 0.805, 0.852) was significantly higher than that of any of the benchmark models (p < 0.001 for all).

CONCLUSIONS

In an international, multi-site study, we developed an MRI-inclusive nomogram for the side-specific prediction of EPE of prostate cancer that demonstrated significantly greater accuracy than clinical benchmark models.

Impact of prebiopsy magnetic resonance imaging on biopsy and radical prostatectomy grade concordance

BACKGROUND

Adoption of prostate magnetic resonance imaging (MRI) before biopsy is based on evidence demonstrating superior detection of clinically significant prostate cancer on biopsy. Whether this is due to the detection of otherwise occult higher grade cancers or preferential sampling of higher grade areas within an otherwise low-grade cancer is unknown.

METHODS

To distinguish these two possibilities, this study examined the effect of prebiopsy MRI on the rate of pathologic upgrading and downgrading at prostatectomy in Surveillance, Epidemiology, and End Results-Medicare linked data from 2010 to 2015. Logistic regression was performed to assess the effect of MRI use on the Gleason grade change between biopsy and prostatectomy.

RESULTS

Among biopsy-naive men, those who underwent prebiopsy MRI had higher odds of downgrading at prostatectomy (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.05-1.66). In contrast, the odds of upgrading were significantly lower for men who underwent prebiopsy MRI (OR, 0.78; 95% CI, 0.61-0.99). Limitations included a low overall rate of MRI-utilization prior to biopsy and an inability to distinguish between template, software-assisted and cognitive fusion biopsy.

CONCLUSIONS

Prebiopsy MRI is associated with both oversampling of higher grade areas, which results in downgrading at prostatectomy, and the detection of otherwise occult higher grade lesions, which results in less upgrading at prostatectomy.

Pre-operative cellular dissociation grading in biopsies is highly predictive of post-operative tumour stage and patient outcome in head and neck squamous cell carcinoma

BACKGROUND

Pre-operative treatment planning in head and neck squamous cell carcinoma (HNSCC) is mainly dictated by clinical staging, which has major shortcomings. Histologic grading is irrelevant due to its lack of prognostic impact. Recently, a novel grading termed Cellular Dissociation Grade (CDG) based on Tumour Budding and Cell Nest Size was shown to be highly prognostic for resected HNSCC. We aimed to probe the predictive and prognostic impact of CDG in the pre-operative biopsies of HNSCC.

METHODS

We evaluated CDG in n = 160 pre-therapeutic biopsies from patients who received standardised treatment following German guidelines, and correlated the results with pre- and post-therapeutic staging data and clinical outcome.

RESULTS

Pre-operative CDG was highly predictive of post-operative tumour stage, including the prediction of occult lymph node metastasis. Uni- and multivariate analysis revealed CDG to be an independent prognosticator of overall, disease-specific and disease-free survival (p < 0.001). Hazard ratio for disease-specific survival was 6.1 (11.1) for nG2 (nG3) compared with nG1 tumours.

CONCLUSIONS

CDG is a strong outcome predictor in the pre-treatment scenario of HNSCC and identifies patients with nodal-negative disease. CDG is a purely histology-based prognosticator in the pre-therapeutic setting that supplements clinical staging and may aide therapeutic stratification of HNSCC patients.

Concordance of Gleason grading with three-dimensional ultrasound systematic biopsy and biopsy core pre-embedding

PURPOSE

To determine the value of a three-dimensional (3D) greyscale transrectal ultrasound (TRUS)-guided prostate biopsy system and biopsy core pre-embedding method on concordance between Gleason scores of needle biopsies and radical prostatectomy (RP) specimens.

METHODS

Retrospective analysis of prostate biopsies and subsequent RP for PCa in the Jeroen Bosch Hospital, the Netherlands, from 2007 to 2016. Two cohorts were analysed: conventional 2D TRUS-guided biopsies and RP (2007-2013, n = 266) versus 3D TRUS-guided biopsies with pre-embedding (2013-2016, n = 129). The impact of 3D TRUS-guidance with pre-embedding on Gleason score (GS) concordance between biopsy and RP was evaluated using the κ-coefficient. Predictors of biopsy GS 6 upgrading were assessed using logistic regression models.

RESULTS

Gleason concordance was comparable between the two cohorts with a κ = 0.44 for the 3D cohort, compared to κ = 0.42 for the 2D cohort. 3D TRUS-guidance with pre-embedding, did not significantly affect the risk of biopsy GS 6 upgrading in univariate and multivariate analysis.

CONCLUSIONS

3D TRUS-guidance with biopsy core pre-embedding did not improve Gleason concordance. Improved detection techniques are needed for recognition of low-grade disease upgrading.

Second Opinion Expert Pathology Review in Bladder Cancer: Implications for Patient Care

Objectives. To review bladder specimens referred to our facility for secondary review to determine the frequency and degree of changes in pathological diagnoses, which could affect patient care. Methods. A retrospective review of 246 bladder specimens sent to our pathology department for second opinion pathological review was performed. All consultation specimens were reviewed by a single genitourinary (GU)-subspecialized surgical pathologist. Any changes in the pathological grade, stage, or histological tumor type were noted as well as patient demographic data. Statistical analysis was performed to determine the frequency and type of discrepancies in diagnoses and determine any associations with patient demographic parameters. Results. Secondary pathology consultation of 246 bladder specimens from 233 patients were reviewed and compared with the primary diagnosis. The diagnosis was altered in 91/246 cases (37.0%). The number of cases reviewed per patient and specimen type was not associated with a change in diagnosis ( P = .19; P = .1). Of the cases with a change in diagnosis, 8 (8.8%) changed malignancy status, 46 (50.5%) changed stage, 16 (17.6%) changed tumor type (ie, change from urothelial carcinoma to prostate adenocarcinoma), 16 (17.6%) changed histological variant subtype, and 14 (15.4%) changed grade. There was no association noted between age, gender, or race and changes in diagnosis ( P = .53; P = .41; P = .70). Conclusions. Secondary pathology review with a GU-subspecialized surgical pathologist can change the stage, grade, or histological subtype on bladder biopsy and tumor resection specimens in more than one-third of cases. Age and gender were not associated with the frequency of change in diagnosis on consultation review.

Influence of pathologist experience on positive surgical margins following radical prostatectomy

BACKGROUND

A positive surgical margin (PSM) following radical prostatectomy (RP) for prostate cancer is associated with increased risk of biochemical recurrence. We sought to examine whether the pathologist is an independent predictor of PSMs.

METHODS

We performed a retrospective review of 3,557 men who underwent RP for localized prostate cancer at our institution from 2003 to 2015. We evaluated 29 separate pathologists. Univariate and multivariable logistic regression were used to test variables previously shown to influence PSM rates.

RESULTS

Overall rate of PSM was 18.9%. Compared with patients without PSM, patients with PSM had higher body mass index (mean: 28.8 vs. 28.3), Gleason score≥7 (84% vs. 66%), extracapsular extension (51% vs. 20%), and median prostate-specific antigen (5.9 vs. 5.1ng/ml) (all P<0.05). Univariate logistic regression showed that surgeon experience, pathologist experience, and pathologist genitourinary fellowship training were all predictors of PSMs (all P<0.05). Multivariable regression analysis confirmed that decreased surgeon experience, increased pathologist experience, higher pathologic Gleason score, higher pathologic stage, and higher prostate-specific antigen were significant predictors of PSMs. Increasing surgeon experience was associated with decreased odds of PSM (odds ratio = 0.79 per 1 standard deviation increase, 95% CI [0.70-0.89]). In contrast, increasing pathologist experience was associated with increased odds of PSM (odds ratio = 1.11 per 1 standard deviation increase, 95% CI [1.03-1.19]). The relationship between pathologist experience and PSM appeared to be nonlinear (Fig. 2).

CONCLUSIONS

Greater pathologist experience appears to be associated with greater odds of PSMs following radical prostatectomy, even after controlling for case mix, pathologist fellowship training, and surgeon experience. Based on these findings, pathologists with less experience reviewing RP specimens may consider requesting rereview by a dedicated genitourinary pathologist.

Results of central pathology review of prostatic biopsies in a contemporary series from a phase III, multicenter, randomized controlled trial (SHIP0804)

To investigate contemporary rates of variation in the biopsy Gleason grading in prostate cancer, between local and central pathologists, based on central review of the pathological slides from Seed and Hormone for Intermediate-risk Prostate Cancer (SHIP) 0804, a phase III, multicenter, randomized, controlled study. From April 2008 to May 2011, 18 Japanese institutions participated. All H&E slides were reviewed independently, without clinical information, and a tumor grade was assigned according to the modified Gleason grading system proposed by the International Society of Urological Pathology (ISUP). Prostate biopsy specimens of 642 cases were available for evaluation. An exact concordance rate of Gleason score (GS) between local and central pathologists was determined to be 65.3%; with the under-grading and over-grading of grades to be 14.6% and 20.1%, respectively. The central review resulted in numbers of tumor-bearing cores reassigned in 99 of 616 cases in which such information by the local pathologists was available (16.1%). Discordance in biopsy Gleason grading was still found in one third of the cases in the SHIP0804 study. This information is valuable in extrapolating the diagnostic error range in contemporary clinical studies conducted without central pathological review.

[Documentation quality of histopathology reports of prostate needle biopsies: a snapshot]

BACKGROUND

A standardized assessment of findings from prostate needle biopsies in pathology is of great importance for the individual recommendations for therapy of patients with prostate cancer. To this end criteria were developed which are formulated as recommendations in the S3 guidelines for prostate cancer and in joint instructions of the Bundesverband Deutscher Pathologen (BDP, "National Association of German Pathologists") and the Deutsche Gesellschaft für Pathologie (DGP, "German Society of Pathology"). In this article the findings from tumor positive prostate needle biopsies taken from various institutes in Germany, were investigated exclusively to determine to what extent the recommended parameters were followed.

MATERIAL AND METHODS

The study encompassed the findings from 91 patients with a mean age of 65.3 years from whom an average of 9.3 biopsy samples from different regions of the prostate were submitted. All diagnosed tumors corresponded to a standard type adenocarcinoma according to the classification of the World Health Organization (WHO) which was detected in an average of 2.5 biopsy regions per patient. The assessment was made from H & E stained serial sections which was supplemented in 11 (12.1%) cases by special staining methods and in 40 (44%) cases by immunohistochemical staining techniques. The length of the needle biopsy was documented in 88 (96.7%) cases and the tumor spread also in 88 cases. The tumor stage was reported in 16 cases (17.6%).

RESULTS

The Gleason grading score (GS) was reported in all 91 cases whereby the old GS was explicitly used in 1 case and the modified GS in all other cases. The allocated GS ranged from 4 to 10 whereby 8 cases were graded as ≤5, 46 as GS grade 6, 27 as GS grade 7 and 10 as GS >7. Out of 45 cases with several positive biopsy samples, 38 were uniformly graded (84.4%), 6 out of the 7 samples which were not uniformly graded were allocated a GS of 6 or 7 and 1 sample was graded as GS 6-9. In 64 cases (70.3%) the conventional 3-stage WHO grading (n=42) and the Helpap grading (n=22) were additionally used. The WHO and Helpap grading scores were found to be highly correlated with the GS grading scores and the Union for International Cancer Control (UICC) grading scores derived from it (χ²-test, p<0.001), although surprising allocations were selected in isolated cases.

CONCLUSION

In total, the only serious deficits were that in three cases (3.3%) no information was supplied on the estimated spread of the tumor in the tumor positive biopsies because this information can be decisive for therapy decisions, particularly for the selection of an active surveillance strategy. Also a relatively large number of cases were assigned a GS score ≤ 5 which is not recommended in the modified Gleason grading. Furthermore, translation of the GS into the other grading forms used revealed that the biological assessment of the GS showed clear differences between the various participating institutes. In conclusion, the findings of the pathologists as a rule incorporated all the parameters necessary for a therapy decision in accordance with the guidelines so that they can be considered comprehensive and completely valid apart from a few exceptions.

Magnetic resonance imaging-ultrasound fusion biopsy for prediction of final prostate pathology

PURPOSE

We explored the impact of magnetic resonance imaging-ultrasound fusion prostate biopsy on the prediction of final surgical pathology.

MATERIALS AND METHODS

A total of 54 consecutive men undergoing radical prostatectomy at UCLA after fusion biopsy were included in this prospective, institutional review board approved pilot study. Using magnetic resonance imaging-ultrasound fusion, tissue was obtained from a 12-point systematic grid (mapping biopsy) and from regions of interest detected by multiparametric magnetic resonance imaging (targeted biopsy). A single radiologist read all magnetic resonance imaging, and a single pathologist independently rereviewed all biopsy and whole mount pathology, blinded to prior interpretation and matched specimen. Gleason score concordance between biopsy and prostatectomy was the primary end point.

RESULTS

Mean patient age was 62 years and median prostate specific antigen was 6.2 ng/ml. Final Gleason score at prostatectomy was 6 (13%), 7 (70%) and 8-9 (17%). A tertiary pattern was detected in 17 (31%) men. Of 45 high suspicion (image grade 4-5) magnetic resonance imaging targets 32 (71%) contained prostate cancer. The per core cancer detection rate was 20% by systematic mapping biopsy and 42% by targeted biopsy. The highest Gleason pattern at prostatectomy was detected by systematic mapping biopsy in 54%, targeted biopsy in 54% and a combination in 81% of cases. Overall 17% of cases were upgraded from fusion biopsy to final pathology and 1 (2%) was downgraded. The combination of targeted biopsy and systematic mapping biopsy was needed to obtain the best predictive accuracy.

CONCLUSIONS

In this pilot study magnetic resonance imaging-ultrasound fusion biopsy allowed for the prediction of final prostate pathology with greater accuracy than that reported previously using conventional methods (81% vs 40% to 65%). If confirmed, these results will have important clinical implications.

Gleason scoring at a comprehensive cancer center: what's the difference?

This study attempted to determine whether the Gleason score (GS) assigned at a comprehensive cancer center better predicts risk of biochemical failure (BF) after prostate radiotherapy compared with the GS of the referring institution (RI). Between 1994 and 2007, 1649 men received radiotherapy for prostate cancer at Fox Chase Cancer Center (FCCC). The Cox proportional hazard regression was used for inferences about the relationship of time to BF and GS. Harrell's C-index (HCI) was used to assess concordance in the Cox regression between predicted and observed events. The discordance rate was 26% for any change in either major or minor Gleason pattern. In the RI GS 2 through 6 group, 79 (8%) patients were upgraded to GS 7. Twenty percent of patients with RI GS 7 were downgraded and 2% were upgraded. In the RI GS 8 through 9 group, 58% were downgraded to GS 6 (12%) or GS 7 (88%). The FCCC GS altered the NCCN risk group assignment in 144 men (9%): 92 (64%) men to lower risk and 52 (36%) to higher risk. FCCC GS was a stronger predictor of BF; the hazard ratios for GS 2 through 6 (ref), 3+4, 4+3, and 8 through 9 were 1.00 (ref), 1.82, 4.14, and 2.92, respectively. In contrast, the hazard ratios for the RI GS were 1.00 (ref), 1.53, 2.44, and 1.76, respectively. FCCC GS (HCI=0.76) had improved performance compared with RI GS (HCI=0.74). Changes in GS were common and the GS assigned by a comprehensive cancer center provided better BF risk stratification and prognostication for patients. Changes in GS may impact treatment recommendations in 9% to 26% of patients.

Interobserver variability in the pathological assessment of radical prostatectomy specimens: findings of the Laparoscopic Prostatectomy Robot Open (LAPPRO) study

OBJECTIVE

The aim of this study was to strengthen the validity of future findings in the Laparoscopic Prostatectomy Robot Open (LAPPRO) study by investigating the extent of interobserver variability between local pathologists and re-evaluating reference pathologists.

MATERIAL AND METHODS

LAPPRO is a Swedish prospective study comparing robot-assisted laparoscopic prostatectomy to open retropubic radical prostatectomy. Patients were recruited from 2008 to 2011. A random selection of 289 prostatectomy specimens was re-evaluated, in a blind fashion, by two reference pathologists from a University Hospital in Denmark and compared with original reports from local pathologists.

RESULTS

The exact concordance rate of Gleason score (GS) between local and reference pathologists was 56% (Spearman correlation coefficient 0.54). Exact concordance rates (κ value) for pathological tumour stage (pT), extraprostatic extension (EPE), surgical margin status (SMS) and seminal vesicle invasion (SVI) were 87% (0.63), 86% (0.59), 92% (0.76) and 98% (0.82), respectively. In subanalyses for surgical technique, exact concordance rates of GS, pT, EPE, SMS and SVI were 58%, 83%, 84%, 90% and 97%, respectively, for surgical technique 1 (ST1), compared to 55%, 88%, 87%, 93% and 98%, for surgical technique 2 (ST2). In ST1 specimens undergrading of GS by the local pathologists compared to central review was more common than overgrading (26% vs 16%). The inverse relationship was seen in ST2 specimens (14% vs 32%).

CONCLUSION

Re-evaluation of randomly selected prostatectomy specimens in the LAPPRO cohort showed comparable results compared to previous studies of this kind. A systematic variation in the assessment of GS exists, attributable to individual differences in judgement between pathologists. Dichotomising GS (≤ 7 vs ≥ 8) overcomes the systematic variation.

Nuclear morphometry, nucleomics and prostate cancer progression

Prostate cancer (PCa) results from a multistep process. This process includes initiation, which occurs through various aging events and multiple insults (such as chronic infection, inflammation and genetic instability through reactive oxygen species causing DNA double-strand breaks), followed by a multistep process of progression. These steps include several genetic and epigenetic alterations, as well as alterations to the chromatin structure, which occur in response to the carcinogenic stress-related events that sustain proliferative signaling. Events such as evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis are readily observed. In addition, in conjunction with these critical drivers of carcinogenesis, other factors related to the etiopathogenesis of PCa, involving energy metabolism and evasion of the immune surveillance system, appear to be involved. In addition, when cancer spread and metastasis occur, the 'tumor microenvironment' in the bone of PCa patients may provide a way to sustain dormancy or senescence and eventually establish a 'seed and soil' site where PCa proliferation and growth may occur over time. When PCa is initiated and progression ensues, significant alterations in nuclear size, shape and heterochromatin (DNA transcription) organization are found, and key nuclear transcriptional and structural proteins, as well as multiple nuclear bodies can lead to precancerous and malignant changes. These series of cellular and tissue-related malignancy-associated events can be quantified to assess disease progression and management.

Processing radical prostatectomies: an alternate-slice method is comparable with total embedding

Receipt of radical prostatectomy specimens in the histopathology laboratory is quite common in academic centers and community hospitals. Despite numerous processing protocols, there is not an accepted standard method of processing. There are potential disadvantages of total sampling of the prostate; however, other alternatives have not been proven to show significant advantages. We present a partial sampling method (alternate slice) and compare its results to the total embedding method. Consecutive radical prostatectomy specimens were selected to compare both histologic sampling methods. The primary method of sampling was total embedding. Subsequently, alternate slice sections from the anterior, middle, and posterior thirds of the gland were reviewed. Seminal vesicle, bladder neck, and margins were similarly evaluated in both methods. Total sampling resulted in an average of 30 blocks compared with 18 in the alternate slice method. Gleason correlation was 87.5%; extraprostatic extension correlation was 97.9%. There was complete correlation in margin status and perineural invasion. Pathologic staging correlation was 97.9%. In summary, this alternate slice method compares very favorably with the total embedding method.

The clinical impact of pathological review on selection the treatment modality for localized prostate cancer in candidates for brachytherapy monotherapy

AIM

To evaluate the impact of pathological review by pathologist with genitourinary expertise (PGU) on treatment modality of localized prostate cancer, we analyzed Gleason grade (GG) migration and the final treatment decision in a cohort of patients designated for permanent prostate brachytherapy (PPB).

METHODS

From February 2005 to July 2010, a total of 247 patients with localized prostate cancer diagnosed by local community hospitals were referred to our hospital for PPB monotheray. All pathologic slides of prostate biopsies were reviewed by a single PGU. Patients ultimately selected their treatment modality from our recommendations based on the review. Indication for PPB monotherapy was the NCCN classification of patients as good or intermediate risk. In addition, patient with Primary GG 4 was regarded as unadapted case.

RESULTS

Six cases were reinterpreted as no cancer (2.4%). GG change occurred in 94 cases (38.1%) of which 77 (81.9%) were upgraded and 17 (18.1%) downgraded. Of the total 247 patients, 86 (34.8%) changed therapies and 30 (12.1%) did so based on the pathologic slide review.

CONCLUSIONS

Pathological review of biopsy specimens is mandatory for the determination of treatment modality especially in candidates for monotherapy of permanent prostate brachytherapy.

Interobserver variability in histologic evaluation of radical prostatectomy between central and local pathologists: findings of TAX 3501 multinational clinical trial

OBJECTIVES

To determine the agreement between the local pathologist findings and central pathologist findings using data from the TAX 3501 trial. TAX 3501 was a randomized, multinational trial comparing the outcomes of patients with high-risk prostate cancer treated with androgen deprivation with or without docetaxel after radical prostatectomy (RP). Patient eligibility was determined by a minimal 5-year progression-free survival estimate of 60% using Kattan's nomogram.

METHODS

The pathologic findings were reassessed in 257 consecutive RP specimens by 2 central pathologists and compared with the local pathologist data.

RESULTS

For the Gleason score, agreement was found in 181 (70%) of 257 cases, upgrading in 57 (75%), and downgrading in 25% of the RP specimens The most frequent upgrade was from Gleason score 7 to 8 or 9 and downgrading from Gleason score 8 to 7. Of the upgrades and downgrades, 37% and 21% were of 2 Gleason score points, respectively. For the tumor extent, agreement was found in 179 (70%) of 256 specimens, with upstaging in 70 (91%) and downstaging in 9%. The most frequent upstage was from focal to extensive extraprostatic extension (45%). For seminal vesicle invasion, agreement was found for 238 (93%) of 256 RP specimens Almost equal rates of underdiagnosing and overdiagnosing seminal vesicle invasion was observed. For margin status, agreement was present for 229 (89%) of 256 cases. The central pathologist review led to reclassification as a positive margin in 17 cases and a negative margin in 10. For lymph node status, 2 (1%) of 210 RP specimens had positive nodes identified only by the central pathologist. Agreement was observed in 154 negative and 54 positive cases.

CONCLUSIONS

Significant interobserver variations were found between the central and local pathologists. From the central pathologist review, the progression-free survival estimates were altered in 31 patients (13%), including 22 who were reassigned a greater risk estimate, rendering them study eligible. Thus, interobserver variability affected prognostication and trial accrual.