A study of Gleason score interpretation in different groups of UK pathologists; techniques for improving reproducibility

Expected impact of MRI-targeted biopsy interreader variability among uropathologists on ProScreen prostate cancer screening trial: a pre-trial validation study

PURPOSE

Prostate cancer (PCa) histology, particularly the Gleason score, is an independent prognostic predictor in PCa. Little is known about the inter-reader variability in grading of targeted prostate biopsy based on magnetic resonance imaging (MRI). The aim of this study was to assess inter-reader variability in Gleason grading of MRI-targeted biopsy among uropathologists and its potential impact on a population-based randomized PCa screening trial (ProScreen).

METHODS

From June 2014 to May 2018, 100 men with clinically suspected PCa were retrospectively selected. All men underwent prostate MRI and 86 underwent targeted prostate of the prostate. Six pathologists individually reviewed the pathology slides of the prostate biopsies. The five-tier ISUP (The International Society of Urological Pathology) grade grouping (GG) system was used. Fleiss' weighted kappa (κ) and Model-based kappa for associations were computed to estimate the combined agreement between individual pathologists.

RESULTS

GG reporting of targeted prostate was highly consistent among the trial pathologists. Inter-reader agreement for cancer (GG1-5) vs. benign was excellent (Model-based kappa 0.90, Fleiss' kappa κ = 0.90) and for clinically significant prostate cancer (csPCa) (GG2-5 vs. GG0 vs. GG1), it was good (Model-based kappa 0.70, Fleiss' kappa κ 0.67).

CONCLUSIONS

Inter-reader agreement in grading of MRI-targeted biopsy was good to excellent, while it was fair to moderate for MRI in the same cohort, as previously shown. Importantly, there was wide consensus by pathologists in assigning the contemporary GG on MRI-targeted biopsy suggesting high reproducibility of pathology reporting in the ProScreen trial.

Visual Assessment of 2-Dimensional Levels Within 3-Dimensional Pathology Data Sets of Prostate Needle Biopsies Reveals Substantial Spatial Heterogeneity

Prostate cancer prognostication largely relies on visual assessment of a few thinly sectioned biopsy specimens under a microscope to assign a Gleason grade group (GG). Unfortunately, the assigned GG is not always associated with a patient's outcome in part because of the limited sampling of spatially heterogeneous tumors achieved by 2-dimensional histopathology. In this study, open-top light-sheet microscopy was used to obtain 3-dimensional pathology data sets that were assessed by 4 human readers. Intrabiopsy variability was assessed by asking readers to perform Gleason grading of 5 different levels per biopsy for a total of 20 core needle biopsies (ie, 100 total images). Intrabiopsy variability (Cohen κ) was calculated as the worst pairwise agreement in GG between individual levels within each biopsy and found to be 0.34, 0.34, 0.38, and 0.43 for the 4 pathologists. These preliminary results reveal that even within a 1-mm-diameter needle core, GG based on 2-dimensional images can vary dramatically depending on the location within a biopsy being analyzed. We believe that morphologic assessment of whole biopsies in 3 dimension has the potential to enable more reliable and consistent tumor grading.

Low-risk prostate lesions: An evidence review to inform discussion on losing the "cancer" label

BACKGROUND

Active surveillance (AS) mitigates harms from overtreatment of low-risk prostate lesions. Recalibration of diagnostic thresholds to redefine which prostate lesions are considered "cancer" and/or adopting alternative diagnostic labels could increase AS uptake and continuation.

METHODS

We searched PubMed and EMBASE to October 2021 for evidence on: (1) clinical outcomes of AS, (2) subclinical prostate cancer at autopsy, (3) reproducibility of histopathological diagnosis, and (4) diagnostic drift. Evidence is presented via narrative synthesis.

RESULTS

AS: one systematic review (13 studies) of men undergoing AS found that prostate cancer-specific mortality was 0%-6% at 15 years. There was eventual termination of AS and conversion to treatment in 45%-66% of men. Four additional cohort studies reported very low rates of metastasis (0%-2.1%) and prostate cancer-specific mortality (0%-0.1%) over follow-up to 15 years. Overall, AS was terminated without medical indication in 1%-9% of men. Subclinical reservoir: 1 systematic review (29 studies) estimated that the subclinical cancer prevalence was 5% at <30 years, and increased nonlinearly to 59% by >79 years. Four additional autopsy studies (mean age: 54-72 years) reported prevalences of 12%-43%. Reproducibility: 1 recent well-conducted study found high reproducibility for low-risk prostate cancer diagnosis, but this was more variable in 7 other studies. Diagnostic drift: 4 studies provided consistent evidence of diagnostic drift, with the most recent (published 2020) reporting that 66% of cases were upgraded and 3% were downgraded when using contemporary diagnostic criteria compared to original diagnoses (1985-1995).

CONCLUSIONS

Evidence collated may inform discussion of diagnostic changes for low-risk prostate lesions.

Genome-wide identification and analysis of prognostic features in human cancers

Clinical decisions in cancer rely on precisely assessing patient risk. To improve our ability to identify the most aggressive malignancies, we constructed genome-wide survival models using gene expression, copy number, methylation, and mutation data from 10,884 patients. We identified more than 100,000 significant prognostic biomarkers and demonstrate that these genomic features can predict patient outcomes in clinically ambiguous situations. While adverse biomarkers are commonly believed to represent cancer driver genes and promising therapeutic targets, we show that cancer features associated with shorter survival times are not enriched for either oncogenes or for successful drug targets. Instead, the strongest adverse biomarkers represent widely expressed cell-cycle and housekeeping genes, and, correspondingly, nearly all therapies directed against these features have failed in clinical trials. In total, our analysis establishes a rich resource for prognostic biomarker analysis and clarifies the use of patient survival data in preclinical cancer research and therapeutic development.

Interchangeability of light and virtual microscopy for histopathological evaluation of prostate cancer

Virtual microscopy (VM) holds promise to reduce subjectivity as well as intra- and inter-observer variability for the histopathological evaluation of prostate cancer. We evaluated (i) the repeatability (intra-observer agreement) and reproducibility (inter-observer agreement) of the 2014 Gleason grading system and other selected features using standard light microscopy (LM) and an internally developed VM system, and (ii) the interchangeability of LM and VM. Two uro-pathologists reviewed 413 cores from 60 Swedish men diagnosed with non-metastatic prostate cancer 1998–2014. Reviewer 1 performed two reviews using both LM and VM. Reviewer 2 performed one review using both methods. The intra- and inter-observer agreement within and between LM and VM were assessed using Cohen’s kappa and Bland and Altman’s limits of agreement. We found good repeatability and reproducibility for both LM and VM, as well as interchangeability between LM and VM, for primary and secondary Gleason pattern, Gleason Grade Groups, poorly formed glands, cribriform pattern and comedonecrosis but not for the percentage of Gleason pattern 4. Our findings confirm the non-inferiority of VM compared to LM. The repeatability and reproducibility of percentage of Gleason pattern 4 was poor regardless of method used warranting further investigation and improvement before it is used in clinical practice.

A grading dilemma; Gleason scoring system: Are we sufficiently compatible? A multi center study

Objective

Gleason scoring is the grading system which strongly predicts the prognosis of prostate cancer. However, even being one of the most commonly used systems, the presence of different interobserver agreement rates push the uropathologists update the definitons of the Gleason patterns. In this study, we aimed to determine the interobserver agreement variability among 7 general pathologists, and one expert uropathologist from 6 different centers.

Methods

A set of 50 Hematoxylin & Eosin stained slides from 41 patients diagnosed as prostate cancer were revised by 8 different pathologists. The pathologists were also grouped according to having their residency at the same institute or working at the same center. All pathologists' and the subgroups' Gleason scores were then compared for interobserver variability by Fleiss' and Cohen's kappa tests using R v3.2.4.

Results

There were about 8 pathologists from 6 different centers revised all the slides. One of them was an expert uropathologist with experience of 18 years. Among 7 general pathologists 4 had surgical pathology experience for over 5 years whilst 3 had under 5 years. The Fleiss' kappa was found as 0.54 for primary Gleason pattern, and 0.44 for total Gleason score (moderate agreement). The Fleiss' kappa was 0.45 for grade grouping system.

Conclusion

Assigning a Gleason score for a patient can be problematic because of different interobserver agreement rates among pathologists even though the patterns were accepted as well-defined.

Histopathological re-evaluations of biopsies in prostate cancer: a nationwide observational study

BACKGROUND

Grading prostate biopsies has an important role in determining treatment strategy. Histopathological evaluations suffer from interobserver variability and therefore biopsies may be re-evaluated.

OBJECTIVE

To provide insight into the extent of, characteristics associated with and clinical implications of prostate biopsy re-evaluations in daily clinical practice.

METHODS

Patients diagnosed with prostate cancer (PCa) by biopsy between October 2015 and April 2016 identified through the Netherlands Cancer Registry were included. The proportion of re-evaluations was assessed and characteristics were compared between patients with and without biopsy re-evaluation. Interobserver concordance of ISUP grade and EAU prognostic risk classification was determined by calculating Cohen's kappa.

RESULTS

Biopsy re-evaluation was performed in 172 (3.3%) of 5214 patients. Primary reason for re-evaluation in patients treated with curative intent was referral to another hospital. Most referred patients treated with curative intent (n = 1856) had no re-evaluation (93.0%, n = 1727). Patients with biopsy re-evaluation were younger and underwent more often prostatectomy compared to patients without re-evaluation. The disagreement rate for ISUP grade was 26.1% and interobserver concordance was substantial (κ-weighted = 0.74). Re-evaluation resulted in 21.1% (n = 14) of patients with localised PCa in a different prognostic risk group. More tumours were downgraded (57.1%) than upgraded (42.9%). Interobserver concordance was very good (κ _weighted = 0.85).

CONCLUSION

Pathology review of prostate biopsies is infrequently requested by clinicians in the Netherlands but in a non-negligible minority of patients with localised PCa the pathology review led to a change in prognostic risk group which might impact their treatment.

Inter-observer variability of cribriform architecture and percent Gleason pattern 4 in prostate cancer: relation to clinical outcome

The Grade group is an important parameter for clinical decision-making in prostate cancer. Recently, percent Gleason pattern 4 and presence of invasive cribriform and/or intraductal carcinoma (CR/IDC) have been recognized for their independent predictive value for prostate cancer outcome. There is sparse data on the inter-observer agreement for these pathologic features in practice. Our objectives were to investigate inter-observer variability of percent Gleason pattern and CR/IDC and to relate individual tumour scores to clinical outcome. Our cohort included 80 consecutive radical prostatectomies with a median follow-up 87.1 months (interquartile range 43.3-119.2), of which the slide with largest tumour volume was scored by six pathologists for Grade group (four tiers: 1, 2, 3 and 4/5), percent Gleason pattern 4 (four tiers: 0-25%, 26-50%, 51-75% and 76-100%) and presence of CR/IDC (two tiers: absent, present). The individual assignments were related to post-operative biochemical recurrence (20/80). Inter-observer agreement was substantial (Krippendorff's α 0.626) for assessment of Grade group and moderate for CR/IDC (α 0.507) and percent Gleason pattern 4 (α 0.551). For each individual pathologist, biochemical recurrence rates incremented by Grade group and presence of CR/IDC, although such relation was less clear for percent Gleason pattern 4. In conclusion, inter-observer agreement for CR/IDC and percent Gleason pattern 4 is lower than for Grade groups, indicating awareness of these features needs further improvement. Grade group and CR/IDC, but not percent Gleason pattern 4 was related to biochemical recurrence for each pathologist, indicating overall validity of individual grade assignments despite inter-observer variability.

Prostatic Adenocarcinoma: A Grading from Gleason to the New Grade-Group System: A Historical and Critical Review

The introduction of the Gleason grading system revolutionised prognostic parameters and determination of patient treatment regiments for prostatic adenocarcinomas, and has become synonymous with prostate cancer, almost universally applied in clinical settings to predict radical prostatectomy specimen findings, potential biochemical failure, local recurrences, lymph nodes or distant metastases in patients not receiving any treatment as well as those receiving treatment including radiation therapy, surgical treatment such as radical prostatectomy and other therapies etc,. However, characterisation and classification of prostate cancer is very different compared to 40-50 years ago when Gleason scores were first introduced. Despite this radical shift in classification, the Gleason system has remained one of the most important prognostic factors in prostate cancer, only possible as a result of timely and appropriate modifications to this characterisation system made in 2005 and 2014. However, even after these modifications, certain limitations of the Gleason system remain, due to which a new prostate cancer prognostic grade group system was introduced in 2014, which was widely accepted in the 2014 ISUP consensus conference, and incorporated into the WHO classification of thetumor of the Urinary System and Male Genital Tract in 2016. Herein, this article will discuss how this new prognostic grade group system, which is regarded as simpler and more accurate than the Gleason system risk stratification groups, will be used in conjunction with the Gleason system to improve patient prognosis and treatment.

Multimodal Radiomic Features for the Predicting Gleason Score of Prostate Cancer

BACKGROUND

Novel radiomic features are enabling the extraction of biological data from routine sequences of MRI images. This study's purpose was to establish a new model, based on the joint intensity matrix (JIM), to predict the Gleason score (GS) of prostate cancer (PCa) patients.

METHODS

A retrospective dataset comprised of the diagnostic imaging data of 99 PCa patients was used, extracted from The Cancer Imaging Archive's (TCIA) T2-Weighted (T2-WI) and apparent diffusion coefficient (ADC) images. Radiomic features derived from JIM and the grey level co-occurrence matrix (GLCM) were extracted from the reported tumor locations. The Kruskal-Wallis test and Spearman's rank correlation identified features related to the GS. The Random Forest classifier model was implemented to identify the best performing signature of JIM and GLCM radiomic features to predict for GS.

RESULTS

Five JIM-derived features: contrast, homogeneity, difference variance, dissimilarity, and inverse difference were independent predictors of GS (p < 0.05). Combined JIM and GLCM analysis provided the best performing area-under-the-curve, with values of 78.40% for GS ≤ 6, 82.35% for GS = 3 + 4, and 64.76% for GS ≥ 4 + 3.

CONCLUSION

This retrospective study produced a novel predictive model for GS by the incorporation of JIM data from standard diagnostic MRI images.

The updated grading system of prostate carcinoma: an inter-observer agreement study among general pathologists in an academic practice

In 2016, the grading criteria for Gleason scoring (GS) have been updated in the WHO classification of tumors of the prostate, and a new set of grade groups (GG) was introduced. As the inter-observer discordance is a well-known concern in Gleason grading before the update and no reproducibility study testing the grade groups exists, we planned to evaluate the inter-observer agreement of the most updated grading system. Four pathologists assessed 126 cores of prostatic carcinoma, and Kappa (k) test was calculated. The agreements for both GS and GG were substantial (k = 0.753 and 0.752; respectively). Discerning GG 2 from 3 also attained reasonable outcome (k = 0.675). Based on our results, the updated grading system seems to be reproducible, with satisfactory inter-observer concordance rate.

Inter-observer variability of the histological classification of lupus glomerulonephritis in children

The gold standard for the classification of lupus nephritis is renal histology but reporting variation exists. The aim of this study was to assess the inter-observer variability of the 2003 International Society of Nephrology/Royal Pathology Society (ISN/RPS) lupus nephritis histological classification criteria in children. Histopathologists from a reference centre and three tertiary paediatric centres independently reviewed digitalized renal histology slides from 55 children with lupus nephritis. Histological ISN/RPS Class was assigned and features scored; lupus nephritis-activity [scored 0-24], lupus nephritis-chronicity [0-12] and tubulointerstitial activity [0-21]. In the cohort (73% females), the age at the time of biopsy was 15.5 ± 0.39 (mean ± standard error) years. Based on the reference centre, 42% (23/55) had ISN/RPS Class IV with lupus nephritis-activity score 4.23 ± 0.50, lupus nephritis-chronicity 1.81 ± 0.18 and tubulointerstitial activity 4.45 ± 0.35. There were 4-54 (mean 16.7) glomeruli per biopsy. Pathologists had fair agreement for ISN/RPS assignment (kappa; 0.26 ± 0.12), lupus nephritis-chronicity (intra-class correlation 0.36 ± 0.09) and tubulointerstitial activity (0.22 ± 0.09) scores. There was good agreement for lupus nephritis-activity scores (intra-class correlation 0.69 ± 0.06). When categorized into proliferative and non-proliferative disease, poor agreement among sites remained (kappa 0.24 ± 0.11). Despite unified criteria for the interpretation of histological features of lupus nephritis, marked reporting variation remains in clinical practice. As proliferative lupus nephritis is managed more intensively, this may influence renal outcomes.

Gleason grade 4 prostate adenocarcinoma patterns: an interobserver agreement study among genitourinary pathologists

AIMS

To assess the interobserver reproducibility of individual Gleason grade 4 growth patterns.

METHODS AND RESULTS

Twenty-three genitourinary pathologists participated in the evaluation of 60 selected high-magnification photographs. The selection included 10 cases of Gleason grade 3, 40 of Gleason grade 4 (10 per growth pattern), and 10 of Gleason grade 5. Participants were asked to select a single predominant Gleason grade per case (3, 4, or 5), and to indicate the predominant Gleason grade 4 growth pattern, if present. 'Consensus' was defined as at least 80% agreement, and 'favoured' as 60-80% agreement. Consensus on Gleason grading was reached in 47 of 60 (78%) cases, 35 of which were assigned to grade 4. In the 13 non-consensus cases, ill-formed (6/13, 46%) and fused (7/13, 54%) patterns were involved in the disagreement. Among the 20 cases where at least one pathologist assigned the ill-formed growth pattern, none (0%, 0/20) reached consensus. Consensus for fused, cribriform and glomeruloid glands was reached in 2%, 23% and 38% of cases, respectively. In nine of 35 (26%) consensus Gleason grade 4 cases, participants disagreed on the growth pattern. Six of these were characterized by large epithelial proliferations with delicate intervening fibrovascular cores, which were alternatively given the designation fused or cribriform growth pattern ('complex fused').

CONCLUSIONS

Consensus on Gleason grade 4 growth pattern was predominantly reached on cribriform and glomeruloid patterns, but rarely on ill-formed and fused glands. The complex fused glands seem to constitute a borderline pattern of unknown prognostic significance on which a consensus could not be reached.

The evolving Gleason grading system

The Gleason grading system for prostate adenocarcinoma has evolved from its original scheme established in the 1960s-1970s, to a significantly modified system after two major consensus meetings conducted by the International Society of Urologic Pathology (ISUP) in 2005 and 2014, respectively. The Gleason grading system has been incorporated into the WHO classification of prostate cancer, the AJCC/UICC staging system, and the NCCN guidelines as one of the key factors in treatment decision. Both pathologists and clinicians need to fully understand the principles and practice of this grading system. We here briefly review the historical aspects of the original scheme and the recent developments of Gleason grading system, focusing on major changes over the years that resulted in the modern Gleason grading system, which has led to a new "Grade Group" system proposed by the 2014 ISUP consensus, and adopted by the 2016 WHO classification of tumours of the prostate.

[Prostate cancer. Part 2: Review of the various tumor grading systems over the years 1966-2015 and future perspectives of the new grading of the International Society of Urological Pathology (ISUP)]

The continued development of methods in needle biopsies and radical prostatectomy for treatment of prostate cancer has given special emphasis to the question of the prognostic relevance of the various systems of grading. The classical purely histological grading system of Gleason has been modified several times in the past decades and cleared the way for a new grading system by the prognostic grading of Epstein. Assessment of the old and also modified combined histological and cytological grading of Mostofi, the World health Organization (WHO) and the urologic-pathological working group of prostate cancer in connection with the Gleason grading (combined Gleason-Helpap grading), has led to considerably improved rates of concordance between biopsy and radical prostatectomy and to improved estimations of prognosis beside its contribution to the development of a more practicable grading system for clinical use.

Gleason drift in the NIHR ProtecT study

AIMS

There is increasing evidence of Gleason score (GS) drift in prostatic core biopsies during the last two decades. The ProtecT study is a randomized controlled study and provides an excellent cohort to study the effect of time, prostate-specific antigen (PSA) level, perineural invasion, tumour length and age on GS.

METHODS AND RESULTS

The ProtecT study recruited men in the United Kingdom between 1999 and 2010. The Gleason scores were grouped into four categories ≤ 3 + 3, 3 + 4, 4 + 3 and ≥ 4 + 4 for analysis. Data from England between 2000 and 2012 were also available. A total of 3282 biopsies containing cancer were analysed. For each year of the ProtecT study, the odds of being diagnosed with a higher GS category increased by 4.9%. Higher GS was also associated with perineural invasion, increasing tumour length, age and PSA level. While biopsy GS from England was incomplete, it also showed a marked decrease in GS five and six tumours during the same period.

CONCLUSION

There was GS drift from 3 + 3 to 3 + 4 with time in the ProtecT study, but there appeared to be no significant change in percentage of GS 4 + 3 or higher. This drift was less dramatic when compared to GS in the rest of England.

[Interobserver reproducibility of Gleason grading in prostate biopsy samples]

INTRODUCTION

Gleason grading is the most common method of prostate cancer classification.

AIM

The aim of the authors was to assess the reproducibility of Gleason grading among pathologists using the same needle biopsy samples.

METHOD

23 pathologists examined 37 prostate cancer biopsies stained with hematoxylin and eosin. Gleason scores were categorised into 4 groups (2-4, 5-6, 7 and 8-10). Kappa statistics were used to reflect interobserver agreement.

RESULTS

Considering all participating pathologists, grouping into one of the 4 categories resulted in an overall kappa value of 0.49. For the individual categories, the worst agreement (kappa = 0.15) was seen with well differentiated carcinomas, and the best (kappa = 0.65) with poorly differentiated ones.

CONCLUSIONS

These results suggest that Gleason grading in biopsy samples is moderately reproducible. The kappa values vary according to the differentiation of the cancer, and there is not much difference between the results of the present study and those published in the literature. To increase reproducibility, trainings should be organised, and this could improve the quality of grading.

Gleason grading of prostate cancer in needle core biopsies: a comparison of general and urologic pathologists

BACKGROUND AND OBJECTIVES

The Gleason grading of prostate carcinoma (PCa) in needle core biopsies is a major determinant used in management planning. The objective of this study was to evaluate the concordance between general pathologists Gleason grading and that of a urologic pathologist in our community.

DESIGN AND SETTING

Retrospective review conducted at three tertiary care hospitals in Jeddah and Riyadh for all prostatic biopsies with carcinoma from January 2002 to January 2011.

METHODS

Gleason scores assigned by the original pathologist were compared with that of the reviewing urologic pathologists. Biopsies were originally obtained and diagnosed at different referring hospitals and independent laboratories. The kappa test was used to evaluate agreement between the original and review scores.

RESULTS

For 212 biopsies the exact concordance of the Gleason score assigned by the original pathologist and the reviewer was 38.7% (82/212). However, when grouped into the main four-score categories of 2-4, 5-6, 7, and 8 or greater, disagreement was noted in 88 (41.5%) biopsies; 87 were upgraded and 1 was downgraded on review. When grouped into two-score categories of low grade (≤6) and high grade (≥7), disagreement was noted in 32 (15%) of the biopsies.

CONCLUSION

Gleason grade score shows that there was only slight to fair agreement between outside and review scoring (kappa=0.43). When using only low versus high grade categorization, there was good agreement (kappa=0.69). Almost all of the cases with score disagreement were upgraded on review.

Frequency and determinants of disagreement and error in gleason scores: a population-based study of prostate cancer

BACKGROUND

To examine factors that affect accuracy and reliability of prostate cancer grade we compared Gleason scores documented in pathology reports and those assigned by urologic pathologists in a population-based study.

METHODS

A stratified random sample of 318 prostate cancer cases was selected to ensure representation of whites and African-Americans and to include facilities of various types. The slides borrowed from reporting facilities were scanned and the resulting digital images were re-reviewed by two urologic pathologists. If the two urologic pathologists disagreed, a third urologic pathologist was asked to help arrive at a final "gold standard" result. The agreements between reviewers and between the pathology reports and the "gold standard" were examined by calculating kappa statistics. The determinants of discordance in Gleason scores were evaluated using multivariate models with results expressed as odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The kappa values (95% CI) reflecting agreement between the pathology reports and the "gold standard," were 0.61 (95% CI: 0.54, 0.68) for biopsies, and 0.37 (0.23, 0.51) for prostatectomies. Sixty three percent of discordant biopsies and 72% of discordant prostatectomies showed only minimal differences. Using freestanding laboratories as reference, the likelihood of discordance between pathology reports and expert-assigned biopsy Gleason scores was particularly elevated for small community hospitals (OR = 2.98; 95% CI: 1.73, 5.14).

CONCLUSIONS

The level of agreement between pathology reports and expert review depends on the type of diagnosing facility, but may also depend on the level of expertise and specialization of individual pathologists.

Reducing interrater variability and improving health care: a meta-analytical review

OBJECTIVES

In the scientific literature about reliability, the main approach to increasing reliability seems to involve increasing the number of observers and improving the instrument used. Other aspects for improving reliability - like the training of raters - seem to receive less notice. It is worth asking whether this technical approach could be complemented by training the user of the instrument. A systematic meta-analytical review of the research literature was performed to answer this question and examine the effectiveness of planned interventions for improving interrater reliability of health care professionals.

METHOD

The databases of PubMed (MEDLINE), Embase, Omega and PsycINFO were searched. The inclusion criteria were met by 57 studies. Details extracted from the studies included the study design, the number of observers and the number of observed cases, the intervention, the type of instrument (whether or not it was highly technical), and statistical information about the agreement before and after the intervention. Interventions were categorized into three groups: training of professionals, improving the diagnostic instrument and a combination of training and improving the instrument. A meta-analysis was performed by means of linear regression.

RESULTS

The interventions were arranged according to their effectiveness in improving the diagnostic instrument (mean change: β = 0.13), training combined with improving the instrument (mean change: β = 0.10) and training (mean change: β = 0.09).

CONCLUSION

On average, although all types of interventions are effective, improving the diagnostic instrument seems to be the most effective. Especially when highly technical instruments were concerned, improvement proved to be very effective (β = 0.52). Because instrumental variables constitute a major source of error, improving the instrument is an important approach. However, this review offers solid arguments that can complement the literature and practice, with a focus on training the user of the instrument.

Implications of the International Society of Urological Pathology modified Gleason grading system

CONTEXT

Histologic grading is the clinically most useful tissue-based predictor of prognosis for prostate cancer. Over the years, there has been a gradual shift in how the Gleason grading is applied in practice, with a general trend toward upgrading. A consensus conference was organized in 2005 by the International Society of Urological Pathology (ISUP) for standardizing both the perception of histologic patterns and how the grade information is compiled and reported.

OBJECTIVE

To review the implications of the ISUP modified Gleason grading system.

DATA SOURCES

Personal experience and review of the current literature.

CONCLUSIONS

The recommendations regarding pattern interpretation and reporting are summarized. The practical consequences of the ISUP modification of the Gleason grading are reported. The prognostic importance of the Gleason score, its reproducibility, and its preoperative assessment are discussed. Subsequent proposals for slight modifications to the ISUP grading system are described.

Prostate gland biopsies and prostatectomies: an Ontario community hospital experience

OBJECTIVE

Transrectal ultrasound-guided core biopsies of the prostate gland and prostatectomies have become common procedures at many community hospitals in Canada, especially in the era of serum prostate-specific antigen (PSA) screening for prostate cancer. The Gleason grading of prostate cancer in biopsies and prostatectomies is a major determinant used for treatment planning. There is evidence in the literature that suggests important discordance between community hospital pathologists and urological pathologists with respect to the Gleason grading of prostate cancer. Our objective was to determine the diagnostic rates and Gleason scoring patterns for prostate gland biopsies and prostatectomies at our institution compared with the literature.

METHODS

We conducted a retrospective review of all prostate gland biopsies and prostatectomies performed at the Grey Bruce Health Services from January 2005 to September 2005. We collected data from 194 biopsies and 44 prostatectomies. We obtained prebiopsy serum PSA levels and digital rectal exam results for all patients from urologists' office records.

RESULTS

The average age for men having biopsies was 65.8 (standard deviation [SD] 8.6) years, and the average prebiopsy serum PSA level was 8.7 (median 7.1, SD 6.2) mug/L. The rates of diagnosis from prostate gland biopsies of benign (17.6%), high-grade prostatic intraepithelial neoplasia (11.0%), atypical small acinar proliferation suspicious for invasive malignancy (13.2%) and invasive prostatic adenocarcinoma (58.2%) at our institution were significantly different than those reported in the literature (p < 0.001). We observed a significant variation in the rates of these diagnoses among the community hospital pathologists in our study (p = 0.004). There was a strong correlation between the increasing number of positive core biopsy sites and increasing Gleason scores in biopsies (p < 0.001). There was also a strong correlation between increasing pre-biopsy serum PSA levels and increasing Gleason scores in biopsies (p < 0.001). A substantial proportion (21.9%) of the biopsies given the Gleason score of 6 had a Gleason score of 7 in the prostatectomy specimen.

CONCLUSION

Our results showed a significant difference in prostate gland biopsy categorical diagnoses compared with the literature. There were also significant differences in categorical diagnoses of prostate gland biopsies among the community hospital pathologists in our study. The data identify a strong positive correlation between the increasing number of positive core biopsy sites and increasing Gleason scores in biopsies, as well as a strong positive correlation between increasing prebiopsy serum PSA levels and increasing Gleason scores in biopsies that revealed cancer. We would encourage other community hospital pathologists, in collaboration with their urologists, to review periodically their prostate gland pathology practices in an attempt to improve the uniformity of diagnoses.

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.

Decision support systems for morphology-based diagnosis and prognosis of prostate neoplasms: a methodological approach

Recent advances in computer and information technologies have allowed the integration of both numeric and non-numeric data, that is, descriptive, linguistic terms. This has led at 1 end of the spectrum of technology development to machine vision based on image understanding and, at the other, to decision support systems. This has had a significant impact on our capability to derive diagnostic and prognostic information from histopathological material with prostate neoplasms. Cancer 2009;115(13 suppl):3068-77. (c) 2009 American Cancer Society.

Interobserver agreement of Gleason score and modified Gleason score in needle biopsy and in surgical specimen of prostate cancer

INTRODUCTION

Gleason score, which has a high interobserver variability, is used to classify prostate cancer. The most recent consensus valued the tertiary Gleason pattern and recommended its use in the final score of needle biopsies (modified Gleason score). This pattern is considered to be of high prognostic value in surgical specimens. This study emphasized the evaluation of the modified score agreement in needle biopsies and in surgical specimen, as well as the interobserver variability of this score.

MATERIALS AND METHODS

Three pathologists evaluated the slides of needle biopsies and surgical specimens of 110 patients, reporting primary, secondary and tertiary Gleason patterns and after that, traditional and modified Gleason scores were calculated. Kappa test (K) assessed the interobserver agreement and the agreement between the traditional and modified scores of the biopsy and of the surgical specimen.

RESULTS

Interobserver agreement in the biopsy was K = 0.36 and K = 0.35, and in the surgical specimen it was K = 0.46 and K = 0.36, for the traditional and modified scores, respectively. The tertiary Gleason grade was found in 8%, 0% and 2% of the biopsies and in 8%, 0% and 13% of the surgical specimens, according to observers 1, 2 and 3, respectively. When evaluating the agreement of the traditional and modified Gleason scores in needle biopsy with both scores of the surgical specimen, a similar agreement was found through Kappa.

CONCLUSION

Contrary to what was expected, the modified Gleason score was not superior in the agreement between the biopsy score and the specimen, or in interobserver reproducibility, in this study.

[Active surveillance of localized prostate cancer. Significance of prostate core needle biopsies]

Today, more than 80% of men diagnosed with prostate cancer (PCA) by PSA screening do not die from the sequelae of their disease. About 70% present with early, organ-confined cancer and almost half of them are small (<5 cm(3)) without evidence of progression over years (insignificant PCA). It is assumed that screening brings the diagnosis of PCA forward by about 9 years and that in almost one third of these cases immediate radical prostatectomy or radiotherapy would result in overtreatment. Thus, the treatment strategy of "active surveillance" with selective but delayed intervention for patients with organ-confined PCA could be an attractive alternative to the known curative therapy options. However, a prerequisite of such a therapeutic approach would be a precise identification of patients at high risk for cancer progression. Careful work-up of prostate core needle biopsies including improved pre-embedding preparation and detailed interpretation are of the utmost importance. A Gleason score < or =6 and tumor in only one or two cores are considered predictive of organ-confined cancer. Pathologists should concentrate on correct Gleason scoring in core needle biopsies and identification of lesions that exclude a patient from active surveillance.

Should the Gleason grading system for prostate cancer be modified to account for high-grade tertiary components? A systematic review and meta-analysis

The Gleason system for grading prostate cancer assigns a score on the basis of the most prevalent and second most prevalent grade. Several studies have investigated the clinical significance of a tertiary grade in radical prostatectomy samples. A systematic search of the published work identified seven studies that reported the prognostic value of a tertiary Gleason grade. Three studies correlated the presence of a tertiary grade with pathological stage, and six with prostate-specific antigen recurrence or clinical progression. In the small number of studies available, the frequency of a tertiary grade was consistently higher in samples characterised with pathological variables of poor outcome, such as extra-prostatic extension and positive surgical margins, but not lymph-node metastases. In five studies the presence of a tertiary grade increased the risk of prostate-specific antigen recurrence after radical prostatectomy by a factor of 2.5. However, modification of the Gleason score to include a tertiary grade in Gleason 4+3 tumours might overestimate the risk of seminal-vesicle or lymph-node invasion. This systematic review has established the association of a tertiary grade with poorer outcome than that associated with no tertiary grade. A tertiary grade should, therefore, be included in the pathological reporting of prostate cancer and be considered in the interpretation and design of clinical trials. However, all studies assessed for this review were retrospective, potentially affected by selection bias, and based on radical prostatectomy samples or transurethral resections rather than biopsy samples. Therefore, more evidence is needed to warrant the adaptation of the Gleason system to account for the presence of a tertiary grade, especially when scoring prostatic biopsies and applying predictive algorithms.