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

A second opinion pathology review improves the diagnostic concordance between prostate cancer biopsy and radical prostatectomy specimens

Objectives:

The Gleason scoring system is an essential tool for determining the treatment strategy in prostate cancer (PCa). However, the Gleason grade group (GGG) often differs between needle-core biopsy (NCB) and radical prostatectomy (RP) specimens. We investigated the diagnostic value of a second opinion pathology review using NCB specimens in PCa.

Materials and Methods:

We retrospectively evaluated 882 patients who underwent robot-assisted RP from January 2012 to September 2019. Of these, patients whose original biopsy specimens were obtained from another hospital and reviewed by the urological pathology expert at our institution were included in the study. Patients who received neoadjuvant hormonal therapy were excluded from the study. Weighted kappa (k) coefficients were used to evaluate the diagnostic accuracy of each review.

Results:

A total of 497 patients were included in this study. Substantial agreement (weighted k = 0.783) in the GGG between initial- and second-opinion diagnoses based on NCB specimens was observed in 310 cases (62.4%). Although diagnoses based on a single opinion showed moderate agreement with the GGG of RP specimens (initial: 35.2%, weighted k = 0.522; second opinion; 38.8%, weighted k = 0.560), matching initial and second opinion diagnoses improved the concordance (42.9%, 133/310 cases) to substantial agreement (weighted k = 0.626).

Conclusions:

A second opinion of PCa pathology helps to improve the diagnostic accuracy of NCB specimens. However, over half of diagnoses that matched between the initial and second opinions differed from the diagnosis of RP specimens.

Low serum total testosterone level as a predictor of upstaging and upgrading in low-risk prostate cancer patients meeting the inclusion criteria for active surveillance

Active surveillance (AS) is currently a widely accepted treatment option for men with clinically localized prostate cancer (PCa). Several reports have highlighted the association of low serum testosterone levels with high-grade, high-stage PCa. However, the impact of serum testosterone as a predictor of progression in men with low-risk PCa has been little assessed.

In this study, we evaluated the association of circulating testosterone concentrations with a staging/grading reclassification in a cohort of low-risk PCa patients meeting the inclusion criteria for the AS protocol but opting for radical prostatectomy.

Radical prostatectomy (RP) was performed in 338 patients, eligible for AS according to the following criteria: clinical stage T2a or less, PSA<10ng/ml, two or fewer cancer cores, Gleason score (GS)=6 and PSA density<0.2 ng/mL/cc. Reclassification was defined as upstaging (stage>pT2) and upgrading (GS=7; primary Gleason pattern 4) disease. Unfavorable disease was defined as the occurrence of pathological stage>pT2 and predominant Gleason score 4. Total testosterone was measured before surgery.

Low serum testosterone levels (<300 ng/dL) were significantly associated with upgrading, upstaging, unfavorable disease and positive surgical margins. The addition of testosterone to a base model, including age, PSA, PSA density, clinical stage and positive cancer involvement in cores, showed a significant independent influence of this variable on upstaging, upgrading and unfavorable disease.

In conclusion, our results support the idea that total testosterone should be a selection criterion for inclusion of low-risk PCa patients in AS programs and suggest that testosterone level less than 300 ng/dL should be considered a discouraging factor when a close AS program is considered as treatment option

Low serum testosterone predicts upgrading and upstaging of prostate cancer after radical prostatectomy

Often, pathological Gleason Score (GS) and stage of prostate cancer (PCa) were inconsistent with biopsy GS and clinical stage. However, there were no widely accepted methods predicting upgrading and upstaging PCa. In our study, we investigated the association between serum testosterone and upgrading or upstaging of PCa after radical prostatectomy (RP). We enrolled 167 patients with PCa with biopsy GS ≤6, clinical stage ≤T2c, and prostate-specific antigen (PSA) <10 ng ml⁻¹ from April 2009 to April 2015. Data including age, body mass index, preoperative PSA level, comorbidity, clinical presentation, and preoperative serum total testosterone level were collected. Upgrading occurred in 62 (37.1%) patients, and upstaging occurred in 73 (43.7%) patients. Preoperative testosterone was lower in the upgrading than nonupgrading group (3.72 vs 4.56, P< 0.01). Patients in the upstaging group had lower preoperative testosterone than those in the nonupstaging group (3.84 vs 4.57, P= 0.01). In multivariate logistic regression analysis, as both continuous and categorical variables, low serum testosterone was confirmed to be an independent predictor of pathological upgrading (P = 0.01 and P= 0.01) and upstaging (P = 0.01 and P = 0.02) after RP. We suggest that low serum testosterone (<3 ng ml⁻¹) is associated with a high rate of upgrading and upstaging after RP. It is better for surgeons to ensure close monitoring of PSA levels and imaging examination when selecting non-RP treatment, to be cautious in proceeding with nerve-sparing surgery, and to be enthusiastic in performing extended lymph node dissection when selecting RP treatment for patients with low serum testosterone.

Apparent diffusion coefficient values are superior to transrectal ultrasound-guided prostate biopsy for the assessment of prostate cancer aggressiveness

Background Few studies have focused on comparing the utility of diffusion-weighted imaging (DWI) and transrectal ultrasound (TRUS)-guided biopsy in predicting prostate cancer aggressiveness. Whether apparent diffusion coefficient (ADC) values can provide more information than TRUS-guided biopsy should be confirmed. Purpose To retrospectively assess the utility of ADC values in predicting prostate cancer aggressiveness, compared to the TRUS-guided prostate biopsy Gleason score (GS). Material and Methods The DW images of 54 patients with biopsy-proven prostate cancer were obtained using 1.5-T magnetic resonance (MR). The mean ADC values of cancerous areas and biopsy GS were correlated with prostatectomy GS and D'Amico clinical risk scores, respectively. Meanwhile, the utility of ADC values in identifying high-grade prostate cancer (with Gleason 4 and/or 5 components in prostatectomy) in patients with a biopsy GS ≤ 3 + 3 = 6 was also evaluated. Results A significant negative correlation was found between mean ADC values of cancerous areas and the prostatectomy GS ( P < 0.001) and D'Amico clinical risk scores ( P < 0.001). No significant correlation was found between biopsy GS and prostatectomy GS ( P = 0.140) and D'Amico clinical risk scores ( P = 0.342). Patients harboring Gleason 4 and/or 5 components in prostatectomy had significantly lower ADC values than those harboring no Gleason 4 and/or 5 components ( P = 0.004). Conclusion The ADC values of cancerous areas in the prostate are a better indicator than the biopsy GS in predicting prostate cancer aggressiveness. Moreover, the use of ADC values can help identify the presence of high-grade tumor in patients with a Gleason score ≤ 3 + 3 = 6 during biopsy.

T2-weighted MRI-derived textural features reflect prostate cancer aggressiveness: preliminary results

PURPOSE

To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers.

MATERIALS AND METHODS

3T multiparametric-MRI was performed on 23 prostate cancer patients prior to prostatectomy. Textural features [angular second moment (ASM), contrast, correlation, entropy], apparent diffusion coefficient (ADC), and DCE pharmacokinetic parameters (K^trans and V_e) were calculated from index tumours delineated on the T2W, DW, and DCE images, respectively. The association between the textural features and prostatectomy GS and the MRI-derived parameters, and the utility of the parameters in differentiating between GS 3+4 and 4+3 prostate cancers were assessed statistically.

RESULTS

ASM and entropy correlated significantly (p < 0.05) with both GS and median ADC. Contrast correlated moderately with median ADC. The textural features correlated insignificantly with K^trans and V_e. GS 4+3 cancers had significantly lower ASM and higher entropy than 3+4 cancers, but insignificant differences in median ADC, K^trans, and V_e. The combined texture-MRI parameters yielded higher classification accuracy (91%) than the individual parameter sets.

CONCLUSION

T2W MRI-derived textural features could serve as potential diagnostic markers, sensitive to the pathological differences in prostate cancers.

KEY POINTS

• T2W MRI-derived textural features correlate significantly with Gleason score and ADC. • T2W MRI-derived textural features differentiate Gleason score 3+4 from 4+3 cancers. • T2W image textural features could augment tumour characterization.

Extreme Gleason Upgrading From Biopsy to Radical Prostatectomy: A Population-based Analysis

OBJECTIVE

To examine the risk factors associated with the odds of extreme Gleason upgrading at radical prostatectomy (RP) (defined as a Gleason prognostic group score increase of ≥2), we utilized a large, population-based cancer registry.

MATERIALS AND METHODS

The Surveillance, Epidemiologic, and End Results database was queried (2010-2011) for all patients diagnosed with Gleason 3 + 3 or 3 + 4 on prostate needle biopsy. Available clinicopathologic factors and the odds of upgrading and extreme upgrading at RP were evaluated using multivariate logistic regression.

RESULTS

A total of 12,459 patients were identified, with a median age of 61 (interquartile range: 56-65) and a diagnostic prostate-specific antigen (PSA) of 5.5 ng/mL (interquartile range: 4.3-7.5). Upgrading was observed in 34% of men, including 44% of 7402 patients with Gleason 3 + 3 and 19% of 5057 patients with Gleason 3 + 4 disease. Age, clinical stage, diagnostic PSA, and % prostate needle biopsy cores positive were independently associated with odds of any upgrading at RP. In baseline Gleason 3 + 3 disease, extreme upgrading was observed in 6%, with increasing age, diagnostic PSA, and >50% core positivity associated with increased odds. In baseline Gleason 3 + 4 disease, extreme upgrading was observed in 4%, with diagnostic PSA and palpable disease remaining predictive. Positive surgical margins were significantly higher in patients with extreme upgrading at RP (P < .001).

CONCLUSION

Gleason upgrading at RP is common in this large population-based cohort, including extreme upgrading in a clinically significant portion.

Apparent diffusion coefficient value and ratio as noninvasive potential biomarkers to predict prostate cancer grading: comparison with prostate biopsy and radical prostatectomy specimen

OBJECTIVE. The purpose of this study is to test the association between diffusion-weighted MRI and prostate cancer Gleason score at both biopsy and final pathologic analysis after radical prostatectomy. SUBJECTS AND METHODS. Patients with prostate cancer (n = 72) underwent diffusion-weighted MRI (b values, 0, 800, and 1600 s/mm(2)) with an endorectal coil. Apparent diffusion coefficient (ADC) and ADC ratio were obtained in normal and pathologic tissue and were correlated with transrectal ultrasound-guided biopsy (n = 72) and histopathologic (n = 39) Gleason scores using the ANOVA test. ADC accuracy was estimated using ROC curves. RESULTS. Lesions suspicious for prostate cancer were detected in 65 patients. The mean ADC was 1.47 and 0.87 × 10(-3) mm(2)/s for normal and pathologic tissue, respectively (p < 0.001). When we divided the population into four groups (normal tissue and biopsy Gleason scores of 6, 7, and 8-10), then the mean ADC value was 1.47, 0.96, 0.80, and 0.78 × 10(-3) mm(2)/s, respectively (p < 0.001). The ADC ratio decreased along with an increase in biopsy Gleason score (66.9%, 56.7%, and 51.5% for Gleason scores of 6, 7 and 8-10, respectively) (ANOVA, p = 0.003) and pathologic Gleason score (ANOVA, p < 0.001). ROC curves had an AUC of 0.94 and 0.86 for ADC and ADC ratio, respectively (p = 0.012 and 0.042, respectively). CONCLUSION. Decreasing ADC values may represent a strong risk factor of harboring a poorly differentiated prostate cancer, independently of biopsy characteristics.

Urinary TMPRSS2:ERG and PCA3 in an active surveillance cohort: results from a baseline analysis in the Canary Prostate Active Surveillance Study

PURPOSE

Active surveillance is used to manage low-risk prostate cancer. Both PCA3 and TMPRSS2:ERG are promising biomarkers that may be associated with aggressive disease. This study examines the correlation of these biomarkers with higher cancer volume and grade determined at the time of biopsy in an active surveillance cohort.

EXPERIMENTAL DESIGN

Urine was collected after digital rectal examination prospectively as part of the multi-institutional Canary Prostate Active Surveillance Study (PASS). PCA3 and TMPRSS2:ERG levels were analyzed in urine collected at study entry. Biomarker scores were correlated to clinical and pathologic variables.

RESULTS

In 387 men, both PCA3 and TMPRSS2:ERG scores were significantly associated with higher volume disease. For a negative repeat biopsy, and 1% to 10%, 11% to 33%, 34% or more positive cores, median PCA3, and TMPRSS2:ERG scores increased incrementally (P < 0.005). Both PCA3 and TMPRSS2:ERG scores were also significantly associated with the presence of high-grade disease. For a negative repeat biopsy, Gleason 6 and Gleason ≥7 cancers, the median PCA3, and TMPRSS2:ERG scores also increased incrementally (P = 0.02 and P = 0.001, respectively). Using the marker scores as continuous variables, the ORs for a biopsy in which cancer was detected versus a negative repeat biopsy (ref) on modeling was 1.41 (95% CI: 1.07-1.85), P = 0.01 for PCA3 and 1.28 (95% CI: 1.10-1.49), P = 0.001 for TMPRSS2:ERG.

CONCLUSIONS

For men on active surveillance, both PCA3 and TMPRSS2:ERG seem to stratify the risk of having aggressive cancer as defined by tumor volume or Gleason score.

Role of active surveillance in the management of localized prostate cancer

Active surveillance is an increasingly recognized treatment option for men with low-risk prostate cancer. Despite encouraging evidence for oncologic efficacy and reduction in morbidity, several barriers contribute to the underuse of this management strategy. Consistent selection criteria as well as identification and validation of triggers for subsequent intervention are essential. Incorporation of novel biomarkers as well as advanced imaging techniques may improve surveillance strategies by better defining eligibility as well as improving prompt detection of disease progression.

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.

Identifying candidates for active surveillance: an evaluation of the repeat biopsy strategy for men with favorable risk prostate cancer

PURPOSE

Active surveillance is increasingly recommended to reduce overtreatment in men with favorable risk prostate cancer. A repeat confirmatory biopsy has become the standard recommendation for these men to increase the precision of this risk attribution. We investigate the usefulness of this approach by comparing the current practice standard, repeat transrectal ultrasound biopsy, with template prostate mapping.

MATERIALS AND METHODS

A total of 124 men who were attributed a favorable risk prostate cancer status based on transrectal ultrasound guided biopsy and who were considering a policy of active surveillance underwent combined transrectal ultrasound biopsy and template prostate mapping as a confirmatory strategy. Maximum Gleason grade and disease burden were compared between the 2 confirmatory tests.

RESULTS

Depending on the definition used between 8% and 22% of men had prostate cancer reclassified as clinically important by repeat transrectal ultrasound biopsy whereas template guided prostate mapping reclassified the disease in 41% to 85% of the men. Repeat transrectal ultrasound biopsy failed to detect up to 80% of clinically important cancers detected by the reference standard. The sensitivity of repeat transrectal ultrasound biopsy to identify clinically important disease varied from 9% to 24% with the negative predictive value ranging from 23% to 60%.

CONCLUSIONS

When applied to a population of men initially deemed to have favorable risk prostate cancer, transrectal ultrasound biopsy will miss a large proportion of clinically important cancers compared to template guided prostate mapping. The usefulness of repeat transrectal ultrasound biopsy in ruling out clinically important prostate cancer needs to be reconsidered.

Upgrading and downgrading of prostate cancer from biopsy to radical prostatectomy: incidence and predictive factors using the modified Gleason grading system and factoring in tertiary grades

BACKGROUND

Prior studies assessing the correlation of Gleason score (GS) at needle biopsy and corresponding radical prostatectomy (RP) predated the use of the modified Gleason scoring system and did not factor in tertiary grade patterns.

OBJECTIVE

To assess the relation of biopsy and RP grade in the largest study to date.

DESIGN, SETTING, AND PARTICIPANTS

A total of 7643 totally embedded RP and corresponding needle biopsies (2004-2010) were analyzed according to the updated Gleason system.

INTERVENTIONS

All patients underwent prostate biopsy prior to RP.

MEASUREMENTS

The relation of upgrading or downgrading to patient and cancer characteristics was compared using the chi-square test, Student t test, and multivariable logistic regression.

RESULTS AND LIMITATIONS

A total of 36.3% of cases were upgraded from a needle biopsy GS 5-6 to a higher grade at RP (11.2% with GS 6 plus tertiary). Half of the cases had matching GS 3+4=7 at biopsy and RP with an approximately equal number of cases downgraded and upgraded at RP. With biopsy GS 4+3=7, RP GS was almost equally 3+4=7 and 4+3=7. Biopsy GS 8 led to an almost equal distribution between RP GS 4+3=7, 8, and 9-10. A total of 58% of the cases had matching GS 9-10 at biopsy and RP. In multivariable analysis, increasing age (p<0.0001), increasing serum prostate-specific antigen level (p<0.0001), decreasing RP weight (p<0.0001), and increasing maximum percentage cancer/core (p<0.0001) predicted the upgrade from biopsy GS 5-6 to higher at RP. Despite factoring in multiple variables including the number of positive cores and the maximum percentage of cancer per core, the concordance indexes were not sufficiently high to justify the use of nomograms for predicting upgrading and downgrading for the individual patient.

CONCLUSIONS

Almost 20% of RP cases have tertiary patterns. A needle biopsy can sample a tertiary higher Gleason pattern in the RP, which is then not recorded in the standard GS reporting, resulting in an apparent overgrading on the needle biopsy.

Prostate MRI: diffusion-weighted imaging at 1.5T correlates better with prostatectomy Gleason Grades than TRUS-guided biopsies in peripheral zone tumours

OBJECTIVES

To investigate the usefulness of Apparent Diffusion Coefficients (ADC) in predicting prostatectomy Gleason Grades (pGG) and Scores (GS), compared with ultrasound-guided biopsy Gleason Grades (bGG).

METHODS

Twenty-four patients with biopsy-proven prostate cancer were included in the study. Diffusion-weighted images were obtained using 1.5-T MR with a pelvic phased-array coil. Median ADC values (b0,500,1000 s/mm²) were measured at the most suspicious areas in the peripheral zone. The relationship between ADC values and pGG or GS was assessed using Pearson's coefficient. The relationship between bGG and pGG or GS was also evaluated. Receiver operating characteristic (ROC) curve analysis was performed to assess the performance of each method on a qualitative level.

RESULTS

A significant negative correlation was found between mean ADCs of suspicious lesions and their pGG (r = -0.55; p < 0.01) and GS (r = -0.63; p < 0.01). No significant correlation was found between bGG and pGG (r = 0.042; p > 0.05) or GS (r = 0.048; p > 0.05). ROC analysis revealed a discriminatory performance of AUC = 0.82 for ADC and AUC = 0.46 for bGG in discerning low-grade from intermediate/high-grade lesions.

CONCLUSIONS

The ADC values of suspicious areas in the peripheral zone perform better than bGG in the correlation with prostate cancer aggressiveness, although with considerable intra-subject heterogeneity.

KEY POINTS

• Prostate cancer aggressiveness is probably underestimated and undersampled by routine ultrasound-guided biopsies. • Diffusion-weighted MR images show good linear correlation with prostate cancer aggressiveness. • DWI information may be used to improve risk-assessment in prostate cancer.

Current perspectives on Gleason grading of prostate cancer

The 5-tier Gleason grading system for prostate cancer, introduced in 1966, has been proven to be one of the main independent predictors of prostate cancer outcome. This review addresses interobserver concordance in Gleason grading; the persistence of grading discrepancies with frequent upgrading from the biopsy to the prostatectomy specimen; the 2005 International Society of Urologic Pathologists' modifications to Gleason grading; the impact of this modified grading on grade migration and outcome prediction; and molecular correlates of cancer morphology. Data from the most recent years are emphasized.