Prostate needle biopsies

Combined Systematic and MRI-US Fusion Prostate Biopsy Has the Highest Grading Accuracy When Compared to Final Pathology

Background and objectives: Systematic prostate biopsy (SB) has a low Gleason group (GG) accuracy when compared to final pathology. This may negatively impact the inclusion of patients into specific risk groups and treatment choice. The aim of our study was to assess the GG accuracy of magnetic resonance imaging-ultrasound (MRI-US) fusion prostate biopsy. Materials and Methods: Of a cohort of minimally invasive radical prostatectomy (RP), we selected all patients who were diagnosed with prostate cancer (PCa) via MRI-US fusion biopsy (n = 115). Results: Combined biopsy had the highest rate for GG concordance (61.7% vs. 60.4% for SB vs. 45.3% for MRI-US fusion biopsy) and the lowest for upgrading (20.9% vs. 24.5% for SB vs. 34.9% for MRI-US fusion biopsy), p < 0.0001. No clinical data were predictive for upgrading or downgrading at final pathology. Locally advanced PCa was associated with a high Prostate Imaging-Reporting and Data System (PIRADS) score (p = 0.0014) and higher percentages of positive biopsy cores (PBC)/targeted (p = 0.0002) and PBC/total (p = 0.01). Positive surgical margins were correlated with higher percentages of PBC/systematic (p = 0.003) and PBC/total (p = 0.009). Conclusions: Pre-biopsy prostate MRI improves GG concordance between biopsy and RP. Combined biopsy provides the highest grading accuracy when compared to final pathology. Targeted and systematic biopsy data are predictive for adverse pathologic outcomes.

Prostate cancer reporting and staging: needle biopsy and radical prostatectomy specimens

Prostatic adenocarcinoma remains the most common cancer affecting men. A substantial majority of patients have the diagnosis made on thin needle biopsies, most often in the absence of a palpable abnormality. Treatment choices ranging from surveillance to radical prostatectomy or radiation therapy are largely driven by the pathologic findings in the biopsy specimen. The first part of this review focuses on important morphologic parameters in needle biopsy specimens that are not covered in the accompanying articles. This includes tumor quantification as well as other parameters such a extraprostatic extension, seminal vesicle invasion, perineural invasion, and lymphovascular invasion. For those men who undergo radical prostatectomy, pathologic stage and other parameters are critical in prognostication and in determining the appropriateness of adjuvant therapy. Staging parameters, including extraprostatic extension, seminal vesicle invasion, and lymph node status are discussed here. Surgical margin status is also an important parameter and definitions and reporting of this feature are detailed. Throughout the article the current reporting guidelines published by the College of American Pathologists and the International Collaboration on Cancer Reporting are highlighted.

A novel biopsy-related parameter derived from location and relationship of positive cores on standard 12-core trans-rectal ultrasound-guided prostate biopsy: a useful parameter for predicting tumor volume compared to number of positive cores

PURPOSE

To develop a novel biopsy-related parameter, named overlapping line, defined as the line between the adjacent positive cores on 12-core trans-rectal ultrasound-guided prostate biopsy, and evaluated the value of overlapping line for predicting tumor volume in the final pathologic examination.

METHODS

Among patients with prostate cancer who underwent radical prostatectomy at Boramae Medical Center, 470 patients who underwent standard 12-core trans-rectal ultrasound-guided prostate biopsy were selected for the analysis. The number of overlapping line was determined in each patient, and its effects on tumor volume were evaluated after adjusting for other variables.

RESULTS

Median prostate specific antigen level was 9.1 ng/mL, and the maximum % cancer in positive cores was 42.8%. Median numbers of positive cores and overlapping lines were three and two, respectively. The pathologic stage was T2 or less, T3a, and T3b or greater in 297 (63.5%), 104 (22.2%), and 67 patients (14.3%), respectively. Median tumor volume in prostatectomy specimen was 3.4 mL. In multivariable analysis, the number of overlapping lines (B 0.750, p < 0.001) was a significant predictor for tumor volume, in addition to prostate specific antigen level and maximum % cancer in positive cores. In addition, the model with overlapping line showed superior accuracy compared to the model with positive core based adjusted r ² (0.467 vs. 0.456).

CONCLUSIONS

The number of overlapping lines, a novel prostate biopsy-related variable, is thought to be a more reliable predictor for tumor volume compared to the number of positive cores and could be easily applied to routine daily practice.

Clonal evaluation of prostate cancer foci in biopsies with discontinuous tumor involvement by dual ERG/SPINK1 immunohistochemistry

The presence of two or more prostate cancer foci separated by intervening benign tissue in a single core is a well-recognized finding on prostate biopsy. Cancer involvement can be measured by including intervening benign tissue or only including the actual cancer involved area. Importantly, this parameter is a common enrollment criterion for active surveillance protocols. We hypothesized that spatially distinct prostate cancer foci in biopsies may arise from separate clones, impacting cancer involvement assessment. Hence, we used dual ERG/SPINK1 immunohistochemistry to determine the frequency of separate clones-when separate tumor foci showed discordant ERG and/or SPINK1 status-in discontinuously involved prostate biopsy cores from two academic institutions. In our cohort of 97 prostate biopsy cores with spatially discrete tumor foci (from 80 patients), discontinuous cancer involvement including intervening tissue ranged from 20 to 100% and Gleason scores ranged from 6 to 9. Twenty-four (25%) of 97 discontinuously involved cores harbored clonally distinct cancer foci by discordant ERG and/or SPINK1 expression status: 58% (14/24) had one ERG(+) focus, and one ERG(-)/SPINK1(-) focus; 29% (7/24) had one SPINK1(+) focus and one ERG(-)/SPINK1(-) focus; and 13% (3/24) had one ERG(+) focus and one SPINK1(+) focus. ERG and SPINK1 overexpression were mutually exclusive in all tumor foci. In summary, our results show that ~25% of discontinuously involved prostate biopsy cores showed tumor foci with discordant ERG/SPINK1 status, consistent with multiclonal disease. The relatively frequent presence of multiclonality in discontinuously involved prostate biopsy cores warrants studies on the potential clinical impact of clonality assessment, particularly in cases where tumor volume in a discontinuous core may impact active surveillance eligibility.

Does larger tumor volume explain the higher prostate specific antigen levels in black men with prostate cancer--Results from the SEARCH database

OBJECTIVES

To assess whether larger tumor volume in black men explains higher presurgical PSA levels versus white men with prostate cancer.

METHODS

We retrospectively analyzed 1904 men from the Shared Equal Access Regional Cancer Hospital database who underwent radical prostatectomy from 1990 to 2013. Geometric mean of tumor volume and preoperative PSA for each race were estimated from multivariable linear regression models.

RESULTS

There were 1104 (58%) white men and 800 (42%) black men. Black men were younger (60.2 vs. 62.9 years, p<0.001) had a higher PSA (6.7 vs. 6.0 ng/mL, p<0.001), more positive margins (47 vs. 38%, p<0.001), and seminal vesicle invasion (13 vs. 9%, p=0.007). White patients had higher clinical stage (p<0.001) and greater median tumor volume (6.0 vs. 5.3 gm, p=0.011). After multivariable adjustment (except for PSA), white men had smaller mean tumor volumes (5.2 vs. 5.8 gm, p=0.011). When further adjusted for PSA, there was no racial difference in mean tumor volume (p=0.34). After multivariable adjustment, black men had higher mean PSAs vs. white men (7.5 vs. 6.1 ng/mL, p<0.001). Results were similar after further adjusting for tumor volume: black men had 16% higher mean PSAs versus white men (7.4 vs. 6.2 ng/mL, p<0.001).

CONCLUSIONS

In this study of men undergoing radical prostatectomy at multiple equal access medical centers, racial differences in tumor volume did not explain higher presurgical PSA levels in black versus white men. The exact reason for higher PSA values in black men remains unclear.

Magnetic Resonance Imaging/Transrectal Ultrasonography Fusion Prostate Biopsy Significantly Outperforms Systematic 12-Core Biopsy for Prediction of Total Magnetic Resonance Imaging Tumor Volume in Active Surveillance Patients

OBJECTIVE

To correlate the highest percentage core involvement (HPCI) and corresponding tumor length (CTL) on systematic 12-core biopsy (SBx) and targeted magnetic resonance imaging/transrectal ultrasonography (MRI/TRUS) fusion biopsy (TBx), with total MRI prostate cancer (PCa) tumor volume (TV).

PATIENTS AND METHODS

Fifty patients meeting criteria for active surveillance (AS) based on outside SBx, who underwent 3.0T multiparametric prostate MRI (MP-MRI), followed by SBx and TBx during the same session at our institution were examined. PCa TVs were calculated using MP-MRI and then correlated using bivariate analysis with the HPCI and CTL for SBx and TBx.

RESULTS

For TBx, HPCI and CTL showed a positive correlation (R(2)=0.31, P<0.0001 and R(2)=0.37, P<0.0001, respectively) with total MRI PCa TV, whereas for SBx, these parameters showed a poor correlation (R(2)=0.00006, P=0.96 and R(2)=0.0004, P=0.89, respectively). For detection of patients with clinically significant MRI derived tumor burden greater than 500 mm(3), SBx was 25% sensitive, 90.9% specific (falsely elevated because of missed tumors and extremely low sensitivity), and 54% accurate in comparison with TBx, which was 53.6% sensitive, 86.4% specific, and 68% accurate.

CONCLUSIONS

HPCI and CTL on TBx positively correlates with total MRI PCa TV, whereas there was no correlation seen with SBx. TBx is superior to SBx for detecting tumor burden greater than 500 mm(3). When using biopsy positive MRI derived TVs, TBx better reflects overall disease burden, improving risk stratification among candidates for active surveillance.

The critical role of the pathologist in determining eligibility for active surveillance as a management option in patients with prostate cancer: consensus statement with recommendations supported by the College of American Pathologists, International Society of Urological Pathology, Association of Directors of Anatomic and Surgical Pathology, the New Zealand Society of Pathologists, and the Prostate Cancer Foundation

CONTEXT

Prostate cancer remains a significant public health problem. Recent publications of randomized trials and the US Preventive Services Task Force recommendations have drawn attention to overtreatment of localized, low-risk prostate cancer. Active surveillance, in which patients undergo regular visits with serum prostate-specific antigen tests and repeat prostate biopsies, rather than aggressive treatment with curative intent, may address overtreatment of low-risk prostate cancer. It is apparent that a greater awareness of the critical role of pathologists in determining eligibility for active surveillance is needed.

OBJECTIVES

To review the state of current knowledge about the role of active surveillance in the management of prostate cancer and to provide a multidisciplinary report focusing on pathologic parameters important to the successful identification of patients likely to succeed with active surveillance, to determine the role of molecular tests in increasing the safety of active surveillance, and to provide future directions.

DESIGN

Systematic review of literature on active surveillance for low-risk prostate cancer, pathologic parameters important for appropriate stratification, and issues regarding interobserver reproducibility. Expert panels were created to delineate the fundamental questions confronting the clinical and pathologic aspects of management of men on active surveillance.

RESULTS

Expert panelists identified pathologic parameters important for management and the related diagnostic and reporting issues. Consensus recommendations were generated where appropriate.

CONCLUSIONS

Active surveillance is an important management option for men with low-risk prostate cancer. Vital to this process is the critical role pathologic parameters have in identifying appropriate candidates for active surveillance. These findings need to be reproducible and consistently reported by surgical pathologists with accurate pathology reporting.

Predicting the risk of non-organ-confined prostate cancer when perineural invasion is found on biopsy

OBJECTIVE

To more precisely define the risk of non-organ-confined (non-OC) prostate cancer among men with perineural invasion (PNI) identified on prostate biopsy.

MATERIALS AND METHODS

The Johns Hopkins radical prostatectomy database was queried for men with PNI reported on prostate biopsy. Patients with and without non-OC disease were compared for differences in preoperative clinical and pathologic characteristics, including three biopsy-based measures of tumor volume (number of cores with cancer, percentage of cores with cancer, and maximum percent core involvement with cancer). After evaluating the different preoperative variables in univariate analyses, a multivariable logistic regression model was generated, and bootstrap estimates of the risk of non-OC disease were calculated.

RESULTS

In total, 556 patients with PNI were analyzed, 279 (50.2%) of whom were found to have non-OC prostate cancer. In univariate analyses, preoperative prostate-specific antigen, clinical T stage, biopsy Gleason sum, and the three biopsy-based measures of tumor volume were significantly associated with non-OC disease. Of the three measures of tumor volume, the best fit to the data and highest degree of model discrimination were obtained using maximum percent core involvement with cancer. Incorporating this variable, preoperative prostate-specific antigen, clinical T stage, and biopsy Gleason sum into a multivariable model, the estimated risk of non-OC disease was found to range from 13.8% to 94.4% (bootstrap corrected c-index = 0.735).

CONCLUSION

Men with PNI on prostate biopsy are at a wide range of risk for non-OC disease. Preoperative estimation of this risk is improved by considering readily available biopsy estimates of tumor volume.

Greatest percentage of involved core length and the risk of death from prostate cancer in men with highest Gleason score ≥ 7

INTRODUCTION/BACKGROUND

Men with highest GS ≥ 7 and a differing, lower GS core (ComboGS) have decreased PC-specific mortality (PCSM) risk after RT or RT and androgen deprivation therapy (ADT). Whether the greatest percentage of involved core length (GPC) modulates this risk is unknown.

PATIENTS AND METHODS

Men with GS ≥ 7 PC (n = 333) consecutively treated between December 1989 and July 2000 using RT (n = 268; 80%) or RT and 6 months of ADT (n = 65; 20%) comprised the study cohort. The GPC was calculated using biopsy core and tumor lengths. We used competing risks regression to assess whether increasing GPC was associated with increased PCSM risk in men with or without ComboGS adjusting for risk group, age, and treatment.

RESULTS

After a median follow-up of 5.36 years (interquartile range, 3.22-7.61 years), 92 (28%) men died, 28 (30%) of PC. Increasing GPC was significantly associated with increased risk of PCSM (adjusted hazard ratio, 1.02; 95% confidence interval, 1.01-1.03; P = .005). Men with GPC ≥ 50% versus < 50% had significantly greater PCSM estimates when ComboGS was present (P < .001) versus absent (P = .55). Of the 127 men with ComboGS and GPC < 50%, 83% were treated with RT alone and 2 PC deaths were observed; neither in men with GS 7 and favorable intermediate-risk PC.

CONCLUSION

Men treated with RT for ComboGS, GPC < 50%, GS 7, and favorable intermediate-risk PC have a very low risk of early PCSM. The RTOG 0815 trial will establish whether ADT is necessary to optimize curability in these men.

Differences in Upgrading of Prostate Cancer in Prostatectomies between Community and Academic Practices

Objective. To determine whether initial biopsy performed by community or academic urologists affected rates of Gleason upgrading at a tertiary referral center. Gleason upgrading from biopsy to radical prostatectomy (RP) is an important event as treatment decisions are made based on the biopsy score. Materials and Methods. We identified men undergoing RP for Gleason 3 + 3 or 3 + 4 disease at a tertiary care academic center. Biopsy performed in the community was centrally reviewed at the academic center. Multivariate logistic regression was used to determine factors associated with Gleason upgrading. Results. We reviewed 1,348 men. There was no difference in upgrading whether the biopsy was performed at academic or community sites (OR 0.9, 95% CI 0.7-1.2). Increased risk of upgrading was seen in those with >1 positive core, older men, and those with higher PSAs. Secondary pattern 4 and larger prostate size were associated with a reduction in risk of upgrading. Compared to the smallest quartile of prostate size (<35 g), those in the highest quartile (>56 g) had a 49% reduction in risk of upgrading (OR 0.51, 95% CI 0.3-0.7). Conclusion. There was no difference in upgrading between where the biopsy was performed and community and academic urologists.

Prognostic value of preoperative multiparametric magnetic resonance imaging (MRI) for predicting biochemical recurrence after radical prostatectomy

OBJECTIVE

To evaluate the suitability of preoperative multiparametric magnetic resonance imaging (MRI) positivity as a predictor of biochemical recurrence after radical prostatectomy (RP).

PATIENTS AND METHODS

We reviewed the clinical records of patients who underwent either standard RP or laparoscopic RP between January 2005 and December 2009 at our institution. Patients who received radiotherapy or androgen deprivation therapy before surgery were excluded. A total of 314 patients met the study inclusion criteria. Cox proportional hazard regression models were used for analyses. In accordance with the criteria in the established guidelines, a radiologist scored the probability of the presence of prostate cancer using a five-point scale of diagnostic confidence level. The highest confidence level of any pulse sequence was considered as the evaluation result.

RESULTS

MRI positivity was significantly associated with a high clinical stage (cT ≥ 2; P = 0.039), a high positive biopsy core rate (≥0.2; P < 0.001), a high biopsy Gleason score ([GS] ≥8; P < 0.001) and a high pathological GS (≥8; P = 0.005). Univariate analysis and multivariate analysis showed that MRI positivity was a prognostic indicator in the analysis that included only preoperative variables and also in the analysis including preoperative and pathological variables.

CONCLUSION

Multiparametric MRI positivity can independently predict biochemical recurrence after RP.

Is it possible to predict low-volume and insignificant prostate cancer by core needle biopsies?

In an attempt to minimize overtreatment of localized prostate cancer (PCa) active surveillance (AS) and minor invasive procedures have received increased attention. We investigated the accuracy of pre-operative findings in defining insignificant disease and distinguishing between unilateral/unifocal and bilateral/multifocal PCa. One-hundred and sixty patients undergoing radical prostatectomy were included. Histology reports from the biopsies and matching prostatectomies were compared. Three definitions of insignificant cancer were used: InsigE: tumour volume ≤0.5 mL; InsigW: tumour volume ≤1.3 mL; InsigM: tumour ≤5% of total prostate volume and prostate-specific antigen (PSA) ≤10 ng/mL. In all definitions, Gleason score (GS) was ≤6 and the tumour was organ confined. Biopsies alone performed poorly as a predictor of unifocal and unilateral cancer in the prostatectomy specimens with positive predictive values of 17.8% and 18.9% respectively. Inclusion of other clinical and biochemical parameters did not significantly increase the predictive value. However, the combination of GS ≤ 6, PSA ≤ 10 ng/mL and unifocal or unilateral cancer in biopsy cores resulted in a positive predictive value of 61.1%, 38.9% and 12.0%, respectively, for identifying InsigM, InsigW and InsigE in the prostate specimen. Conclusively, routine prostate biopsies cannot predict unifocal and unilateral PCa, and must be regarded insufficient to select patients for focal therapy. Although candidates for AS may be identified using standard biopsies, a considerable fraction of patients will be understaged. There is a need for more precise diagnostic tools to assess intraprostatic tumour growth.

Prognostic significance of tumor volume in radical prostatectomy and needle biopsy specimens

PURPOSE

This review addresses the controversies that persist relating to the prognosis and reporting of tumor volume in adenocarcinoma of the prostate.

MATERIALS AND METHODS

A search was performed using the MEDLINE database and referenced lists of relevant studies to obtain articles addressing the quantification of cancer on radical prostatectomy and needle biopsy.

RESULTS

In the 2010 TNM classification system T2 tumor at radical prostatectomy is subdivided into pT2a (unilateral tumor occupying less than ½ a lobe), pT2b (unilateral tumor greater than ½ a lobe) and pT2c (bilateral tumor). This pathological substaging of T2 disease fails on several accounts. In most studies pT2b disease almost does not exist. By the time a tumor is so large that it microscopically occupies more than ½ a lobe, in the majority of cases there is bilateral (pT2c) tumor. An even greater flaw of the substaging system for stage pT2 disease is the lack of prognostic significance. In reporting pathologically organ confined cancer, it should be merely noted as pT2 without further subclassification. The data are conflicting as to the independent prognostic significance of objective measurements of tumor volume in radical prostatectomy specimens. The most likely explanation for the discordant results lies in the strong correlation of tumor volume with other prognostic markers such as extraprostatic extension and positive margins. In studies where it is statistically significant on multivariate analysis, it is unlikely that knowing tumor volume improves prediction of prognosis beyond routinely reported parameters to the degree that it would be clinically useful for an individual patient. An alternative is to record tumor volume as minimal, moderate or extensive, which gives some indication to the urologist as to the extent of disease. Not only does providing an objective measurement not add useful prognostic information beyond what is otherwise routinely reported by the pathologist, but many objective measurements done in routine practice will likely not be an accurate indicator of the true tumor volume. There is also a lack of consensus regarding the best method of measuring tumor length when there are multiple foci in a single core separated by benign intervening prostatic stroma. Some pathologists, this author included, consider discontinuous foci of cancer as if it was 1 uninterrupted focus, the rationale being that these discontinuous foci are undoubtedly the same cancer going in and out of the plane of section. Measuring the cancer from where it starts to where it ends on the core gives the minimal length of cancer in the prostate. Others measure each focus individually, and the sum of these measurements is considered the cancer length on the core. Quantifying cancer with an ocular micrometer to record the total length or percent length of cancer is time-consuming, and the data are conflicting whether this is superior to other, simpler methods and whether any potential differences in predictive accuracy would translate into changes in clinical management. It is recommended that at a minimum the number of positive cores be recorded, unless fragmented involved cores preclude evaluation, along with at least 1 other more detailed measurement such as the percent of core involvement or length of cancer.

CONCLUSIONS

Consensus has been reached on some of the issues relating to quantifying tumor volume in prostate cancer, such as the lack of utility of substaging pT2 disease. Other questions such as whether to include or subtract intervening benign prostate tissue on prostate needle cores will require additional studies. Finally, matters such as the need to quantify cancer at radical prostatectomy or which method of quantifying cancer on needle biopsy is superior will likely remain contentious due to the close interrelationship and redundancy of prognostic variables.

Preoperative prediction of unifocal, unilateral, margin-negative, and small volume prostate cancer

OBJECTIVES

Contemporary prostate carcinoma is frequently of small volume and early stage. Subtotal gland ablation by minimally invasive therapies such as cryotherapy demands preoperative prediction of unifocal, unilateral, margin-negative, and small volume (less than 0.5 mL) cancer.

METHODS

We examined matched biopsy and prostatectomy and clinical data from 393 patients at two institutions who underwent surgery in 2000 through 2003. Radical prostatectomy specimens were uniformly sectioned at 5-mm intervals and completely embedded. Numerous clinical and biopsy variables were correlated by regression analysis with unifocal, unilateral, margin-negative, and 0.5 mL or less volume cancer in the prostatectomy specimen. Odds ratios (OR) were determined.

RESULTS

At prostatectomy, 92 (23%) had unifocal cancer, 90 (23%) had unilateral cancer, 348 (89%) had organ-confined cancer, and 106 (31%) had small volume cancer. Unilateral cancer occurred in 71% to 76% of cases of unilateral cancer in the biopsy (OR, 4.30; if 9 or more cores were sampled, OR rose to 6.83), and was predicted by unifocality in the biopsy (OR, 2.63). Unifocal cancer was predicted by unilateral (OR, 2.66) but not unifocal, cancer present in the biopsy. Negative surgical margins were predicted by unilateral (OR, 2.53; positive predictive value, 82%) cancer in the biopsy and by serum prostate specific antigen (OR, 5.33). Small volume cancer was predicted by unilateral (OR, 5.50) and unifocal (OR, 7.98) cancer in the biopsy; Gleason score greater than 7 predicted a non-small volume cancer (OR, 7.52).

CONCLUSIONS

Unilateral or unifocal cancer on biopsy are among the strongest predictors of unilateral, unifocal, and small volume prostate cancer in contemporary practice.

Comparison of cancers detected at only a sextant or alternative location

OBJECTIVES

To evaluate the effect of the tumour-positive biopsy site at extended biopsy on tumour volume and potential biological significance of prostate cancer.

PATIENTS AND METHODS

We retrospectively evaluated radical prostatectomy specimens from 247 consecutive men diagnosed with prostate cancer by extended biopsy. Men who had both a positive sextant and alternative site were excluded, resulting in 132 evaluable men. We assessed age, pretreatment prostate-specific antigen (PSA) level, prostate volume, pathological stage, Gleason score, total tumour volume, and location (sextant or alternative site) of the positive biopsy. Patients were grouped by location of the positive biopsy, i.e. sextant site only or alternative site only, including anterior horn, midline region and transition zone.

RESULTS

A biopsy from a sextant-only or an alternative site only was positive in 42% (56/132) and 58% (76/132) of men, respectively. There was no significant difference in PSA level, number of positive cores, pathological stage, Gleason score, total tumour volume or the incidence of low-volume/low-grade cancer (volume <0.5 mL and a Gleason score of </=6) between the groups. In men with one positive core, there was no significant difference in total tumour volume (median 0.20 vs 0.36 mL, respectively) or in the incidence of low-volume/low-grade cancer (42% vs 40%, respectively) between the groups.

CONCLUSIONS

Total tumour volume and the incidence of low-volume/low-grade cancer detected at an alternative site only were comparable to those of cancers detected at a sextant site only. Alternative site biopsy did not increase the incidence of low-volume/low-grade cancers detected.

Identification of patients with low-risk for aneuploidy: comparative discriminatory models using linear and machine-learning classifiers in prostate cancer

BACKGROUND

Prostate needle biopsy (PNB) ploidy status has proven utility to predict adverse outcomes after prostatectomy. We sought to develop models to predict ploidy status using clinicopathologic variables.

METHODS

We identified a cohort of 169 patients with a diagnosis of prostatic adenocarcinoma on PNB, and estimated ploidy status (determined using Feulgen stained biopsy tissue) using four predictors, including age, prebiopsy PSA, highest Gleason score (GS), and the percentage of involvement by carcinoma at the biopsy site with the highest GS (PCARBX). Logistic regression (LR), Neural Network (NN), and CART classifiers were constructed.

RESULTS

Univariate analyses revealed all four predictors to be significantly associated with ploidy status. On multivariable analyses, LR identified a 2-parameter model, including GS and PCARBX that had a significant ability to predict ploidy status with a 74% and 75% correct classification rate (CCR), respectively. Using the same variables, CART and NN yielded similar CCRs of 70.4%. Within GS = 6 cohort, the CART model classified over 90% of biopsies as diploid when patients had a PCARBX < 55% and a log(PSA) < 1.7.

CONCLUSIONS

Our study demonstrates that models using GS and PCARBX are able to predict PNB ploidy status with acceptable accuracy. While machine learning classifier-derived models yield similar accuracy as LR-derived models, the latter methodology has the distinct advantage of being applicable in future datasets to estimate case-specific predictions. This information may be useful in identifying potentially aneuploid patients, who can then be targeted for more aggressive therapy.

Preoperative determination of prostate cancer tumor volume: analysis through biopsy fragments

OBJECTIVE

Preoperative determination of prostate cancer (PCa) tumor volume (TV) is still a big challenge. We have assessed variables obtained in prostatic biopsy aiming at determining which is the best method to predict the TV in radical prostatectomy (RP) specimens.

MATERIALS AND METHODS

Biopsy findings of 162 men with PCa submitted to radical prostatectomy were revised. Preoperative characteristics, such as PSA, the percentage of positive fragments (PPF), the total percentage of cancer in the biopsy (TPC), the maximum percentage of cancer in a fragment (MPC), the presence of perineural invasion (PNI) and the Gleason score were correlated with postoperative surgical findings through an univariate analysis of a linear regression model.

RESULTS

The TV correlated significantly to the PPF, TPC, MPC, PSA and to the presence of PNI (p < 0.001). However, the Pearson correlation analysis test showed an R2 of only 24%, 12%, 17% and 9% for the PPF, TPC, MPC, and PSA respectively. The combination of the PPF with the PSA and the PNI analysis showed to be a better model to predict the TV (R2 of 32.3%). The TV could be determined through the formula: Volume = 1.108 + 0.203 x PSA + 0.066 x PPF + 2.193 x PNI.

CONCLUSIONS

The PPF seems to be better than the TPC and the MPC to predict the TV in the surgical specimen. Due to the weak correlation between those variables and the TV, the PSA and the presence of PNI should be used together.

Percentage of Gleason pattern 4 and 5 predicts survival after radical prostatectomy

BACKGROUND

Morphologic and clinical heterogeneity within tumor grades is well recognized in prostate cancer. The objective of the current study was to determine whether the combined percentage of Gleason patterns 4 and 5 in radical prostatectomy specimens is an independent predictor of cancer-specific survival in prostate cancer patients.

METHODS

The radical prostatectomy specimens were analyzed from 504 consecutive prostate cancer patients who were treated at Indiana University Medical Center between 1990 and 1998. Various clinical and pathologic characteristics were analyzed.

RESULTS

A higher combined percentage of Gleason patterns 4 and 5 was associated with older age, higher preoperative serum prostate-specific antigen level, higher pathologic stage, positive surgical margins, extraprostatic extension of tumor, higher Gleason score, perineural invasion, and lymph node metastasis. In the multivariate Cox regression model, the combined percentage of Gleason patterns 4 and 5 was found to be an independent predictor of cancer-specific survival (P = .04).

CONCLUSIONS

The combined percentage of Gleason patterns 4 and 5 is a powerful predictor of prostate cancer-specific survival. Assessment of high-grade cancer amounts may allow for better stratification of patients into appropriate prognostic groups and treatment protocols.

Can biopsy be a reliable predictor of spatial distribution of prostate cancer? Comparison of a novel biopsy regimen with radical prostatectomy findings

OBJECTIVES

To obtain accurate spatial information on cancer distribution with a novel prostate biopsy regimen.

METHODS

From 2003 to 2005, 265 patients underwent a three fan-shaped biopsy (3FSB) technique of 12 to 14 cores and sextant biopsy (SB) simultaneously. When both techniques had positive findings, and radical prostatectomy was performed, the concordance among the positive biopsy locations of the SB, 3FSB, and the combination of both (the reference standard biopsy [RSB]), the proven locations of cancer, and the presence of extracapsular extension and positive surgical margins was calculated.

RESULTS

A total of 41 patients were selected, and 74 locations (left and right apex, left and right lobe) had cancer. Of these, 61 were confirmed by RSB, 58 by 3FSB, and 43 by SB with a sensitivity of 95%, 78%, and 58%, respectively. The sensitivity at the apical location was consistently greater for the 3FSB at 68% (19 of 28) compared with 40% (11 of 28) for all proven apical positive localizations and 100% (19 of 19) compared with 58% (11 of 19) for the RSB. The receiver operating characteristic analysis showed 78% accuracy for 3FSB and 68% accuracy for SB compared with the RSB. At the apex, the 3FSB and SB revealed positive surgical margins with a sensitivity of 1 and 0.4, specificity of 0.067 and 0.4, positive predictive value of 0.263 and 0.182, and negative predictive value of 1 and 0.667, respectively.

CONCLUSIONS

The 3FSB had a great ability to find cancer in the gland, especially at the apex.

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

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

Comparison of Gleason grade and score between preoperative biopsy and prostatectomy specimens in prostate cancer

AIM

Although the histopathological findings obtained from biopsy specimens are important for choosing the appropriate management of prostate cancer, there have been some discrepancies in Gleason grade and consequently, score between biopsy and surgical specimens. A comparison of findings between these two kinds of specimens was performed.

METHODS

Radical prostatectomy was performed at Asahi General Hospital on 223 cases of T1b-T3 without previous cancer treatment, and the Gleason grade and score of the biopsy and surgical specimens were compared.

RESULTS

A 37% coincidence in Gleason score was obtained between biopsy and surgical specimens; coincidence including one digit difference in score was approximately 70%. Upgrading was more than downgrading. Disagreement in secondary grade was greater than that in primary grade. Disagreement in Gleason score was roughly similar among different score items and was not influenced by level of prostate-specific antigen, however, the small volume of the cancer tissues more affected the discrepancy in score.

CONCLUSION

The use of biopsy findings is required to be taken into account regarding the discrepancy.

The influence of extent of surgical margin positivity on prostate specific antigen recurrence

BACKGROUND

Positive surgical margins are an adverse prognostic factor in patients undergoing prostatectomy for prostate cancer. The extent of margin positivity varies and its influence on clinical outcome is uncertain.

AIMS

To evaluate the linear extent of margin positivity and the number and location of positive sites as prognostic indicators in a series of prostatectomy specimens evaluated with the whole mount technique.

METHODS

Eighty six consecutive margin positive prostatectomy specimens were evaluated, and all pathology data were collected prospectively. The linear extent of margin positivity was measured with an ocular micrometer and the total extent of all positive sites was summed. The total number of sites with positive margins and anatomical sites of the positive margins were analysed.

RESULTS

The linear extent of margin positivity ranged from 0.01 to 68 mm (mean, 6.8; median, 3.0) and was associated with prostate specific antigen (PSA) recurrence in univariate logistic regression (p = 0.031). In addition, the extent of margin positivity weakly correlated with preoperative PSA (p = 0.017) and tumour volume (p = 0.013), but not with age, prostate weight, Gleason score, pathological stage, or perineural invasion. The total number of positive sites was significantly higher in patients with PSA recurrence (p = 0.037). The location of the positive margin site was not associated with PSA recurrence. The extent of margin positivity correlated with PSA recurrence in univariate analysis, although it had only marginal predictive value when adjusted for Gleason score (p = 0.076).

CONCLUSIONS

The extent of margin positivity correlates with PSA recurrence in univariate analysis, although it has no predictive value independent of Gleason score.

The presence of benign prostatic glandular tissue at surgical margins does not predict PSA recurrence

BACKGROUND

Serum prostate specific antigen (PSA) increases after radical prostatectomy are thought to indicate recurrent disease, although some suggest they result from benign prostatic epithelial tissue left at surgical margins.

AIMS

To investigate whether presence, location, and extent of benign prostatic tissue at radical prostatectomy surgical margins influence patient outcome.

METHODS

One hundred and ninety nine patients with prostate cancer and negative surgical margins were studied. The prostectomy specimens were totally embedded using the whole mount technique. The apex and bladder neck, dissected as a cone from the specimen, were serially sectioned. The total length of benign prostatic tissue at the margins, measured for each location using an ocular micrometer, was obtained by summing the length of all positive sites. The presence, anatomical location, and extent of benign prostatic tissue at the margin were correlated with clinicopathological characteristics and postoperative PSA increases.

RESULTS

Fifty five cases had benign prostatic glandular tissue at the surgical margin. The mean length was 2.19 mm (0.1-14.7). The most frequent location of benign prostatic tissue was the apex (40 patients). Presence, anatomical location, and length of benign prostatic tissue at the margin were not significantly associated with age, preoperative PSA, prostate weight, pathological stage, tumour volume, largest tumour dimension, Gleason score, extraprostatic extension, seminal vesical invasion, tumour multifocality, perineural invasion, or PSA recurrence.

CONCLUSIONS

Benign prostatic tissue was frequently found in margins of apex and bladder base, but uncommon in the anterior or posterior prostate. The presence of benign prostatic tissue at surgical margins had no prognostic relevance.

The Combined Percentage of Gleason Patterns 4 and 5 Is the Best Predictor of Cancer Progression After Radical Prostatectomy

Purpose

Clinical outcome is variable in prostate cancer patients treated with radical prostatectomy. The Gleason histologic grade of prostatic adenocarcinoma is one of the strongest predictors of biologic aggressiveness of prostate cancer. We evaluated the significance of the relative proportion of high-grade cancer (Gleason patterns 4 and/or 5) in predicting cancer progression in prostate cancer patients treated with radical prostatectomy.

Patients and Methods

Radical prostatectomy specimens from 364 consecutive prostate cancer patients were totally embedded and whole mounted. Various clinical and pathologic characteristics were analyzed. All pathologic data, including Gleason grading variables, were collected prospectively.

Results

A multiple-factor analysis was performed that included the combined percentage of Gleason patterns 4 and 5, Gleason score, tumor stage, surgical margin status, preoperative prostate-specific antigen (PSA), extraprostatic extension, and total tumor volume. Using Cox regression analysis with bootstrap resampling for predictor selection, we identified the combined percentage of Gleason patterns 4 and 5 (P < .0001) and total tumor volume (P = .009) as significant predictors of PSA recurrence.

Conclusion

The combined percentage of Gleason patterns 4 and 5 is one of the most powerful predictors of patient outcome, and appears superior to conventional Gleason score in identifying patients at increased risk of disease progression. On the basis of our results, we recommend that the combined percentage of Gleason patterns 4 and 5 be evaluated in radical prostatectomy specimens. The amount of high-grade cancer in a prostatectomy specimen should be taken into account in therapeutic decision making and assessment of patient prognosis.

Preoperative prediction of Gleason grade in radical prostatectomy specimens: the influence of different Gleason grades from multiple positive biopsy sites

The Gleason score of prostate adenocarcinomas is an important preoperative predictor of cancer behavior, and is used to help guide treatment. In the setting of more than two positive biopsy sites, pathologists usually grade the tumor at each site separately, and the Gleason score may differ from each positive site. This study seeks to determine if the highest Gleason score in all biopsy sites, or the Gleason score in the site with the highest tumor volume on the needle biopsy is the best predictor of final Gleason score in the radical prostatectomy specimens. Various preoperative biopsy findings were analyzed. All 151 patients had at least two positive biopsy sites and underwent radical prostatectomy. Primary and secondary Gleason pattern grades were assigned for each positive biopsy site. The tumor volume in the needle biopsy site was defined by the percentage of areas of biopsy cores involved by cancer. The radical prostatectomy specimens were completely embedded and processed in the whole-mount method. The Gleason score from both the biopsy site with the highest Gleason score and the biopsy site with the highest tumor volume on the needle biopsy correlated equally well with final Gleason score at radical prostatectomy (Spearman correlation coefficient =0.54 for both, P<0.001). The Gleason score from both the biopsy site with the highest Gleason score and the biopsy site with the highest tumor volume on the needle biopsy also correlated with primary Gleason pattern grade at radical prostatectomy (Spearman correlation coefficient =0.53 for both, P<0.001). Secondary Gleason pattern grade from the biopsy site with the highest tumor volume on the needle biopsy correlated with secondary Gleason pattern grade at radical prostatectomy slightly better than those from the biopsy site with the highest Gleason score (Spearman correlation coefficient, 0.32 vs 0.24; both P<0.001). Our data indicate that the highest Gleason score from all sites and the Gleason score from the site with the highest tumor volume on the needle biopsy are equally and significantly predictive of final Gleason score on radical prostatectomy. Both methods of prediction are significantly predictive of primary and secondary Gleason pattern grade on radical prostatectomy. We recommend that the highest Gleason score from all positive biopsy sites should be used when assigning an initial score using needle biopsies.

Closest Distance Between Tumor and Resection Margin in Radical Prostatectomy Specimens

Complete removal of the tumor by surgery offers the best chance for cancer cure; however, many prostate cancer patients who have negative surgical margins at radical prostatectomy will still experience local and distant tumor recurrence. In other organs, the closest distance between tumor and resection margin has prognostic significance. This has not been adequately studied in prostatectomy specimens. We undertook a prospective study of 278 consecutive margin-negative whole-mount prostatectomy cases. The anatomic location and closest distance between tumor and resection margin, measured with an ocular micrometer, were analyzed. All the slides were reviewed by a single pathologist, and data were collected prospectively. The closest distance between tumor and resection margin ranged from 0.02 to 5.0 mm (mean, 0.7 mm; median, 0.5 mm) and correlated with patient age (P = 0.03), prostate weight (P = 0.002), Gleason score (P = 0.001), pathologic stage (P = 0.01), tumor volume (P < 0.001), and perineural invasion (P < 0.001). The closest distance between tumor and resection margin was not a significant predictor of PSA recurrence in univariate or multivariate logistic regression; and we do not, therefore, advocate reporting the closest distance between tumor and resection margin as a standard part of the surgical pathology report on prostatectomy specimens.