Perineural Invasion in Prostate Cancer Is More Frequently Detected by Multiparametric MRI Targeted Biopsy Compared With Standard Biopsy

Diagnosis and Pathologic Reporting of Prostate Cancer in the Era of MRI-Targeted Prostate Biopsy

Historically, the detection of prostate cancer relied upon a systematic yet random sampling of the prostate by transrectal ultrasound guided biopsy. This approach was a nontargeted technique that led to the under detection of cancers at biopsy and the upgrading of cancers at radical prostatectomy. Multiparametric MRI-targeted prostate biopsy allows for an image-directed approach to the identification of prostate cancer. MRI-targeted biopsy of the prostate is superior for the detection of clinically significant prostate cancer. As this technique has become more prevalent among urologists, pathologists need to recognize how this development impacts cancer diagnosis and reporting.

The association between perineural invasion in mpMRI-targeted and/or systematic prostate biopsy and adverse pathological outcomes in robot-assisted radical prostatectomy

INTRODUCTION AND OBJECTIVES

This study aims to investigate the relationship between perineural invasion (PNI) in targeted (TBx) and/or systematic (SBx) prostate needle biopsy and adverse pathological features of prostate cancer (PCa) in prostatectomy specimens.

MATERIALS AND METHODS

A total of 95 male patients who underwent transperineal TBx and/or concomitant SBx subsequently treated with robot-assisted radical prostatectomy for PCa between October 2015 and June 2020 were included. The performance of PNI as a classification test (sensitivity, specificity, positive and negative predictive values) and its correlation with clinically significant PCa, surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy were computed.

RESULTS

The median age of the patients was 65 (60-70) years. TBx and concomitant SBx were performed in 78 (82.1%) patients, while 16 (16.8%) patients underwent SBx alone and one (1.1%) patient underwent TBx alone. The frequency of PNI in TBx and SBx was 17 (21.5%) and 32 (34.0%), respectively. The specificity/negative predictive values of PNI for surgical margin positivity, extraprostatic extension, and seminal vesicle invasion were 79.7/88.7%, 92.5/79.0%, and 83.3/96.8%, in TBx, and 71.1/87.1%, 80.7/74.2%, and 69.5/91.9%, in SBx, respectively. There was also a statistically significant correlation between PNI in biopsy and surgical margin positivity, extraprostatic extension, and seminal vesicle invasion in prostatectomy as well as the ISUP grade group and pT stage.

CONCLUSIONS

The absence of PNI in prostate needle biopsy may predict localized PCa with a pT stage ≤ 2c and negative surgical margins in contrast to its presence which appears to be an indicator of unfavorable factors in final pathology.

Transperineal multiparametric magnetic resonance imaging-ultrasound fusion-targeted prostate biopsy combined with standard template improves perineural invasion detection

Perineural invasion (PNI) on biopsy is associated with adverse features in prostate cancer (PCa). Transrectal multiparametric magnetic resonance imaging (MRI)-targeted biopsy (TBx) has shown to detect higher presence of PNI than standard template biopsy (SBx). Transperineal biopsy provides effective cancer detection with lower complications than the transrectal approach. We compared PNI detection efficiency between SBx and TBx through transperineal approach. We identified patients with PCa who underwent transperineal TBx and concomitant standard 20-core template SBx from September 2019 to February 2021. Clinical, MRI imaging and biopsy characteristics were evaluated and compared between TBx and SBx. Two hundred thirty-eight patients with PCa underwent concomitant transperineal SBx and TBx procedures. Combined PNI+ (SBxPNI+ and/or TBxPNI+) was identified in 77 of 238 (32.4%) patients. SBx detected 23.9% PNI-positive patients and TBx detected 19.3% PNI-positive patients of all patients with PCa. Patients with PNI were with significantly different clinicopathological characteristics than patients without PNI. Although significantly more positive PCa cores and higher positive PCa core rate were found in the SBx method, patients with SBxPNI+ only shared similar features as TBxPNI+only patients. Of 176 cases with both SBxPCa and TBxPCa, TBx could detect 19 (15.1%) more PNI cases than SBx while SBx could detect 24 (18.3%) more PNI cases than TBx. Multiparametric MRI fusion-targeted biopsy in combination with template biopsy through transperineal approach achieved PNI detection rate over 30% of PCa cases. The increased PNI detection may improve the model to select active surveillance candidates in clinical practice.

MRI-targeted prostate biopsy: key considerations for pathologists

We discuss the role of the pathologist for MRI-targeted prostate biopsy with a focus on specimen processing, reporting of pathological findings and quality assurance in establishing a successful MRI-targeted biopsy programme. The authors discuss the current issues relevant to pathologists regarding MRI-targeted prostate biopsy. In addition, a brief review of the recently published literature was performed using an English literature search on PubMed with a focus on original investigations related to MRI-targeted prostate biopsy. Our search terms included the following: 'prostate cancer', 'pathology', 'histology', 'reporting', 'cores', 'imaging', 'MRI' and 'mpMRI'. Prostate multiparametric magnetic resonance imaging (mp-MRI) and MRI-targeted biopsy has been shown to improve the diagnosis of clinically significant prostatic adenocarcinoma and can affect the management of patients with prostate cancer. The current active surveillance guidelines were based on data from TRUS biopsies and not MRI-targeted biopsies. MRI-targeted biopsy acquires multiple cores of tissue from one or more suspicious lesions found on mp-MRI. The way in which multiple targeted core biopsies obtained from a single image-directed region of interest are analysed and reported can potentially alter the Gleason score and tumour burden as reported on biopsy, which could undoubtedly alter patient management. Pathologists play an important role in the reporting of MRI-targeted prostate biopsies. How we report prostate cancer grade and extent on these biopsies can influence patient management. In addition, the pathologist should be involved in the quality assurance for patients undergoing MRI-targeted prostate biopsy.

Impact of biopsy perineural invasion on the outcomes of patients who underwent radical prostatectomy: a systematic review and meta-analysis

Objectives: To investigate the association between biopsy perineural invasion (PNI) and oncological outcomes of prostate cancer (PCa) after radical prostatectomy (RP).Materials and methods: A systematic literature search was performed using PubMed, EMBASE and Web of Science up to December 2018 to identify the eligible studies that included localized PCa patients who underwent biopsy and subsequently RP as well as follow-up information. Meta-analyses were conducted using available hazard ratios (HRs) of biopsy PNI from both univariate and multivariate analyses.Results: Eighteen studies including 14,855 patients with treatment follow-up information were included in the current systematic review. The rate of biopsy PNI varied between 7.0% and 33.0%. Seven out of the 18 studies that demonstrated biopsy PNI were associated with adverse pathologic features. Thirteen out of the 18 studies showed biopsy PNI correlated significantly with higher rates of biochemical recurrence (BCR)/cancer progression status or worse prognostic outcomes. With pooled data based on four studies with available univariate analysis results and four studies with multivariate analysis, statistically significant associations were found between biopsy PNI and BCR with univariate analysis (HR = 2.05; 95% CI = 1.57-2.68; p < 0.001) and with multivariate analysis (HR = 1.57; 95% CI = 1.28-1.93; p < 0.001).Conclusion: Evidence from the included observational studies indicated that biopsy PNI was not only correlated with adverse pathologic characteristics but also with worse BCR prognosis of local PCa after RP. The status of biopsy PNI could serve as a promising risk-stratification factor to help the decision-making process, considering active surveillance (AS) or further treatment for PCa patients.

Targeted biopsy: benefits and limitations

PURPOSE OF REVIEW

To review the current literature regarding the role of multiparametric MRI and fusion-guided biopsies in urologic practice.

RECENT FINDINGS

Fusion biopsies consistently show an increase in the detection of clinically significant cancers and decrease in low-risk disease that may be more suitable for active surveillance. Although, when to incorporate multiparametric MRI into workup is not clearly agreed upon, studies have shown a clear benefit in both biopsy naïve and those with prior negative biopsies in determining the appropriate treatment strategy. More recently, cost-analysis models have been published that show that upfront MRIs are more cost-effective when considering missed cancers and treatment courses.

SUMMARY

With improved accuracy over systematic biopsies, fusion biopsies are a superior method for detection of the true grade of cancer for both biopsy naïve and patients with prior negative biopsies, choosing appropriate candidates for active surveillance, and monitoring progression on active surveillance.

Focused Submission of Tissue for Radical Prostatectomy Following Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion-Targeted Biopsy

Prostate cancer can be difficult to appreciate grossly and therefore partial sampling of the gland can lead to incorrect grading, staging, or margin status. However, submitting the entire prostate is more time consuming and costly. We investigated the use of magnetic resonance imaging/ultrasound-targeted biopsy for the selective submission of prostatectomy specimens. We performed a retrospective review for patients with cancer on targeted prostate biopsy who underwent subsequent radical prostatectomy. Prostatectomy specimens were submitted in their entirety and assessed for Grade Group, extraprostatic extension (EPE), margins, and number of blocks. For Targeted-Grossing (TG) assessment, apex margin, bladder neck margin, seminal vesicles, and vas deferens sections were included. For the remainder of the prostate, only sections from areas shown to be positive for cancer on targeted biopsy were included in the analysis. With total tissue submission, EPE was found in 39/81 (48.1%) cases and positive margins in 19/81 (23.5%) cases. The TG method required significantly fewer blocks: 15.8 ± 5.9 versus 44.9 ± 11.9 (P < .0001). The TG method would have diagnosed the correct stage in 73/81 (90.1%) cases, Grade Group in 74/81 (91.4%) cases, and margin status in 79/81 (97.5%) cases. EPE was missed completely by the TG method in 7 cases (P = .008), of which 5/7 (71.4%) had focal EPE. There was no significant difference in stage (P = .24), Grade Group (P = .95), or margin status (P = .16) between the 2 methods. Grossing utilizing selective tissue submission from areas found to be positive for prostate cancer on magnetic resonance imaging/ultrasound-targeted prostate biopsy remains inferior to complete submission of tissue for radical prostatectomy specimens.

PTEN and ERG detection in multiparametric magnetic resonance imaging/ultrasound fusion targeted prostate biopsy compared to systematic biopsy

Multiparametric magnetic resonance imaging (MRI)/ultrasound fusion targeted prostate biopsy has been shown to outperform systematic biopsy in the detection of clinically significant prostate cancer. Aside from tumor grade, tumor biomarkers such as phosphatase and tensin homolog (PTEN) and ETS-related gene (ERG) have prognostic significance in prostate cancer and may help direct management of patients with low-grade tumors. Our objective was to compare the detection of PTEN and ERG expression in MRI-targeted versus systematic prostate biopsies. We compared immunohistochemical expression for PTEN and ERG on prostate biopsy cores from patients with Grade Group (GG) 1 or GG2 prostate cancer who had undergone systematic biopsy with concurrent targeted biopsy. Fifty-three cases had both systematic and MRI-targeted prostate tissue available for staining for PTEN; and 52 cases, for ERG. ERG positivity was seen in 37/52 (71.2%) cases, and PTEN loss was seen in 15/53 (28.3%) cases. The detection of ERG expression was not significantly different between MRI-targeted and systematic biopsy (P = .4). Targeted biopsy was superior to systematic biopsy in the detection of PTEN loss (P = .02). MRI-targeted cores detected 14/15 (93.3%) cases of PTEN loss compared to 7/15 (46.7%) cases detected by systematic cores. Most cases with PTEN loss showed heterogeneous expression in both systematic and targeted cores. In 14/15 (93.3%) cases with PTEN loss, GG was the same between targeted and systematic biopsy. Targeted biopsy is superior to systematic biopsy in the detection of PTEN loss in GG1 and GG2 tumors. Inclusion of targeted cores may be helpful for evaluation of certain prognostic biomarkers.

Imaging as a Personalized Biomarker for Prostate Cancer Risk Stratification

Biomarkers provide objective data to guide clinicians in disease management. Prostate-specific antigen serves as a biomarker for screening of prostate cancer but has come under scrutiny for detection of clinically indolent disease. Multiple imaging techniques demonstrate promising results for diagnosing, staging, and determining definitive management of prostate cancer. One such modality, multiparametric magnetic resonance imaging (mpMRI), detects more clinically significant disease while missing lower volume and clinically insignificant disease. It also provides valuable information regarding tumor characteristics such as location and extraprostatic extension to guide surgical planning. Information from mpMRI may also help patients avoid unnecessary biopsies in the future. It can also be incorporated into targeted biopsies as well as following patients on active surveillance. Other novel techniques have also been developed to detect metastatic disease with advantages over traditional computer tomography and magnetic resonance imaging, which primarily rely on defined size criteria. These new techniques take advantage of underlying biological changes in prostate cancer tissue to identify metastatic disease. The purpose of this review is to present literature on imaging as a personalized biomarker for prostate cancer risk stratification.

Detection of extraprostatic disease and seminal vesicle invasion in patients undergoing magnetic resonance imaging-targeted prostate biopsies

Background

Finding incidental extraprostatic extension (EPE) or seminal vesicle invasion (SVI) by prostate cancer (PCa) is rare on standard prostate biopsy. We evaluated the clinical-pathologic features associated with EPE and SVI on multiparametric magnetic resonance imaging (MRI)/ultrasound (US) fusion-guided targeted biopsy (TB).

Methods

A retrospective review was performed from 2014-2017, selecting patients who had undergone TB. Clinical, pathologic, and radiologic features were evaluated.

Results

Five out of 333 (1.5%) patients who had PCa detected on TB had EPE and/or SVI. The average age and prostate-specific antigen (PSA) was 71 years and 17 ng/mL, respectively. The average number of cores taken on TB was 4.2. Two patients had a prior negative SB and two patients had a prior positive SB, one of which underwent radiation therapy. All patients had a PIRADSv2 suspicion score of 4 or 5. Four out of five (80%) patients underwent both SB and concurrent TB, of which 3/4 (75%) had EPE identified only on TB. One out of four (25%) patients also had both EPE and SVI, identified only on TB. One patient underwent only TB for MRI suspicion of SVI, which was pathologically confirmed on TB. On TB, one patient had Grade Group 3, two patients had Grade Group 4, and two patients had Grade Group 5 PCa. Perineural invasion (PNI) was present in 4/5 (80%) patients on TB.

Conclusions

Based on our small series, we hypothesize that MRI/US fusion TB outperforms SB in the identification of EPE and SVI. However, given the small sample size and the overall rarity of these pathologic findings on prostate biopsy, further validation is needed.

Prostate Cancers Detected by Magnetic Resonance Imaging–Targeted Biopsies Have a Higher Percentage of Gleason Pattern 4 Component and Are Less Likely to Be Upgraded in Radical Prostatectomies

Context.—

In Gleason score (GS) 7 prostate cancers, the quantity of Gleason pattern 4 (GP 4) is an important prognostic factor and influences treatment decisions. Magnetic resonance imaging (MRI)–targeted biopsy has been increasingly used in clinical practice.

Objective.—

To investigate whether MRI-targeted biopsy may detect GS 7 prostate cancer with greater GP 4 quantity, and whether it improves biopsy/radical prostatectomy GS concordance.

Design.—

A total of 243 patients with paired standard and MRI-targeted biopsies with cancer in either standard or targeted or both were studied, 65 of whom had subsequent radical prostatectomy. The biopsy findings, including GS and tumor volume, were correlated with the radical prostatectomy findings.

Results.—

More prostate cancers detected by MRI-targeted biopsy were GS 7 or higher. Mean GP 4 percentage in GS 7 cancers was 31.0% ± 29.3% by MRI-targeted biopsy versus 25.1% ± 29.5% by standard biopsy. A total of 122 of 218 (56.0%) and 96 of 217 (44.2%) prostate cancers diagnosed on targeted biopsy and standard biopsy, respectively, had a GP 4 of 10% or greater (P = .01). Gleason upgrading was seen in 12 of 59 cases (20.3%) from MRI-targeted biopsy and in 24 of 57 cases (42.1%) from standard biopsy (P = .01). Gleason upgrading correlated with the biopsy cancer volume inversely and GP 4 of 30% or less in standard biopsy. Such correlation was not found in MRI-targeted biopsy.

Conclusions.—

Magnetic resonance imaging–targeted biopsy may detect more aggressive prostate cancers and reduce the risk of Gleason upgrading in radical prostatectomy. This study supports a potential role for MRI-targeted biopsy in the workup of prostate cancer and inclusion of percentage of GP 4 in prostate biopsy reports.

Should reporting of peri-neural invasion and extra prostatic extension be mandatory in prostate cancer biopsies? correlation with outcome in biopsy cases treated conservatively

The identification of perineural invasion (PNI) and extraprostatic extension (ECE) in prostate cancer (PC) biopsies is time consuming and can be difficult. Although this is required information in many datasets, there is little evidence on their effect on outcome in patients treated conservatively. Cases of PC were identified from three cancer registries in the UK from men with clinically localized prostate cancer diagnosed by needle biopsy from 1990-2003. The endpoint was prostate cancer death (DOD). Patients treated radically within 6 months, those with objective evidence of metastases or who had prior hormone therapy were excluded. Follow-up was through cancer registries up until 2012. Deaths were divided into those from PC and those from other causes, according to WHO criteria. 988 biopsy cases (6522 biopsy cores) were centrally reviewed by three uropathologists and assigned a Gleason score and Grade Group (GG). The presence of both PNI and ECE was recorded. Of 988 patients, PNI was present in 288 (DOD = 75) and ECE in 23 (DOD = 5). On univariable analysis PNI was highly significantly associated with DOD (hazard ratio [HR] 2.28, 95% CI: 1.68, 3.1, log-rank test p-value = 4.8 × 10-8), but ECE was not (log-rank test p-value = 0.334). On multivariable analysis with GG, serum PSA (per 10%), clinical stage and extent of disease (per 10%), PNI lost significance (HR 1.16, 95% CI: 0.83, 1.63, likelihood ratio test p-value = 0.371). The utility of routinely examining prostate biopsies for ECE and PNI is doubtful as it is not independently associated with higher grade, stage or prognosis.

[Value of PI-RADS v2 scores combined with prostate specific antigen in diagnosis of peripheral zone prostate cancer: a logistic regression analysis]

OBJECTIVE

To assess the value of Prostate Imaging and Reporting and Data System: Version 2 (PI-RADS v2) combined with prostate specific antigen (PSA) in the diagnosis of peripheral zone (PZ) prostate cancer (PCa).

METHODS

The preoperative magnetic resonance imaging and PSA data were ananlyzed for 69 patients with pathologically confirmed PCa and 109 non-PCa patients. PI-RADS v2 scores (1-5) was used to evaluate the risk of PZ PCa. The total PSA (tPSA) level, free to total PSA ratio (f/t PSA), PSA density (PSAD), PZ-PSAD and PI-RADS v2 scores were compared between the PCa and non-PCa patients. Logistic regression models were established with parameters that differed significantly the two groups. The receiver opearting characteristics (ROC) curve was constructed based on the P values derived from the logical regression models and PI-RADS scores to assess the diagnostic efficiency.

RESULTS

PI-RADS v2 score, tPSA, f/t PSA, PSAD and PZ-PSAD differed significantly between the two groups (P<0.01). Four predictive multivariate models were established: Logit P=-6.825+1.024PI-RADS v2+ 0.223tPSA (A), Logit P=-4.354+1.586PI-RADS v2-12.7841f/tPSA (B), Logit P=-8.993+1.630PI-RADS v2+17.091PSAD (C), and Logit P=-9.434+1.596PI-RADS v2+10.494PZ-PSAD (D), whose area under the ROC curves was 0.908, 0.891, 0.944, and 0.961, respectively, all significantly greater than that of PI-RADS v2 score (P<0.05).

CONCLUSION

Compared with PI-RADS v2 score alone, the combination of PI-RADS v2 score and PSA in the logistic regression model can improve the diagnostic efficiency of PZ PCa and offers better confidence in the decision of biopsy in suspected cases.

DNA repair deregulation in discrete prostate cancer lesions identified on multi-parametric MRI and targeted by MRI/ultrasound fusion-guided biopsy

Prostate cancer is histologically and molecularly heterogeneous. Clinically significant disease is often driven by dominant intra-prostatic lesions (IPLs). Prostate cancers cluster into molecular phenotypes with substantial genetic heterogeneity making pathway-based molecular analysis appealing. MRI/ultrasound fusion biopsy provides a unique opportunity to characterize tumor biology of discrete lesions at diagnosis. This study determined the feasibility of pathway-based gene expression analysis of prostate biopsies and characterized cancer pathway deregulation.

Thirteen patients had prostate cancer diagnosed by MRI/ultrasound fusion biopsy and either Gleason 6 or Gleason ≥8. Gene expression profiling was performed on 14 biopsies using >700 genes representing 13 cancer pathways. Pathway-based analysis compared gene expression among samples based on clinical, pathological, and radiographic characteristics. Pathway-based gene expression analysis was successful in 12 of 14 (86%) samples. Samples clustered based upon deregulation of DNA Repair and Notch, Chromatin Modification and Cell Cycle, or all other pathways, respectively. DNA Repair demonstrated the greatest differential deregulation. Lesions with Gleason ≥8, PSA ≥10, or intense dynamic contrast enhancement (DCE) had significantly higher DNA Repair deregulation than those with Gleason 6, PSA <10, or low to moderate DCE. Alterations in DNA Repair gene expression were diverse with upregulation of markers of DNA damage and down-regulation of DNA Repair proteins. This study demonstrates the feasibility of pathway-level gene expression analysis of discrete intra-prostatic lesions sampled by MRI/ultrasound fusion biopsy. IPLs cluster into distinct molecular phenotypes, the most significantly altered being DNA Repair.

MR/US Fusion Technology: What Makes It Tick?

MR/US fusion biopsy has emerged as a significant refinement of traditional prostate cancer diagnostic techniques. Utilizing not only quantitative imaging suspicion information from mpMRI but also the spatial accuracy and three-dimensional localization allows such strategies to specifically sample areas of concern with the gland. As such, diagnostic certainty is markedly improved. In this manuscript, we aim to highlight the multidisciplinary approach (amongst urologists, radiologists, pathologists, imaging technologists, nursing staff, and patients) which is required to launch and maintain a successful prostate imaging program.

Factors predicting prostate cancer upgrading on magnetic resonance imaging-targeted biopsy in an active surveillance population

BACKGROUND

The objective of this study was to create a nomogram model integrating clinical and multiparametric magnetic resonance imaging (MP-MRI)-based variables to predict prostate cancer upgrading in a population of active surveillance (AS) patients.

METHODS

Prostate cancer patients on AS who underwent MP-MRI with magnetic resonance imaging (MRI)/ultrasound (US) fusion-guided biopsy were identified. Clinical and imaging variables, including the prostate-specific antigen density (PSAD), number of lesions, total lesion volume, total lesion density, Prostate Imaging Reporting and Data System magnetic resonance imaging suspicion score (MRI-SS), and duration between prereferral systematic and MRI/US fusion-guided biopsy sessions, were assessed. Logistic regression modeling was used to assess upgrading on MRI/US fusion-guided biopsy. A predictive model for upgrading was calculated with the significant factors identified.

RESULTS

Seventy-six patients were analyzed with a mean age of 62.5 years and a median prostate-specific antigen (PSA) level of 5.1 ng/mL. The average duration between prereferral and MRI/US biopsies was 21 months. Twenty patients (26.32%) were upgraded. The PSAD, duration between prereferral and MRI/US biopsies, MRI-SS, and MRI total lesion density were significantly associated with upgrading. A logistic regression model using these factors to predict upgrading on confirmatory MRI/US fusion biopsy had an area under the curve (AUC) of 0.84, whereas the AUC was 0.69 with PSA alone. On the basis of this model, a nomogram was generated, and using a probability cutoff of 22% as an indication of upgrading, it produced sensitivity, specificity, positive predictive, and negative predictive values of 80%, 81.25%, 57.1%, and 92.86%, respectively.

CONCLUSIONS

The integration of MRI findings with clinical parameters can add value to a model predicting upgrading from a Gleason score of 3 + 3 = 6 in men on AS. This can potentially be used as a noninvasive approach to confirm AS patients with low-risk disease for whom biopsy may be deferred. Cancer 2017;123:1941-1948. © 2017 American Cancer Society.