Fragmentation of prostatic needle biopsy cores containing adenocarcinoma: the role of specimen submission

Cumulative cancer locations on prostate biopsy and active surveillance outcomes in the MRI era

BACKGROUND

To validate the use of a cumulative cancer locations (CCLO) score, a measurement of tumor volume on biopsy, and to develop a novel magnetic resonance imaging (MRI)-informed CCLO (mCCLO) score to predict clinical outcomes on active surveillance (AS).

METHODS

The CCLO score is a sum of uniquely involved sextants with prostate cancer on diagnostic + confirmatory biopsy. The mCCLO score incorporates MRI findings into the CCLO score. Participants included 1284 individuals enrolled on AS between 1994 and 2022, 343 of whom underwent prostate MRI. The primary outcome was grade reclassification (GR) to grade group ≥2 disease; the secondary outcome was receipt of definitive treatment.

RESULTS

Increasing CCLO and mCCLO risk groups were associated with higher risk of GR and undergoing definitive treatment (both p < 0.001). On multivariable analysis, increasing mCCLO score was associated with higher risk of GR and receipt of definitive treatment (hazard ratios [HRs] per 1-unit increase: 1.26 [95% confidence interval [CI]: 1.12-1.41] and 1.21 [95% CI: 1.07-1.36], respectively). The model using mCCLO score to predict GR (c-index: 0.671; 95% CI: 0.621-0.721) performed at least as well as models using the number of cores positive for cancer (0.664 [0.613-0.715]; p = 0.7) and the maximum percentage of cancer in a core (0.641 [0.585-0.696]; p = 0.14).

CONCLUSIONS

The CCLO score is a valid, objective metric to predict GR and receipt of treatment in a large AS cohort. The ability of the MRI-informed mCCLO to predict GR is on par with traditional metrics of tumor volume but is more descriptive and may benefit from greater reproducibility. The mCCLO score can be implemented as a shorthand, informative tool for counseling patients about whether to remain on AS.

Prostate biopsy quality and patient experience with the novel Forsvall biopsy needle - a randomized controlled non-inferiority trial

BACKGROUND

Transrectal prostate biopsy (TRbx) carries an increasing risk of infection. The Forsvall Needle Prototype (FNP) is a novel biopsy needle that reduces bacterial load brought across the rectum and may therefore reduce infection risk. The objective of this study was to compare biopsy length, quality and patient experience for the FNP Version 2 (FNP2) versus a standard Tru-Cut needle.

METHODS

We conducted a randomized, parallel-group, non-inferiority trial with twenty consecutive patients eligible for TRbx. Participants were randomized to undergo TRbx using either FNP2 or a standard Tru-Cut needle. The primary outcome was difference in mean biopsy lengths measured by the pathologist. FNP2 biopsy lengths ≤1.35 mm of the standard needle length were considered non-inferior. Secondary outcomes were biopsy length in the needle chamber and immediately after removal, biopsy quality, biopsy fragmentation, patient discomfort/pain, and complications (immediate and after 14 and 30 days).

RESULTS

Mean pathologist-measured FNP2 biopsy length was non-inferior compared to the standard Tru-Cut needle (0.02 mm longer, 95%CI-0.73 to 0.76 mm). Biopsy length in the needle chamber and immediately after removal were also non-inferior. Biopsy quality and patient discomfort were not significantly different for the FNP2 and the standard Tru-Cut needle. Biopsy fragmentation was more common in the FNP2 group.

CONCLUSIONS

The FNP2 biopsy needle is non-inferior to the Tru-Cut needle in terms of biopsy length and not significantly different in terms of biopsy quality and patient experience. Future studies will evaluate the Forsvall needle design's effect on post-biopsy infection risk.

Prostate Biopsy Processing

OBJECTIVES

Current protocols for processing multiple prostate biopsy cores per case are uneconomical and cumbersome. Tissue fragmentation and loss compromise cancer diagnosis. We sought to study an alternate method to improve processing and diagnosis of prostate cancer.

METHODS

Two sets of sextant biopsy specimens from near-identical locations were obtained ex vivo from 48 prostate specimens. One set was processed in the standard fashion while the other was processed using the BxChip, a proprietary biomimetic matrix that accommodates six cores on a single chip. Parameters including grossing, embedding, sectioning and reading time, length of tissue, and degree of fragmentation were compared.

RESULTS

A significant reduction (more than threefold) in preanalytical and analytical time was observed using the multiplex method. Nonlinear fragmentation was absent, in contrast to standard processing.

CONCLUSIONS

The BxChip reduced tissue fragmentation and increased efficiency of prostate biopsy diagnosis. It also resulted in overall cost savings and significantly increased tissue length.

The impact of core length on prostate cancer diagnosis during a standard 14-core prostate biopsy scheme

INTRODUCTION

Even if many studies in the literature purposed to evaluate the improvement of the prostate biopsy (PBx), few studies assessed the diagnostic value of core length in PBx. In this study, we evaluated the length of needle cores sampled during transrectal PBx (TRUSBx) and its impact on cancer diagnosis in a standard 14-core scheme.

METHODS

Medical records of 573 patients who underwent an initial TRUSBx with 14-cores scheme for suspicious prostate cancer (PCa) at our Department were reviewed. The PBx procedure and pathological evaluation were standardized. Cores lengths were compared in patients with versus without cancer, and were divided into group A and B, respectively. Statistical analysis was done to define an acceptable cut-off for biopsy length.

RESULTS

The mean age of the entire cohort was 62.1 ± 7.2 years, while median total prostate-specific antigen (PSA) and prostate volume were 4.2 ng/ml and 44.7 ml, respectively. PCa was showed in 33.3% of patients. Mean core length in group A versus B was 11.9 ± 3.9 versus 11.1 ± 3.2 mm (p = 0.016). Thus, core lengths were significantly longer in patients with cancer. There were no statistically significant differences when we considered the whole length of cores sampled from the right lobe (p = 0.58) and left lobe (p = 0.34).

CONCLUSIONS

The cancer detection rates in cores may be increased by core length in PCa patients during a TRUSBx. Our results suggest a core length of greater than 11.8 mm as a cut-off for quality warranty.

Urologist's Impact on Needle Core Prostate Biopsy Histopathologic Variables Within a Single Institution

OBJECTIVE

To assess the urologist's impact on prostate needle core biopsy variables including number of containers submitted, total core length, longest core length, and individual core length threshold values, and to elucidate the relationship between these variables and cancer detection rate within a recent cohort.

METHODS

A retrospective search was performed to identify patients who had an extended transrectal ultrasound-guided prostate needle core biopsy between 2008 and 2013.

RESULTS

One thousand one prostate biopsies were analyzed. Total core length (mean 13.2-22.9 cm, P < .001) significantly varied by submitting urologist but did not impact cancer detection rate per case. Increased core length per container impacted the cancer detection per container (P < .001). The number of cores that met threshold values of 0.5, 1.0, and 1.5 cm as well as longest individual core length (mean 1.7-2.2 cm) significantly varied between urologist (P < .001), although there was no association between these variables and cancer detection. Container number differed significantly between urologists (P < .001) but did not correlate with cancer detection. For the single urologist with a change in his submission protocol during the study period, a nonsignificant change in cancer detection was noted when comparing 12-14 containers vs 6-9 containers.

CONCLUSION

Submitting urologist significantly impacts prostate biopsy metrics. An increased amount of tissue per container was associated with higher rates of cancer per container. A nonsignificant change in cancer detection rate was observed when container number was reduced from 12-14 to 6-9.

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.

Needle biopsy size and pathological Gleason Score diagnosis: No evidence for a link

BACKGROUND

Biopsy Gleason score (GS), in combination with other clinical parameters, is important to take a therapeutic decision for patients with diagnosis of localized prostate cancer. However, preoperative GS is often upgraded after a radical prostatectomy. Increasing the amount of tissue in prostate biopsy may be a way to avoid this issue. We evaluate the influence of a larger biopsy needle size on the concordance between biopsy and pathological GS.

METHODS

We analyzed paired biopsies and prostatectomy specimens from 104 cases of men with clinically localized prostate cancer. At the time of prostate biopsy, the patients were prospectively randomized into two needle groups (16-Gauge [G] and 18G) using a 1:1 ratio. GS concordance was estimated performing kappa statistic testing, overall concordance rate and risk to under grade biopsy GS=6. A logistic regression analysis was performed to evaluate the patients' characteristics as possible risk factors.

RESULTS

The overall concordance between prostate biopsy and pathological GS was 76.9% and 75.6% (p = 0.875) and the k values were 0.821 and 0.811 (p = 0.424), respectively, for 16G and 18G needle study groups. The risk to undergrade a biopsy GS=6 was 21.1% and 15.4% (p = 0.709) using a 16G and 18G needle, respectively. Age, prostate-specific antigen, prostate volume and needle calibre were not independently associated with a higher risk of GS discordance.

CONCLUSIONS

Needle size does not affect the concordance between biopsy and pathological GS. Although GS is not the only way to determine treatment, it is still an unresolved urological issue.

Optimization of initial prostate biopsy in clinical practice: sampling, labeling and specimen processing

PURPOSE

An optimal prostate biopsy in clinical practice is based on a balance among adequate detection of clinically significant prostate cancers (sensitivity), assuredness regarding the accuracy of negative sampling (negative predictive value), limited detection of clinically insignificant cancers and good concordance with whole gland surgical pathology results to allow accurate risk stratification and disease localization for treatment selection. Inherent within this optimization is variation of the core number, location, labeling and processing for pathological evaluation. To date, there is no consensus in this regard. The purpose of this review is to 1) define the optimal number and location of biopsy cores during primary prostate biopsy among men with suspected prostate cancer, 2) define the optimal method of labeling prostate biopsy cores for pathological processing which will provide relevant and necessary clinical information for all potential clinical scenarios, and 3) determine the maximal number of prostate biopsy cores allowable within a specimen jar which would not preclude accurate histological evaluation of the tissue.

MATERIALS AND METHODS

A bibliographic search using PubMed® covering the period up to July 2012 yielded approximately 550 articles. Articles were reviewed and categorized based on which of the 3 objectives of this review was addressed. Data were extracted, analyzed and summarized. Recommendations are provided based on this literature review and our clinical experience.

RESULTS

The use of 10 to 12-core extended sampling protocols increases cancer detection rates compared to traditional sextant sampling methods and reduces the likelihood of repeat biopsy by increasing negative predictive value, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12, the increase in diagnostic yield becomes marginal. Only limited evidence supports the use of initial biopsy schemes involving more than 12 cores or saturation. Apical and laterally directed sampling of the peripheral zone increases cancer detection rate, reduces the need for repeat biopsies and predicts pathological features on prostatectomy while transition zone biopsies do not. There are little data to suggest that knowing the exact site of an individual positive biopsy core provides meaningful clinical information. However, determining laterality of cancer on biopsy may be helpful for predicting sites of extracapsular extension and therapeutic planning. Placement of multiple biopsy cores in a single container (greater than 2) appears to compromise pathological evaluation, which can reduce cancer detection rate and increase the likelihood of equivocal diagnoses.

CONCLUSIONS

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoids repeat biopsy, and provides information adequate for identifying men who need therapy and planning that therapy while minimizing the detection of occult, indolent prostate cancers. This literature review does not provide compelling evidence that individual site specific labeling of cores benefits clinical decision making regarding the management of prostate cancer. Based on the available literature, we recommend packaging no more than 2 cores in each jar to avoid reduction of the cancer detection rate through inadequate tissue sampling.

Numerical fidelity of endoscopic biopsy fragments in the processing sequence of a university surgical pathology laboratory

CONTEXT

Diagnostic specimens in surgical pathology are, in general, becoming smaller and smaller, as minimally invasive surgical procedures are used to obtain representative tissue. Conservation and effective utilization of small biopsy tissue is therefore crucial in the pathology laboratory.

OBJECTIVE

To identify potential areas where biopsy tissue may be lost in the course of processing in our university-based laboratory.

DESIGN

We followed 2934 endoscopic biopsy samples as they moved through our grossing area and histology laboratory by documenting the number of fragments inked and placed within tissue paper at the time of gross assessment, the number of fragments found in each cassette after processing and subsequently embedded in paraffin, and the number of pieces of tissue present on glass slides after staining.

RESULTS

In 805 (27.4%) cases, the number of fragments of tissue noted on glass slides containing 2 levels of the paraffin block differed from the number submitted in the tissue cassette. Of these, most (137, 17%) differed between the number of fragments embedded in paraffin and those identified on glass slides. Loss of tissue fragments occurred in only 7.2% of cases, while 26.3% had gains in tissue fragments.

CONCLUSIONS

Recognition of type(s) and source(s) of variation in biopsy fragment numbers is important in quality control and in the overall practical management of a histology laboratory.

Preoperative nomograms incorporating magnetic resonance imaging and spectroscopy for prediction of insignificant prostate cancer

Study Type--Prognosis (case series). Level of Evidence 4. What's known on the subject? And what does the study add? Nomograms are available that combine clinical and biopsy findings to predict the probability of pathologically insignificant prostate cancer in patients with clinically low-risk disease. Based on data from patients with Gleason score 6, clinical stage ≤ T2a and PSA <20 ng/ml, our group developed the first nomogram models for predicting insignificant prostate cancer that incorporated clinical data, detailed biopsy data and findings from MRI or MRI/MRSI (BJU Int. 2007;99(4):786-93). When tested retrospectively, these MR models performed significantly better than standard clinical models with and without detailed biopsy data. We prospectively validated the previously published MR-based nomogram models in a population of patients with Gleason score 6, clinical stage ≤ T2a and PSA <10 ng/ml. Based on data from this same population, we also developed two new models for predicting insignificant prostate cancer that combine MR findings and clinical data without detailed biopsy data. Upon initial testing, the new MR models performed significantly better than a clinical model lacking detailed biopsy data.

OBJECTIVES

• To validate previously published nomograms for predicting insignificant prostate cancer (PCa) that incorporate clinical data, percentage of biopsy cores positive (%BC+) and magnetic resonance imaging (MRI) or MRI/MR spectroscopic imaging (MRSI) results. • We also designed new nomogram models incorporating magnetic resonance results and clinical data without detailed biopsy data. Nomograms for predicting insignificant PCa can help physicians counsel patients with clinically low-risk disease who are choosing between active surveillance and definitive therapy.

PATIENTS AND METHODS

• In total, 181 low-risk PCa patients (clinical stage T1c-T2a, prostate-specific antigen level <10 ng/mL, biopsy Gleason score of 6) had MRI/MRSI before surgery. • For MRI and MRI/MRSI, the probability of insignificant PCa was recorded prospectively and independently by two radiologists on a scale from 0 (definitely insignificant) to 3 (definitely significant PCa). • Insignificant PCa was defined on surgical pathology. • There were four models incorporating MRI or MRI/MRSI and clinical data with and without %BC+ that were compared with a base clinical model without %BC and a more comprehensive clinical model with %BC+. Prediction accuracy was assessed using areas under receiver-operator characteristic curves.

RESULTS

• At pathology, 27% of patients had insignificant PCa, and the Gleason score was upgraded in 56.4% of patients. • For both readers, all magnetic resonance models performed significantly better than the base clinical model (P ≤ 0.05 for all) and similarly to the more comprehensive clinical model.

CONCLUSIONS

• Existing models incorporating magnetic resonance data, clinical data and %BC+ for predicting the probability of insignificant PCa were validated. • All MR-inclusive models performed significantly better than the base clinical model.

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.

The impact of core biopsy fragmentation in prostate cancer

OBJECTIVES

Since accurate tumor localization and quantification are essential requisites avoiding prostate cancer overtreatment, we analyzed the impact of core fragmentation and the relation between core biopsy taken and pathological information in regard to cancer extension and aggressiveness (Gleason score).

METHODS

One hundred and ninety-nine men submitted to trans-rectal prostate biopsy by the same urologist between October 2006 and October 2008 were included, and the number of cores obtained by biopsy compared to the number of cores examined by the same pathologist.

RESULTS

Total core number obtained by biopsy was 21.54 (± 3.56) compared to 24.08 (± 4.77) examined by the pathologist, P < 0.01. Dividing prostate gland by areas such as base, mid and apical right and left, all areas showed statistically different core number between biopsy and pathological examination report (P < 0.01). Mean ratio of positive core cancer length was 0.41 (± 0.12) and 0.32 (± 0.8) comparing individual and overall cores analysis, respectively (P < 0.01). The mean Gleason score in the individual and overall cores analysis were 6.6 (6-9) and 6.3 (6-9), respectively, P < 0.01.

CONCLUSIONS

Considering the ongoing trend for earlier diagnosis of increasing numbers of younger men with low-risk prostate cancer, this study is original and demonstrates the possibility of core fragmentation, explaining in part over- and under-staging. One core per container and an overall Gleason score and percentage of adenocarcinoma for each container are encouraged.