Current prostate biopsy interpretation: criteria for cancer, atypical small acinar proliferation, high-grade prostatic intraepithelial neoplasia, and use of immunostains

Clinical strategy of repeat biopsy in patients with atypical small acinar proliferation (ASAP)

Atypical small acinar proliferation (ASAP) occurs in approximately 5% of prostate biopsies. Approximately 30–40% of patients with ASAP have biopsy detectable prostate cancer (PCa) within 5 years. Current guidelines recommend a repeat biopsy within 3–6 months after the initial diagnosis. The aim of the present study was to examine the association between ASAP and subsequent diagnosis of clinically significant PCa (csPCa). The need for immediate repeat biopsy was also evaluated. We identified 212 patients with an ASAP diagnosis on their first biopsy at our institution between February 2006 and March 2018. Of these patients, 102 (48.1%) had at least one follow-up biopsy. Clinicopathologic features including rates of subsequent PCa and csPCa were assessed. Thirty-five patients subsequently underwent radical prostatectomy (RP). Their pathologic results were reviewed. csPCa was defined as the presence of Gleason score (GS) ≥ 3 + 4 in ≥ 1 biopsy core. Adverse pathology (AP) was defined as high-grade (primary Gleason pattern ≥ 4) or non-organ-confined disease (pT3/N1) after RP. Of 102 patients, 87 (85.3%), 13 (12.7%), and 2 (2.0%) had one, two, and three follow-up biopsies, respectively. Median time from the initial ASAP diagnosis to the 2nd follow-up biopsy and the last follow-up biopsy were 21.9 months (range 1–129 months) and 27.7 months (range 1–129 months), respectively. Of these patients, 46 (45.1%) were subsequently diagnosed with PCa, including 20 (19.6%) with csPCa. Only 2 (2.0%) patients had GS ≥ 8 disease. Five (4.9%) patients had number of positive cores > 3. Of 35 patients who subsequently underwent RP, seven (20%) had AP after RP and 17 (48.6%) showed GS upgrading. Of these 17 patients, the vast majority (16/17, 94.1%) had GS upgrading from 3 + 3 to 3 + 4. 45.1% of patients with an initial diagnosis of ASAP who had repeat prostate biopsy were subsequently diagnosed with PCa and 19.6% were found to have csPCa. Our findings add further evidence that after a diagnosis of ASAP, a repeat biopsy is warranted and that the repeat biopsy should not be postponed.

Immunohistochemistry for Prostate Biopsy-Impact on Histological Prostate Cancer Diagnoses and Clinical Decision Making

BACKGROUND

To test the value of immunohistochemistry (IHC) staining in prostate biopsies for changes in biopsy results and its impact on treatment decision-making.

METHODS

Between January 2017-June 2020, all patients undergoing prostate biopsies were identified and evaluated regarding additional IHC staining for diagnostic purpose. Final pathologic results after radical prostatectomy (RP) were analyzed regarding the effect of IHC at biopsy.

RESULTS

Of 606 biopsies, 350 (58.7%) received additional IHC staining. Of those, prostate cancer (PCa) was found in 208 patients (59.4%); while in 142 patients (40.6%), PCa could be ruled out through IHC. IHC patients harbored significantly more often Gleason 6 in biopsy (p < 0.01) and less suspicious baseline characteristics than patients without IHC. Of 185 patients with positive IHC and PCa detection, IHC led to a change in biopsy results in 81 (43.8%) patients. Of these patients with changes in biopsy results due to IHC, 42 (51.9%) underwent RP with 59.5% harboring ≥pT3 and/or Gleason 7-10.

CONCLUSIONS

Patients with IHC stains had less suspicious characteristics than patients without IHC. Moreover, in patients with positive IHC and PCa detection, a change in biopsy results was observed in >40%. Patients with changes in biopsy results partly underwent RP, in which 60% harbored significant PCa.

[What primary care physicians should know about new markers in prostate cancer]

The use of prostate-specific antigen as a diagnostic tool in the screening of prostate cancer is reflected in an increase in the incidence, an increase in diagnosis at initial stages, and an increase in radical therapies, even at the expense of over-treatment in some cases. It is known from the data collected in the literature that not every patient with high prostate-specific antigen needs a biopsy, and that not every patient diagnosed with prostate cancer needs treatment. With the new emerging prostate markers, we will try to improve the specificity of prostate-specific antigen in the grey area (4-10 ng/ml) should be improved. This should avoid unnecessary biopsies. The sensitivity in the detection of significant prostate cancer with low prostate-specific antigen should also be improved in an attempt to reduce the risk of over-treatment. On the other hand, prognostic biomarkers with genomic tests will help to choose the best therapeutic option for the patient.

Atypical Small Acinar Proliferation and High Grade Prostatic Intraepithelial Neoplasia: Should We Be Concerned? An Observational Cohort Study with a Minimum Follow-Up of 3 Years

Introduction

Atypical small acinar proliferation (ASAP) and high grade prostatic intraepithelial neoplasia (HGPIN) are considered precancerous. We aimed to measure the rate of repeat biopsy and adenocarcinoma in patients with ASAP and HGPIN and identify any clinico-pathologic parameters at diagnosis of ASAP/HGPIN that are predictive of adenocarcinoma.

Materials and Methods

Patients with a diagnosis of ASAP/HGPIN with no previous or concomitant cancer were identified. Prostate specific antigen (PSA) and magnetic resonance imaging (MRI) changes were monitored. Re-biopsy was at clinician discretion.

Results

Nineteen were diagnosed with ASAP and 17 with HGPIN. Seven with ASAP (37%) and 6 with HGPIN (35%) underwent re-biopsy. Three (16%) with ASAP and 5 with HGPIN (29%) were diagnosed with adenocarcinoma. The difference in cancer detection rates between ASAP and HGPIN was not significant (p = 0.35). Five (14%) in total required definitive therapy for adenocarcinoma. Twenty-three (64%) did not undergo repeat biopsy. Parameters at diagnosis of HGPIN and ASAP, including PSA, prostate volume and PSA density, were compared between the cancer and non-cancer cohorts with none found to be predictive of adenocarcinoma.

Conclusion

By monitoring PSA and MRI changes, we managed to spare re-biopsy in two-thirds of patients. Further evaluation is necessary to characterize a surveillance protocol in these populations.

Typing the atypical: Diagnostic issues and predictive markers in suspicious prostate lesions

As much as 5% of prostate biopsies yield findings equivocal for malignancy even for skilled uropathologist; such "grey zone" lesions have been addressed in many ways, although the acronym ASAP (atypical small acinar proliferation) is the most widely used when referring to an atypical focus suspicious, but not diagnostic, for malignancy. Since the introduction of this diagnostic category more than 20 years ago, debate has ensued over its histological characterization and clinical significance. Pathology reporting of ASAP, commonly based on strict morphological criteria and traditional immunohistochemical markers such as basal cell antibodies, has been improved by recent availability of novel immunohistochemical markers such as AMACR and ERG. Further pathological issues, such as the role of pre-analytical variables, number of tissue levels, interobserver variability, and association with prostatic intraepithelial neoplasia also play a role in the optimal assessment of ASAP. Apart from diagnostic issues, a major issue is ASAP predictive value for prostate cancer on repeat biopsy. Therefore, attempts have been made to identify clinical and biological parameters that could predict subsequent diagnosis of malignancy as well as define time and modality of repeat biopsy. Finally, pathological features of cancers detected after a previous ASAP diagnosis are compared with those diagnosed at first prostate biopsy.

Randomized, Placebo-Controlled Trial of Green Tea Catechins for Prostate Cancer Prevention

Preclinical, epidemiologic, and prior clinical trial data suggest that green tea catechins (GTC) may reduce prostate cancer risk. We conducted a placebo-controlled, randomized clinical trial of Polyphenon E (PolyE), a proprietary mixture of GTCs, containing 400 mg (-)-epigallocatechin-3-gallate (EGCG) per day, in 97 men with high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP). The primary study endpoint was a comparison of the cumulative one-year prostate cancer rates on the two study arms. No differences in the number of prostate cancer cases were observed: 5 of 49 (PolyE) versus 9 of 48 (placebo), P = 0.25. A secondary endpoint comparing the cumulative rate of prostate cancer plus ASAP among men with HGPIN without ASAP at baseline, revealed a decrease in this composite endpoint: 3 of 26 (PolyE) versus 10 of 25 (placebo), P < 0.024. This finding was driven by a decrease in ASAP diagnoses on the Poly E (0/26) compared with the placebo arm (5/25). A decrease in serum prostate-specific antigen (PSA) was observed on the PolyE arm [-0.87 ng/mL; 95% confidence intervals (CI), -1.66 to -0.09]. Adverse events related to the study agent did not significantly differ between the two study groups. Daily intake of a standardized, decaffeinated catechin mixture containing 400 mg EGCG per day for 1 year accumulated in plasma and was well tolerated but did not reduce the likelihood of prostate cancer in men with baseline HGPIN or ASAP.

Atypical Small Acinar Proliferation: Repeat Biopsy and Detection of High Grade Prostate Cancer

Purpose. Atypical small acinar proliferation (ASAP) is diagnosed in 1-2% of prostate biopsies. 30–40% of patients with ASAP may be diagnosed with prostate cancer (PCa) on repeat biopsy. Our objective was to examine the association between ASAP and subsequent diagnosis of intermediate/high risk PCa. Materials and Methods. Ninety-six patients who underwent prostate biopsy from 2000 to 2013 and were diagnosed with ASAP were identified. Clinicopathologic features were analyzed. Comparison was made between those with subsequent PCa on repeat biopsy and those with benign repeat pathology. Results. 56/96 (58%) patients had a repeat biopsy. 22/56 (39%) were subsequently diagnosed with PCa. There was no significant difference in patients' characteristics. Presence of HGPIN on initial biopsy was associated with a benign repeat biopsy (68% versus 23%). 17/22 (77%) had Gleason grade (GG) 3+3 disease and only 5/22 (23%) had GG 3+4 disease. Conclusions. 22/56 patients (39%) of patients who underwent a subsequent prostate biopsy following a diagnosis of ASAP were found to have PCa. 77% of these men were diagnosed with GG 3+3 PCa. Only 23% were found to have intermediate risk PCa and no high risk PCa was identified. Immediate repeat prostate biopsy in patients diagnosed with ASAP may be safely delayed. A multi-institutional cohort is being analyzed.

Gleason drift in the NIHR ProtecT study

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

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.

Single foci prostate cancer: current diagnosis and management

Diagnosis of small prostate cancer foci is a real challenge for pathologists and urologists as it carries the risk of false positive or negative diagnosis with clinical consequences. Diagnosis of small prostate cancer foci requires a strict methodological approach which includes a search for major and minor features under low and high magnification. Ambiguous cases can be further clarified with the use of basal cell immunomarkers complemented by a positive indicator of malignancy. Despite the new diagnostic armamentarium, a few cases will continue to remain doubtful and might require an appropriate rebiopsy.

Molecular Targeted Therapies Using Botanicals for Prostate Cancer Chemoprevention

In spite of the large number of botanicals demonstrating promise as potential cancer chemopreventive agents, most have failed to prove effectiveness in clinical trials. Critical requirements for moving botanical agents to recommendation for clinical use include adopting a systematic, molecular-target based approach and utilizing the same ethical and rigorous methods that are used to evaluate other pharmacological agents. Preliminary data on a mechanistic rationale for chemoprevention activity as observed from epidemiological, in vitro and preclinical studies, phase I data of safety in suitable cohorts, duration of intervention based on time to progression of pre-neoplastic disease to cancer and using a valid panel of biomarkers representing the hypothesized carcinogenesis pathway for measuring efficacy must inform the design of clinical trials. Botanicals have been shown to influence multiple biochemical and molecular cascades that inhibit mutagenesis, proliferation, induce apoptosis, suppress the formation and growth of human cancers, thus modulating several hallmarks of carcinogenesis. These agents appear promising in their potential to make a dramatic impact in cancer prevention and treatment, with a significantly superior safety profile than most agents evaluated to date. The goal of this paper is to provide models of translational research based on the current evidence of promising botanicals with a specific focus on targeted therapies for PCa chemoprevention.

[Utility of seriated sections in prostate biopsies]

INTRODUCTION

With the routine use of prostate specific antigen, focal carcinomas and atypical small acini proliferation (ASAP) are currently detected more frequently. The number of sections per cylinder needed to detect most of them is still unknown.

METHODS

We reviewed 250 sextant prostate biopsies in the 2008-2011 period. The average number of cylinders per biopsy was 14. In each case, in addition to the original sections with three histological levels, three more sections were performed with three levels (total: 12 levels). Biopsies with focal lesion were analyzed immunohistochemically. The frequency of focal lesions was compared to a previous study of 1000 biopsies in which a single section was made with three histological levels. The main clinical and laboratory data were recorded.

RESULTS

There were 16 focal lesions (6.4%). Seven (2.8%) corresponded to focal carcinomas and nine (3.6%) to atypical proliferation. In the previous study, thirteen (1.3%) focal carcinomas and 29 (2.9%) cases with atypical proliferation were found.

CONCLUSIONS

There was an increase of 4.2% to 6.4% of focal lesions carcinomas increased from 1.3% to 2.8%. Making additional sections in all biopsies may have practical drawbacks. However, they could be performed in patients with high clinical suspicion of carcinoma (especially in young patients), or when there is a history of atypical glandular proliferations consistent with carcinoma in previous biopsies.

Comparative analysis of three- and two-antibody cocktails to AMACR and basal cell markers for the immunohistochemical diagnosis of prostate carcinoma

Background

Immunohistochemistry using antibody cocktails against basal cell specific and cancer-associated markers is important in the diagnosis of prostate carcinoma in needle biopsies. We compared the usefulness for detecting prostate carcinoma of a three-marker cocktail of antibodies to α-methylacyl-CoA racemase (AMACR), p63 and cytokeratin (CK) 5 with a traditional two-marker cocktail of AMACR and p63.

Methods

Sixty-six prostate needle biopsies were analysed prospectively. Serial sections were immunostained with the two- and three- antibody cocktails. Blinded slides were assessed individually by two pathologists and sensitivity, specificity and kappa statistics were calculated.

Results

Both antibody cocktails contributed to the detection of prostate carcinoma in needle biopsies. There was an acceptable level of agreement between the pathologists for both the cocktails. Sensitivity was similar for one pathologist comparing both the cocktails (76.4% and 75.7%), but was slightly lower comparing the three-antibody with the two-antibody cocktail for the other pathologist (66.6% vs. 77.4%, respectively). Higher specificity values of 90.3% were achieved by both pathologists using three-antibody as compared with two-antibody cocktails (68.7% and 71.8%).

Conclusions

Antibody cocktails are important in diagnosing prostate carcinoma in needle biopsies. Adding an extra basal cell marker to the traditional two-antibody cocktail improves the specificity of detecting prostate carcinoma in limited needle biopsy material, and should be considered for routine diagnostic use.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2492231327330327

Prostate Cancer Chemoprevention Targeting Men with High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) and Atypical Small Acinar Proliferation (ASAP): Model for Trial Design and Outcome Measures

In spite of the large number of nutrient-derived agents demonstrating promise as potential chemopreventive agents, most have failed to prove effectiveness in clinical trials. Critical requirements for moving nutrient-derived agents to recommendation for clinical use include adopting a systematic, molecular-mechanism based approach and utilizing the same ethical and rigorous methods such as are used to evaluate other pharmacological agents. Preliminary data on a mechanistic rationale for chemoprevention activity as observed from epidemiological, in vitro and preclinical studies, phase I data of safety in suitable cohorts, duration of intervention based on time to progression of preneoplastic disease to cancer and the use of a valid panel of biomarkers representing the hypothesized carcinogenesis pathway for measuring efficacy must inform the design of phase II clinical trials. The goal of this paper is to provide a model for evaluating a well characterized agent- Polyphenon E- in a phase II clinical trial of prostate cancer chemoprevention.

Challenges and potential solutions to meeting accrual goals in a Phase II chemoprevention trial for prostate cancer

OBJECTIVE

The goal of this report is to describe the on going strategies, successes, challenges and solutions for recruitment in this multi-center, phase II chemoprevention trial targeting men at high risk for prostate cancer.

METHODS

We developed and implemented a multi-center clinical trial in institutions with supportive infrastructure, lead by a recruitment team of experienced and committed physicians and clinical trial staff, implementing multi-media and community outreach strategies to meet recruitment goals. Screening logs were reviewed to identify trends as well as patient, protocol and infrastructure -related barriers impacting accrual and revisions to protocol implemented.

RESULTS

Between January 2008 and February 2011 a total of 3547 individuals were prescreened with 94% (n=3092) determined to be ineligible based on diagnosis of cancer or benign biopsy results. Of these, 216 were considered eligible for further screening with 52% (n=113) declining to participate due to patient related factors and 14% (n=29) eliminated due to protocol-related criteria for exclusion. Ninety-four (94) subjects consented to participate with 34% of these subjects (n=74) meeting all eligibility criteria to be randomized to receive study agent or placebo. Across all sites, 99% of the recruitment of subjects in this clinical trial is via physician recruitment and referral with less than 1% responding to other recruitment strategies.

CONCLUSION

A contemporary approach to subject recruitment and frequent evaluation is needed to assure responsiveness to emerging challenges to accrual and the evolving scientific literature. A focus on investing on improving systems for physician recruitment may be key to meeting recruitment target in chemoprevention trials.

The use of immunohistochemistry for diagnosis of prostate cancer

PURPOSE

Atypical glands (ASAP) are diagnosed in 5.0% of prostate biopsies, and cancer identification in a rebiopsy is higher than 40.0%. The use of antibodies to mark basal cells is currently a common practice, in order to avoid rebiopsies. There has been no reported study that has reviewed characteristics of radical prostatectomies (RPs) when immunohistochemistry (IHC) was necessary for definitive diagnosis.

MATERIALS AND METHODS

Out of 4127 biopsies examined from 2004 to 2008, 144 (3.5%) were diagnosed with ASAP. IHC was performed using antibody anti-34ΒE12 and p63. The results of surgical specimens of 27 patients treated by RP after the diagnosis of prostate cancer (PC) was made using IHC (Group 1) were compared with 1040 patients where IHC was not necessary (Group 2).

RESULTS

IHC helped to diagnose PC in 103 patients (71.5%). Twenty-seven (26.2%) underwent RP. In Group 1, two (7.4%) adenocarcinomas were insignificant versus 29 (2.9%) for Group 2. Patients from Group 1 were younger (p = 0.039), had lower Gleason scores (GS) (p < 0.001), lower percentage of Gleason pattern 4 (p < 0.001), and smaller tumors (p < 0.001).

CONCLUSION

The use of IHC did not lead to diagnosis of insignificant tumors as illustrated by absence of differences in pathological stage or positive surgical margins in men submitted to RP. Therefore, our results suggest that this modality should be routinely used for a borderline biopsy and ASAP cases.

Is there a role for fatty acid synthase in the diagnosis of prostatic adenocarcinoma?: A comparison with AMACR

Our aim was to compare the usefulness of fatty acid synthase (FASn) with that of α-methylacyl coenzyme-A racemase (AMACR) in the diagnosis of prostatic adenocarcinoma. The expression of these 2 markers was compared in a tissue microarray containing 62 foci of benign glands and 36 foci of prostatic adenocarcinoma. Similar to AMACR, there was significantly higher FASn expression in adenocarcinoma compared with that in benign glands. The optimal accuracy rate and area under curve (AUC) by receiver operating characteristic analysis for FASn were not significantly different from those for AMACR (accuracy, 80% vs 87%; AUC, 0.942 vs 0.956; P for both, > .05). Moreover, in cases with coexistent malignant and benign glands on the same core, FASn could selectively distinguish a proportion of cases (17/21 [81%]) similar to using AMACR. We conclude that FASn may aid in the diagnosis of prostatic adenocarcinoma, at least to supplement AMACR as another positive marker of carcinoma and potentially increase diagnostic accuracy.

Prostate gland biopsies and prostatectomies: an Ontario community hospital experience

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

α-Methylacyl-CoA racemase spliced variants and their expression in normal and malignant prostate tissues

OBJECTIVES

To evaluate the possibility of using α-methylacyl-CoA racemase (AMACR) variants to improve the specificity of prostate cancer (CaP) detection. AMACR has been used as a diagnostic biomarker for CaP and is now a standard biomarker for needle biopsy specimens with ambiguous lesions.

METHODS

We used in silico analysis and molecular cloning to discover new AMACR variants and quantitative reverse transcription-polymerase chain reaction (RT-PCR) to measure the transcript levels of AMACR and its variants in 4 prostate cell lines and in 23 pairs of CaP and adjacent normal tissue.

RESULTS

We found 4 novel variants, IAs, IBL, IBLd, and IBLi. Transcript levels of most AMACR variants were significantly upregulated in CaP compared with its adjacent normal counterparts. A variants, the functional variants based on bioinformatic analysis, showed levels of transcript expression in CaP in this order: IA≫IAd=IIA≫IIAs>IAs. In contrast, the expression of the B variants, which appear to be nonfunctional due to the absence of exon 3, was lower than that of the A variants. IB was the most abundant form of B variant; and expression of IIB was negligible. More important, the difference between levels of variant IA, IAd, IIA, IIAs, IB, and IBLi in CaP and normal tissue was significantly higher than the difference in levels of total AMACR.

CONCLUSIONS

Our data suggest that AMACR variants have better power than total AMACR in discriminating between CaP and adjacent normal tissue. These findings may be useful for the development of future diagnostic assays.

Predictive factors of prostate cancer at repeat biopsy in patients with an initial diagnosis of atypical small acinar proliferation of the prostate

Purpose

The factors that predict prostate cancer detection on repeat biopsy were evaluated in patients with atypical small acinar proliferation (ASAP) on the initial biopsy.

Materials and Methods

From 2003 to 2008, 3,130 men with suspected prostate cancer underwent a prostate needle biopsy, and 244 (7.8%) were diagnosed as having ASAP. One hundred seventy of 244 patients were rebiopsied at least once more. They were classified into a prostate cancer group and a noncancer group according to the final pathological diagnosis. The database of rebiopsied patients included age, initial prostate-specific antigen (PSA), PSA density (PSAD), PSA velocity (PSAV), total prostate volume (TPV), and transitional zone volume of the prostate (TZV). We compared differences in the aforementioned parameters between the 2 groups.

Results

A total of 57 patients (33.5%) with ASAP were ultimately shown to have prostate cancer. Univariate analysis showed that PSAD (p=0.002), PSAV (p=0.001), TPV (p=0.035), and TZV (p=0.005) differed significantly between the cancer and noncancer groups. The results of the multivariate analysis showed that PSAD (p=0.022), PSAV (p<0.001), and TPV (p=0.037) had a statistically significant correlation with cancer detection.

Conclusions

PSAD, PSAV, and TPV are predictive factors of prostate cancer in patients with an initial diagnosis of ASAP of the prostate. Although repeat biopsy is mandatory irrespective of PSA values, the follow-up of PSA may help to estimate the probability of cancer in these men.

Improved resolution of diagnostic problems in selected prostate needle biopsy specimens by using the ASAP workup: a prospective study of interval sections vs new recut sections

This study assessed the value of an atypical small acinar proliferation (ASAP) workup consisting of preparing new recut sections from the paraffin block and performing H&E-stained sections and immunostains (using the antibody cocktail for p63, cytokeratins 5 and 14, and alpha-methylacyl coenzyme A racemase) on the slides. We compared the ASAP workup with the interval workup, the common practice of performing the same immunostains on the saved interval sections, in 105 cases because of focal glandular atypia on the original H&E-stained sections. There were no specimens in which only the interval workup showed a changed diagnosis, but there were 23 specimens (21.9%) in which the preliminary diagnosis was changed to a definitive diagnosis of carcinoma (10 specimens) or a specific benign diagnosis (13 specimens) based solely on the findings of the ASAP workup. The ASAP workup is recommended as a very useful histologic tool for resolving diagnostic problems in prostate needle biopsy specimens.

Pathologic results of radical prostatectomies in patients with simultaneous atypical small acinar proliferation and prostate cancer

PURPOSE

The incidence of adenocarcinoma on a subsequent biopsy following a diagnosis of atypical small acinar proliferation (ASAP) ranges from 34% to 60%. We reexamined radical prostatectomy (RP) specimens of patients diagnosed as having synchronous ASAP with prostate cancer (PCa) to evaluate pathological entities and the clinical significance of ASAP.

MATERIALS AND METHODS

From January 2007 to December 2008, a total of 118 patients who had been diagnosed with adenocarcinoma on prostate needle biopsy underwent RP. Forty-six of the 118 patients (39%) were diagnosed as having synchronous ASAP with PCa on the prostate needle biopsy. Using whole-mount sections and prostate mapping, we evaluated the RP specimens that were close sections to the ASAP on prostate needle biopsy. All tissues were examined by immunohistochemistry with high molecular weight cytokeratin (34betaE12), p63, and AMACR/P504S added to initial H&E stains by one pathologist.

RESULTS

Thirty-six of the 46 patients (78%) were diagnosed as having adenocarcinoma at sites of ASAP on the initial prostate needle biopsies. The Gleason score was 5 to 6 in 22 patients (61%), 7 in 3 (8%), and unknown due to multifocal and microfocal lesions in 11 (31%). The tumor volume of 14 of the 36 patients (39%) was 0.5 cc or less and was unknown due to multifocal and microfocal lesions in 8 (22%).

CONCLUSIONS

Most ASAP on initial prostate needle biopsy was a true pathological entity, in other words, prostatic adenocarcinoma. Aggressive approaches including more extended repeat biopsy with additional biopsy of the site of the ASAP are needed to diagnose PCa in patients with ASAP.

What is the pathologist saying? Interpretation of the prostate pathology report

Management of patients presenting with elevated serum prostate-specific antigen levels, or those with previously diagnosed prostate carcinoma, is very much dependent on the pathology report on needle biopsy or radical prostatectomy specimens obtained from these patients. In contrast to a diagnosis of benignity or high-grade prostatic intraepithelial neoplasia, a diagnosis of atypia on needle core biopsy is usually an indication for a repeat biopsy; however, it is important to understand that atypia and other related terms are not specific diagnoses. The pathology report on different prostate specimens with a diagnosis of carcinoma usually includes the Gleason grade and extent of carcinoma among other morphological prognostic and predictive factors. Understanding the significance of these morphological factors and how they are evaluated and incorporated into the pathology report, as well as newer developments in this field, can assist urologists in the interpretation of the pathological findings and ultimately lead to better clinical care.

Best practice in diagnostic immunohistochemistry: prostate carcinoma and its mimics in needle core biopsies

CONTEXT

The unrelenting challenge encountered when differentiating limited-volume prostate carcinoma and sometimes subtle variants from its many morphologic mimics has increased the use of ancillary immunohistochemistry in routine prostate needle biopsies. The availability of prostate cancer-associated and basal cell-associated markers has been an invaluable addition to diagnostic surgical pathology.

OBJECTIVE

To review commonly used immunohistochemical stains, including innovative combinations, for confirmation or differential diagnosis of prostate carcinoma, and to propose appropriately constructed panels using morphologic patterns in prostate needle biopsies.

DATA SOURCES

These best practices are based on our experience with routine and consultative case sign-outs and on a review of the published English-language literature from 1987 through 2008.

CONCLUSIONS

Basal cell-associated markers p63, high-molecular-weight cytokeratin 34 beta E12, cytokeratin 5/6 or a cocktail containing p63 and high-molecular-weight cytokeratin 34 beta E12 or cytokeratin 5/6 and prostate carcinoma-specific marker alpha-methylacyl coenzyme A (coA) racemase alone or in combination are useful adjuncts in confirming prostatic carcinoma that either lacks diagnostic, qualitative or quantitative features or that has an unusual morphologic pattern (eg, atrophic, pseudohyperplastic) or is in the setting of prior treatment. The combination of alpha-methylacyl coA racemase positivity with negative staining for basal cell-associated markers supports a malignant diagnosis in the appropriate morphologic context. Dual chromogen basal cell- associated markers (p63 [nuclear] and high-molecular-weight cytokeratin 34 beta E12/cytokeratin 5/6 [cytoplasmic]) and alpha-methylacyl coA racemase in an antibody cocktail provide greater sensitivity for the basal cell layer, easing evaluation and minimizing loss of representation of the focal area interest because the staining is performed on one slide. In the posttreatment setting, pancytokeratin facilitates detection of subtle-treated cancer cells. Prostate-specific antigen and prostatic acid phosphatase markers are helpful in excluding secondary malignancies involving the prostate, such as urothelial carcinoma, and occasionally in excluding nonprostatic benign mimickers, such as nephrogenic adenoma, mesonephric gland hyperplasia, and Cowper glands. There is no role for ordering immunohistochemistry prospectively in all cases of prostatic needle biopsies.

p63 in prostate biology and pathology

The identification of stem cells and differentiation programs regulating the development and maintenance of the normal prostate epithelium is essential for the identification of the cell type(s) and molecular alterations involved in the development and propagation of prostate cancer (CaP). The p53-homologue p63 is highly expressed in normal prostate basal cells and is a clinically useful biomarker for the diagnosis of CaP. Importantly, p63 has been shown to play a critical role in prostate development. Recent experimental evidence also suggests that this gene is essential for normal stem cell function in the prostate as well as other epithelial organs. Future studies aimed at better defining the role of p63 in the renewal of the adult prostate epithelium are likely to shed new light on the mechanisms involved in prostate carcinogenesis.

Periacinar retraction clefting in proliferative prostatic atrophy and prostatic adenocarcinoma

AIMS

To evaluate the presence and extent of periacinar retraction clefting in proliferative prostatic atrophy and carcinoma in radical prostatectomy specimens.

METHODS

Atrophic foci and neoplastic glands were analysed in specimens from 50 patients who underwent radical prostatectomy. Analysed atrophic glands were classified in two main groups, proliferative atrophy (PA) and proliferative inflammatory atrophy (PIA); each group was subclassified into simple atrophy (SA) and postatrophic hyperplasia (PAH). According to the presence and extent of periacinar retraction clefting, atrophic and neoplastic glands were classified as: group 1, glands without clefts or with clefts affecting 50% of the circumference in <50% of examined glands; and group 3, glands with clefts that affected >50% of the circumference in >or=50% of examined glands.

RESULTS

Forty-four (88.0%) atrophic foci were without periacinar clefts or clefts were present in less than half of the gland circumference (group 1). In 6 (12.0%), atrophic foci clefts affected >50% of gland circumference (groups 2 and 3). Forty-five (90.0%) carcinomas were with clefts which affected more than 50% of gland circumference (groups 2 and 3); and in five carcinomas only, clefts were not found or affected <50% of gland circumference (group 1).

CONCLUSION

Results indicate that periacinar retraction clefting represents a reliable criterion in differential diagnosis between proliferative atrophy and carcinoma.