Intraductal carcinoma of the prostate: precursor or aggressive phenotype of prostate cancer?

Aggressive Prostate Cancer in Patients Treated with Active Surveillance

Active surveillance has emerged as a promising approach for managing low-risk and favorable intermediate-risk prostate cancer (PC), with the aim of minimizing overtreatment and maintaining the quality of life. However, concerns remain about identifying "aggressive prostate cancer" within the active surveillance cohort, which refers to cancers with a higher potential for progression. Previous studies are predictors of aggressive PC during active surveillance. To address this, a personalized risk-based follow-up approach that integrates clinical data, biomarkers, and genetic factors using risk calculators was proposed. This approach enables an efficient risk assessment and the early detection of disease progression, minimizes unnecessary interventions, and improves patient management and outcomes. As active surveillance indications expand, the importance of identifying aggressive PC through a personalized risk-based follow-up is expected to increase.

In-Depth Comparison of Genetic Variants Demonstrates a Close Relationship Between Invasive and Intraductal Components of Prostate Cancer

Intraductal carcinoma (IDC) of the prostate is often associated with concurrent high-grade invasive prostate cancer (PCa) and poor clinical outcomes. In this context, IDC is thought to represent the retrograde spread of invasive prostatic adenocarcinoma into the acini and ducts. Prior studies have demonstrated a concordance of PTEN loss and genomic instability between the IDC and high-grade invasive components of PCa, but larger genomic association studies to solidify our understanding of the relationship between these 2 lesions are lacking. Here, we evaluate the genomic relationship between duct-confined (high-grade prostatic intraepithelial neoplasia and IDC) and invasive components of high-grade PCa using genetic variants generated by whole exome sequencing. High-grade prostatic intraepithelial neoplasia and IDC were laser-microdissected, and PCa and nonneoplastic tissue was manually dissected from 12 radical prostatectomies. A targeted next-generation sequencing panel was used to identify disease-relevant variants. Additionally, the degree of overlap between adjacent lesions was determined by comparing exome-wide variants detected using whole exome sequencing data. Our results demonstrate that IDC and invasive high-grade PCa components show common genetic variants and copy number alterations. Hierarchical clustering of genome-wide variants suggests that in these tumors, IDC is more closely related to the high-grade invasive components of the tumor compared with high-grade prostatic intraepithelial neoplasia. In conclusion, this study reinforces the concept that, in the context of high-grade PCa, IDC likely represents a late event associated with tumor progression.

In situ expression of ERG protein in the context of tumor heterogeneity identifies prostate cancer patients with inferior prognosis

Prognostic biomarkers for prostate cancer are needed to improve prediction of disease course and guide treatment decisions. However, biomarker development is complicated by the common multifocality and heterogeneity of the disease. We aimed to determine the prognostic value of candidate biomarkers transcriptional regulator ERG and related ETS family genes, while considering tumor heterogeneity. In a multisampled, prospective, and treatment‐naïve radical prostatectomy cohort from one tertiary center (2010–2012, median follow‐up 8.1 years), we analyzed ERG protein (480 patients; 2047 tissue cores), and RNA of several ETS genes in a subcohort (165 patients; 778 fresh‐frozen tissue samples). Intra‐ and interfocal heterogeneity was identified in 29% and 33% (ERG protein) and 39% and 27% (ETS RNA) of patients, respectively. ERG protein and ETS RNA was identified exclusively in a nonindex tumor in 31% and 32% of patients, respectively. ERG protein demonstrated independent prognostic value in predicting biochemical (P = 0.04) and clinical recurrence (P = 0.004) and appeared to have greatest prognostic value for patients with Grade Groups 4–5. In conclusion, when heterogeneity is considered, ERG protein is a robust prognostic biomarker for prostate cancer.

Evolution of prostate cancer histopathology

PURPOSE OF REVIEW

During the last 15 years several updates in the Gleason grading have been made. With the help of pertinent research results pathologists have gained a better insight into the meanings of several prostate cancer (PCa) patterns and know better how to classify them in the Gleason grade system.

RECENT FINDINGS

During the last years PCa with cribriform architecture has be given much attention. Many data have also been published about the meaning of comedonecrosis and its relationship with Gleason pattern 4 and 5. The correlationship between comedonecrosis and intraductal PCa has also been highlighted in the recent literature. Intraductal PCa is one of the most described topics at the moment with implications to treatment such as radiation therapy. We also highlight several practical issues such as the differences of grading in prostate biopsies and prostatectomies and describe the problematic of reporting a minor high-grade pattern.

SUMMARY

Many new and recent data have allowed to refine diagnosis in PCa and improve the patients's treatment. We show that comedonecrosis can be overgraded and insist on the implication with cribriform and intraducatal carcinomas. Furthermore, we describe the importance of these PCa types especially in the consideration of further treatment.

Prostate cancer pathology: What has changed in the last 5 years

Prostate cancer is the most frequent non-cutaneous malignancy in men in the United States. In the last few years, many recommendations have been made available from the 2014 International Society of Urologic Pathology consensus conference, 2016 World Health Organization blue book and 2018 8th edition of American Joint Committee on Cancer Staging System. Here, we focus on four topics which are considered relevant on the basis of their common appearance in routine practice, clinical importance and 'need to improve communication between pathology reports and clinicians': prostate cancer classification, prostate cancer grading, prostate cancer staging, and current definition of clinically significant prostate cancer. Tissue biomarkers that can predict significant disease and/or upgrading and tissue-based genomics for the purpose of diagnosis and prognosis are mentioned briefly.

The influence of the presence of intraductal carcinoma of the prostate on the grade group system's prognostic performance

BACKGROUND

Although the presence of intraductal carcinoma of the prostate (IDC-P) influences biochemical failure in radical prostatectomy patients, no data are available regarding the impact of its integration into the classification grade group system. Thus, the aim of this study was to enhance the utility of the grade group system by integrating the presence of IDC-P.

METHODS

This study was a retrospective evaluation of 1019 patients with prostate cancer who underwent radical prostatectomy between 2005 and 2013 without neoadjuvant or adjuvant therapy. The data on age, prostate-specific antigen (PSA) level at diagnosis, pathological T stage (pT), presence of Gleason pattern 5 (GP5), presence of IDC-P, and surgical margin status were analyzed to predict PSA recurrence after prostatectomy.

RESULTS

The median patient age was 67 (range, 45-80) years and the median initial PSA level was 6.8 (range, 0.4-82) ng/mL. The median follow-up period was 82 (range, 0.7-148) months. IDC-P was detected in 157 patients (15.4%). Among these patients, the increase in the positive rate of IDC-P correlated with tumor upgrading. The grade groups (GGs) were as follows: GG1 without IDC-P, 16.0% (n = 163); GG2 without IDC-P, 46.1% (n = 470); GG3 without IDC-P, 15.7% (n = 160); GG4 without IDC-P, 2.6% (n = 27); GG5 without IDC-P, 4.1% (n = 42); any GG with IDC-P, 15.4% [n = 157; GG 2 (n = 29); GG3 (n = 60); GG4 (n = 13); GG5 (n = 55)]. Any grade Group with IDC-P showed significantly worse prognosis than any other group without IDC-P (P < 0.0001). In a multivariate analysis, integration of the IDC-P into the Grade Groups, the PSA level at diagnosis, and the surgical margin status were significant prognostic predictors (P < 0.0001, < 0.0001 and < 0.0001, respectively).

CONCLUSIONS

Integrating the presence of IDC-P into the grade group system will result in more accurate predictions of patient outcome.

Grading of prostate cancer: a work in progress

Grading of prostate cancer has evolved substantially over time, not least because of major changes in diagnostic approach and concomitant shifts from late- to early-stage detection since the adoption of PSA testing from the late 1980s. After the conception of the architecture-based nine-tier Gleason grading system more than 50 years ago, several changes were made in order to increase its prognostic impact, to reduce interobserver variation and to improve concordance between prostate needle biopsy and radical prostatectomy grading. This eventually resulted in the current five-tier grading system, with a much more detailed description of the individual architectural patterns constituting the remaining three Gleason patterns (i.e. grades 3-5). Nevertheless, there is room for improvement. For instance, distinction of common grade 4 subpatterns such as ill-formed and fused glands from the grade 3 pattern is challenging, blurring the division between low-risk patients who could be eligible for deferred therapy and those who need curative therapy. The last few years have witnessed the publication of several studies on the prognostic impact of individual architectural subpatterns showing that, in particular, the cribriform pattern exceeded the prognostic impact of other grade 4 subpatterns. This review provides an overview of the changes in prostate cancer grading over time and provides a thorough description of the various Gleason subpatterns, the current evidence of their prognostic impact and areas of contention. Potential practical ways for improvements of the current grading system are also put forward.

The impact of intraductal carcinoma of the prostate on the site and timing of recurrence and cancer-specific survival

BACKGROUND

To investigate the effect of intraductal carcinoma of the prostate (IDC-P) in radical prostatectomy (RP) specimens in the context of the site of recurrence, time to recurrence, and cancer-specific survival in two academic cohorts of locally, regionally, or distantly recurrent prostate cancer.

METHODS

Our cohort included men enrolled into two academic tissue repositories from 1993 to 2011, who were treated with first-line RP who later experienced local recurrence, regional recurrence, or distant metastasis (together termed clinical recurrence, CR). RP material was reviewed to identify IDC-P and to update grading to current standards. The primary endpoint was the initial location of CR. Secondary endpoints included time to CR and cancer-specific survival. Pearson's chi-square, Welch's t-test, Mann-Whitney U test and Fisher's exact test were performed for univariate analyses. Multinomial logistic regression was used for multivariate analyses. Cancer-specific survival was analyzed with the generalized Wilcoxon test and Cox regression.

RESULTS

Eighty-five patients with CR were included in the analysis. IDC-P was present in 78.5% of patients from Center 1 and 70.0% from Center 2 (P = 0.547). IDC-P was independently associated with distant metastasis at initial CR (multivariate odds ratio = 6.27, P = 0.015). IDC-P status did not affect time to recurrence; median survival without recurrence was at 53 months for IDC-P(+) and at 50 months for IDC-P(-) (P = 0.441). Distant metastases at the initial CR event had a 36% reduction of cancer-specific survival compared to local recurrences (P = 0.007). Additionally, prostatic-bed radiotherapy (adjuvant or salvage for biochemical recurrence before distant metastasis) was associated with a 25% reduction in cancer-specific mortality compared to no radiotherapy (P = 0.023). Similar reduction in cancer-specific mortality was observed in the subgroup of patients with distant metastasis and IDC-P when treated with radiotherapy (29%, P = 0.050).

CONCLUSIONS

In our cohort, presence of IDC-P was an independent factor for distant metastasis at initial CR, but did not have a significant impact on time to CR. Furthermore, metastatic patients showed statistically reduced cancer-specific mortality when treated with radiotherapy. This reduction in cancer-specific mortality was also identified in patients with IDC-P. Future large scale validation studies should take into account the presence of IDC-P and confirm its impact on disease progression.

Precursor Lesions of Urologic Malignancies

CONTEXT

- Precursor lesions of urologic malignancies are established histopathologic entities, which are important not only to recognize for clinical purposes, but also to further investigate at the molecular level in order to gain a better understanding of the pathogenesis of these malignancies.

OBJECTIVE

- To provide a brief overview of precursor lesions to the most common malignancies that develop within the genitourinary tract with a focus on their clinical implications, histologic features, and molecular characteristics.

DATA SOURCES

- Literature review from PubMed, urologic pathology textbooks, and the 4th edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs. All photomicrographs were taken from cases seen at Weill Cornell Medicine or from the authors' personal slide collections.

CONCLUSIONS

- The clinical importance and histologic criteria are well established for the known precursor lesions of the most common malignancies throughout the genitourinary tract, but further investigation is warranted at the molecular level to better understand the pathogenesis of these lesions. Such investigation may lead to better risk stratification of patients and potentially novel treatments.

Histopathological features of intra-ductal carcinoma of prostatic and high grade prostatic intraepithelialneoplasia and correlation with PTEN and P63

BACKGROUND

The main morphologic differential diagnosis of intra-ductal carcinoma of prostate (IDC-P) is high grade prostatic intraepithelialneoplasia (HGPIN). Since IDC-P, unlike PIN, was strongly correlated with aggressive prostate cancer, differentiation of these is too necessary. So we evaluated immunohistopathological patterns and the prognostic factors of IDC-P and HGPIN, in radical prostatectomy samples.

METHODS

We evaluated 250 radical prostatectomy and detected 210 cases of prostatic adenocarcinoma without IDC-P foci, 40 cases with adenocarcinoma concomitant IDC-P, and 40 cases HGPIN; therefore, we evaluated immunohistopathological criteria in these groups. Data were analyzed using SPSS and P-value <0.05 was considered as the statistical significant level.

RESULTS

PSA level was significantly higher in IDC-P compared with non-IDC-P patients (15.7 ± 3.1 vs. 10.2 ± 4.3, P = 0.041). All pathological and morphologic features, also invasions factors were higher in IDC-P compared to non-IDC-P groups (P < 0.001). P63 was positive expressed in all IDC-P and HGPIN specimen. PTEN protein was diffusely expressed in the cytoplasm of all HGPIN but in 4 (11.1%) of IDC-P. PTEN and P63 were negative in adenocarcinoma foci.

CONCLUSION

We found that IDC-P had a unique histoclinical feature and was strongly associated with poor prognostic factors. Diagnosis and report of IDC-P should be considered in all prostate specimens. Also, we recommend PTEN IHC application for differentiated IDC-P from HGPIN in biopsies.

[Intraductal carcinoma of the prostate]

For many tumor entities, especially in breast cancer, an intraductal carcinoma is generally perceived as a precursor lesion, which precedes the emergence of invasive carcinoma. Therefore, in addition to parameters of the invasive carcinoma, histological parameters of the intraductal component have always played an important role in therapy planning of breast cancer. This is different in prostate cancer and although the term "intraductal carcinoma" has long been propagated by some authors, its routine use remains rare and inconsistent. This is certainly not only due to the far simpler therapy options of prostate cancer, in which focal and organ-preserving therapies still play a subordinate role, but also due to substantial interobserver variation and our inconsistent perception of intraductal carcinomas. This article gives a brief overview of currently available literature on this topic and explains why intraductal carcinoma of the prostate deserves our attention. In contrast to breast cancer, intraductal carcinoma of the prostate usually represents a post-invasive lesion, in which an aggressive tumor exhibits spread into pre-existing ducts; however, in rare cases, intraductal carcinoma may represent a true precursor lesion.

Molecular evidence that invasive adenocarcinoma can mimic prostatic intraepithelial neoplasia (PIN) and intraductal carcinoma through retrograde glandular colonization

Prostate cancer often manifests as morphologically distinct tumour foci and is frequently found adjacent to presumed precursor lesions such as high-grade prostatic intraepithelial neoplasia (HGPIN). While there is some evidence to suggest that these lesions can be related and exist on a pathological and morphological continuum, the precise clonal and temporal relationships between precursor lesions and invasive cancers within individual tumours remain undefined. Here, we used molecular genetic, cytogenetic, and histological analyses to delineate clonal, temporal, and spatial relationships between HGPIN and cancer lesions with distinct morphological and molecular features. First, while confirming the previous finding that a substantial fraction of HGPIN lesions associated with ERG-positive cancers share rearrangements and overexpression of ERG, we found that a significant subset of such HGPIN glands exhibit only partial positivity for ERG. This suggests that such ERG-positive HGPIN cells either rapidly invade to form adenocarcinoma or represent cancer cells that have partially invaded the ductal and acinar space in a retrograde manner. To clarify these possibilities, we used ERG expression status and TMPRSS2-ERG genomic breakpoints as markers of clonality, and PTEN deletion status to track temporal evolution of clonally related lesions. We confirmed that morphologically distinct HGPIN and nearby invasive cancer lesions are clonally related. Further, we found that a significant fraction of ERG-positive, PTEN-negative HGPIN and intraductal carcinoma (IDC-P) lesions are most likely clonally derived from adjacent PTEN-negative adenocarcinomas, indicating that such PTEN-negative HGPIN and IDC-P lesions arise from, rather than give rise to, the nearby invasive adenocarcinoma. These data suggest that invasive adenocarcinoma can morphologically mimic HGPIN through retrograde colonization of benign glands with cancer cells. Similar clonal relationships were also seen for intraductal carcinoma adjacent to invasive adenocarcinoma. These findings represent a potentially undervalued indicator of pre-existing invasive prostate cancer and have significant implications for prostate cancer diagnosis and risk stratification.

Not all gleason pattern 4 prostate cancers are created equal: A study of latent prostatic carcinomas in a cystoprostatectomy and autopsy series

BACKGROUND

The Gleason grading system represents the cornerstone of the management of prostate cancer. Gleason grade 4 (G4) is a heterogeneous set of architectural patterns, each of which may reflect a distinct prognostic value.

METHODS

We determined the prevalence of the various G4 architectural patterns and intraductal carcinoma (IDC) in latent prostate cancer in contemporary Russian (n = 220) and Japanese (n = 100) autopsy prostates and in cystoprostatectomy (CP) specimens (n = 248) collected in Italy. We studied the association of each G4 pattern with extraprostatic extension (EPE) and tumor volume to gain insight into their natural history. Presence of IDC and nine architectural features of Gleason grade 4 and 5 cancer were recorded.

RESULTS

The prevalence of Gleason score ≥ 7 PC was higher in the autopsy series (11%) compared to the CP series (6.5%, P = 0.04). The prevalence of IDC and carcinoma with a cribriform architecture was 2.2% and 3.4% in the autopsy series and 0.8% and 3.6% in the cystoprostatectomy series, respectively. In multivariable analysis, cribriform architecture was significantly associated with increased tumor volume (P < 0.001) and EPE (OR:11.48, 95%CI:2.30-57.16, P = 0.003). IDC was also significantly associated with EPE (OR:10.08, 95%CI:1.58-64.28, P = 0.014). Small fused glands had a strong negative association with EPE in the autopsy series (OR:0.06, 95%CI:0.01-0.58, P = 0.015).

DISCUSSION

Our study revealed that in latent prostate cancer both cribriform architecture and IDC are uniquely associated with poor pathological outcome features. In contrast, Gleason score 7 (3 + 4) cancers with small-fused gland pattern might possibly include some prostate cancers with a more indolent biology.

Intraductal carcinoma of the prostate: a comprehensive and updated review

Intraductal carcinoma of the prostate is characterized by prostatic carcinoma cells growing within ducts and/or acini. These tumors are usually associated with a high-grade Gleason score, large tumor volume and advanced stage. Intraductal carcinoma of the prostate is also a well-known adverse independent prognostic factor regardless of treatment. Recent studies have shown that intraductal carcinoma of the prostate is a distinctive disease entity that is different from invasive prostate carcinoma, which is generally invasive. Although the Gleason score does not consider intraductal carcinoma of the prostate, some cribriform prostate carcinomas graded as pattern 4 could be considered as intraductal carcinomas. The definition of intraductal carcinoma of the prostate is not unified, because it can occur with or without invasive prostate carcinoma. Furthermore, diagnosis of intraductal carcinoma of the prostate without invasive prostate carcinoma by needle biopsy is crucial, but is a rare event. Differential diagnosis of intraductal carcinoma of the prostate includes several pathologies. This is especially true for high-grade prostatic intraepithelial neoplasia, although its distinction is not always straightforward. The present review discusses the concept of intraductal carcinoma of the prostate, and also describes its morphological characteristics, molecular features and clinical outcome. Given the current state of knowledge, the presence of intraductal carcinoma of the prostate should be evaluated and documented correctly in both radical prostatectomy and needle biopsy, and the clinical implications should be taken into consideration during treatment and follow up.

Patient-derived xenografts reveal that intraductal carcinoma of the prostate is a prominent pathology in BRCA2 mutation carriers with prostate cancer and correlates with poor prognosis

BACKGROUND

Intraductal carcinoma of the prostate (IDC-P) is a distinct clinicopathologic entity associated with aggressive prostate cancer (PCa). PCa patients carrying a breast cancer 2, early onset (BRCA2) germline mutation exhibit highly aggressive tumours with poor prognosis.

OBJECTIVE

To investigate the presence and implications of IDC-P in men with a strong family history of PCa who either carry a BRCA2 pathogenic mutation or do not carry the mutation (BRCAX).

DESIGN, SETTING, AND PARTICIPANTS

Patient-derived xenografts (PDXs) were generated from three germline BRCA2 mutation carriers and one BRCAX patient. Specimens were examined for histologic evidence of IDC-P. Whole-genome copy number analysis (WG-CNA) was performed on IDC-P from a primary and a matched PDX specimen.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The incidence of IDC-P and association with overall survival for BRCA2 and BRCAX patients were determined using Kaplan-Meier analysis.

RESULTS AND LIMITATIONS

PDXs from BRCA2 tumours showed increased incidence of IDC-P compared with sporadic PCa (p=0.015). WG-CNA confirmed that the genetic profile of IDC-P from a matched (primary and PDX) BRCA2 tumour was similar. The incidence of IDC-P was significantly increased in BRCA2 carriers (42%, n=33, p=0.004) but not in BRCAX patients (25.8%, n=62, p=0.102) when both groups were compared with sporadic cases (9%, n=32). BRCA2 carriers and BRCAX patients with IDC-P had significantly worse overall and PCa-specific survival compared with BRCA2 carriers and BRCAX patients without IDC-P (hazard ratio [HR]: 16.9, p=0.0064 and HR: 3.57, p=0.0086, respectively).

CONCLUSIONS

PDXs revealed IDC-P in patients with germline BRCA2 mutations or BRCAX classification, identifying aggressive tumours with poor survival even when the stage and grade of cancer at diagnosis were similar. Further studies of the prognostic significance of IDC-P in sporadic PCa are warranted.

PATIENT SUMMARY

Intraductal carcinoma of the prostate is common in patients with familial prostate cancer and is associated with poor outcomes. This finding affects genetic counselling and identifies patients in whom earlier multimodality treatment may be required.

Computer-assisted three-dimensional analysis of multifocal/multicentric prostate cancer

In order to study multiple contiguous prostate cancer lesions, we constructed computer-assisted, three-dimensional models of multifocal prostate cancer specimens obtained by radical prostatectomy. We then examined the genetic heterogeneity among the specimens by DNA microarray analysis. Cancer foci with high Gleason patterns were found to occur de novo, whereas those with low Gleason patterns occurred contiguously with cancers of low Gleason patterns. Three-dimensional analysis showed that distinct, noncontiguous cancerous foci were genetically independent and multicentric. In contrast some contiguous multifocal lesions had the same genetic origin.

Prognostic value of intraductal carcinoma of the prostate in radical prostatectomy specimens

BACKGROUND

Intraductal carcinoma of the prostate (IDC-P) is an adverse prognostic factor for radical prostatectomy (RP). The endpoint in most IDC-P studies is increased prostate-specific antigen (PSA) levels. The aim of this study was to evaluate whether IDC-P in RP specimens is an adverse prognostic factor for progression-free survival (PFS) and cancer-specific survival (CSS).

METHODS

We retrospectively evaluated 206 high-risk prostate cancer patients treated with RP and analyzed data on age, serum PSA level at diagnosis, biopsy Gleason score (bGS), surgical margin (SM), clinical T stage (cT), extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node metastasis (LN), and neoadjuvant therapy.

RESULTS

An IDC-P component was found in 104 cases. Forty-four patients experienced clinical failure, and 20 patients died of the disease. Patients with IDC-P showed a higher bGS and stage (including cT, EPE, SVI, and LN) than those without IDC-P. In univariate analysis, IDC-P, PSA level, bGS, SM, cT, SVI, LN, and EPE (P < 0.0001) were significantly associated with PFS. IDC-P (P = 0.0004), PSA level (P < 0.0001), SM (P = 0.0013), cT (P = 0.0019), SVI (P = 0.0012), and LN (P = 0.0002) were significantly associated with CSS. In multivariate analysis, IDC-P (P = 0.0038), and cT (P = 0.0001) were significantly associated with PFS. IDC-P (P = 0.0238) and PSA level (P = 0.0112) were significantly associated with CSS.

CONCLUSIONS

IDC-P in RP specimens was an independent risk factor for PFS and CSS and could predict clinical outcomes.

Clinicopathological analysis of intraductal proliferative lesions of prostate: intraductal carcinoma of prostate, high-grade prostatic intraepithelial neoplasia, and atypical cribriform lesion

Intraductal carcinoma of the prostate (IDC-P) and high-grade prostatic intraepithelial neoplasia (HGPIN) are two distinct intraductal lesions; the former is usually associated with invasive carcinoma and has an aggressive course while the latter is considered a precancerous lesion. In addition, there are morphologically lesions not well characterized that fall between IDC-P and HGPIN, consequently termed "atypical cribriform lesions (ACLs)." Using whole mount radical prostatectomy specimens, we evaluated the relationship between these intraductal proliferative lesions and clinicopathological parameters. In this study, ACLs were characterized as a loose cribriform intraductal proliferation with greater architectural complexity when compared to HGPIN, but lacking significant nuclear pleomorphism and/or comedonecrosis. Of 901 radical prostatectomies (2006-2012), IDC-P, ACL, and HGPIN were recorded in 155, 22, 436 cases, respectively. Patients with IDC-P showed more aggressive pathologic features when compared to HGPIN. Invasive cancers in patients with ACL had higher Gleason score (P=.00016), larger tumor volume (P=.025), and more advanced pT stage (P=.023) than those with HGPIN. Cases with ACL showed a higher risk of biochemical recurrence than those with HGPIN and a lower risk than those with IDC-P based on log-rank tests (P=.0045 and P=.0069, respectively). In multivariate analysis, the presence of HGPIN was identified as an independent predictor for infrequent biochemical recurrence (P=.0058). We confirmed IDC-P as a marker of adverse pathologic features and clinical aggressiveness. Our results suggest that ACL should be distinguished from HGPIN and these lesions mandate active clinical surveillance.

Intraductal carcinoma of prostate: a comprehensive and concise review

Intraductal carcinoma of the prostate (IDC-P) is defined as a proliferation of prostate adenocarcinoma cells distending and spanning the lumen of pre-existing benign prostatic ducts and acini, with at least focal preservation of basal cells. Studies demonstrate that IDC-P is strongly associated with high-grade (Gleason grades 4/5), large-volume invasive prostate cancers. In addition, recent genetic studies indicate that IDC-P represents intraductal spread of invasive carcinoma, rather than a precursor lesion. Some of the architectural patterns in IDC-P exhibit architectural overlap with one of the main differential diagnoses, high-grade prostatic intraepithelial neoplasia (HGPIN). In these instances, additional diagnostic criteria for IDC-P, including marked nuclear pleomorphism, non-focal comedonecrosis (>1 duct showing comedonecrosis), markedly distended normal ducts/acini, positive nuclear staining for ERG, and cytoplasmic loss of PTEN by immunohistochemistry, can help make the distinction. This distinction between IDC-P and HGPIN is of critical importance because IDC-P has an almost constant association with invasive carcinoma and has negative clinical implications, including shorter relapse-free survival, early biochemical relapse, and metastatic failure rate after radiotherapy. Therefore, IDC-P should be reported in prostate biopsies and radical prostatectomies, regardless of the presence of an invasive component. This article will review the history, diagnostic criteria, molecular genetics, and clinical significance of IDC-P.

[Benign mimickers of the prostate cancer. Diagnostic challenges]

The diagnosis of prostate cancer (PCa), especially limited adenocarcinoma on needle biopsy, is often challenging. Before making diagnosis of PCa, it is prudent for the pathologist to consider different benign patterns that may lead to a false positive interpretation. Histoanatomic structures such as seminal vesicles, Cowper's glands and paraganglia along with hyperplasia, atrophy with its different patterns and adenosis may generate difficulties in differential diagnosis. Furthermore, inflammatory processes and post-treatment changes may cause problems. The above entities can in some instances simulate low-grade and less commonly high grade PCa. Knowledge of these patterns and application of appropriate immunohistochemistry will lead the pathologist to a correct diagnosis.

Incidence and clinicopathological characteristics of intraductal carcinoma detected in prostate biopsies: a prospective cohort study

AIMS

Intraductal carcinoma of the prostate (IDC-P) is a distinct clinicopathological entity and is associated with aggressive, high-grade and high-volume prostate carcinoma (PCa). The incidence, clinicopathological characteristics and prognostic significance of IDC-P have not been reported in prostate biopsies (PBx) that surgical pathologists encounter in their daily practice.

METHODS AND RESULTS

In 1176 prospectively collected PBx, 33 IDC-P cases were identified (2.8%). The mean age of patients with IDC-P was 65 (range 46-79) years and mean serum prostate-specific antigen was 16.2 (range 0.4-105.6) ng/ml. Three (0.26%) IDC-P cases did not have a concomitant invasive PCa. Of 30 cases with concomitant invasive PCa, Gleason score was 7 in 16 (53.3%), 8 in four (13.3%) and 9 in 10 (33.3%) cases. The mean number of biopsy cores involved by PCa was 7.2 (range 1-14). Nine patients were treated with radical prostatectomy. Seminal vesicle invasion was found in four of nine (44%) cases, significantly higher than the risk of 12% predicted by Partin Tables (P = 0.016).

CONCLUSIONS

This is the first prospective study that has investigated the incidence and prognostic significance of IDC-P diagnosed in PBx encountered in daily practice. It is critical for surgical pathologists to diagnose and report IDC-P in PBx.