Does prostatic ductal adenocarcinoma exist?

Genomic analysis of aggressive ductal adenocarcinoma of the prostate

BACKGROUND

Genomic profile analysis using next-generation sequencing can potentially elucidate the pathogenesis of rare cancers. Ductal adenocarcinoma, a rare subtype of prostate cancer, has an aggressive nature. This is the first study to analyze the genomic profile of ductal adenocarcinoma in an Asian population.

METHODS

We identified 12 patients newly diagnosed with ductal adenocarcinoma of the prostate at two hospitals, and nine patients (75.0%) had the pure type. Genomic assessment was performed using either the PleSSision testing platform or FoundationOne CDx.

RESULTS

At least one genomic alteration occurred in 11 patients (91.7%), and the most frequently mutated gene was tumor suppressor protein p53 (TP53), which was found in six cases (50.0%). Alterations characteristic of this cohort were found in four cases (33.3%) of retinoblastoma transcriptional corepressor 1 (RB1), which was only observed in the pure type. Compared to previous study results, the frequency of genetic alterations in the phosphoinositide 3-kinase (PI3K) pathway (n = 3; 25.0%) and Wnt-β-catenin pathway (n = 5; 41.7%) was comparable, but no alterations in the DNA damage repair (DDR) pathway were observed. None of the patients presented high tumor mutation burden or microsatellite instability.

CONCLUSIONS

We found that the Asian cohort with ductal adenocarcinoma had actionable alterations, and a high frequency of alterations in TP53 and RB1 reflected the aggressive nature of the tumor. Genetic analysis using next-generation sequencing is expected to help elucidate the pathogenesis of ductal adenocarcinoma.

Magnetic resonance imaging findings of pure prostatic ductal adenocarcinomas: a case series

PURPOSE

This study aimed to investigate the characteristics of magnetic resonance imaging (MRI) findings in pure prostatic ductal adenocarcinoma.

METHODS

From January 2009 to February 2020, seven patients who were diagnosed with pure prostatic ductal adenocarcinoma and had a referable preoperative MRI scan were included in the study. We evaluated the following MRI findings for each tumor: size, location, presence of multi-cystic component, and apparent diffusion coefficient (ADC) value.

RESULTS

The median maximum diameter of the tumors was 22 mm (range 19-70 mm). Regarding transverse distribution, five tumors were located in the periurethral area and two were located peripherally apart from the urethra. Two of the seven tumors had cystic components. The median ADC value of the tumors was 0.754 × 10^-3 mm²/s (range 0.570-0.963 × 10^-3 mm²/s). Based on the transverse distribution and components of the tumors on MRI, ductal adenocarcinomas were classified into three types: type I as a non-cystic tumor located peripherally apart from the urethra (29%, two cases); type II as a non-cystic tumor located in the periurethral area (43%, three cases); and type III as a tumor with a multi-cystic component (29%, two cases).

CONCLUSION

The non-cystic mass with periurethral distribution (type II) and multi-cystic mass (type III) may be characteristic features that differentiate pure ductal adenocarcinoma from ordinary acinar adenocarcinoma on MRI.

Ductal and acinar components of mixed prostatic adenocarcinoma frequently have a common clonal origin

BACKGROUND

Ductal adenocarcinoma (DA) is an aggressive subtype of prostate cancer. It is most commonly seen in mixed tumors together with conventional acinar adenocarcinoma (AA). The genetic profile of DA and its clonal origin is not fully characterized.

OBJECTIVE

To investigate whether DA represents a distinct genetic subtype and to investigate the somatic relationship between the ductal and acinar components of mixed cancers.

DESIGN, SETTING, AND PARTICIPANTS

In 17 radical prostatectomy specimens ductal and acinar tumor components from the same tumor foci were dissected. DNA was extracted and genomic sequencing performed. After exclusion of two cases with low cell yield, 15 paired samples remained for analysis.

RESULTS

In 12 of 15 cases a common somatic denominator was identified, while three cases had clonally separate components. In DA, TMPRSS2-ERG gene fusions were detected in 47% (7/15), clonal FOXA1 alterations in 33% (5/15) and SPOP alterations in 27% (4/15) of cases. In one case KIAA1549-BRAF fusion was identified. Genome doubling events, resulting in an increased ploidy, were identified in the DA in 53% (8/15) of cases, but not seen in any AA. PTEN and CTNNB1 alterations were enriched in DA (6/15) but not seen in any AA. No cancers showed microsatellite instability or high tumor mutation burden.

CONCLUSIONS

Ductal and acinar prostate adenocarcinoma components of mixed tumors most often share the same origin and are clonally related. DA components in mixed tumor often exhibit genome doubling events resulting in aneuploidy, consistent with the aggressive nature of high grade prostate cancer.

Defining Diagnostic Criteria for Prostatic Ductal Adenocarcinoma at Multiparametric MRI

Background Prostatic ductal adenocarcinoma (DAC) is an aggressive histologic variant of prostate cancer that often warrants multimodal therapy and poses a significant diagnostic challenge clinically and at imaging. Purpose To develop multiparametric MRI criteria to define DAC and to assess their diagnostic performance in differentiating DAC from prostatic acinar adenocarcinoma (PAC). Materials and Methods Men with histologically proven DAC who had multiparametric MRI before radical prostatectomy were retrospectively identified from January 2011 through November 2018. MRI features were predefined using a subset of nine DACs and then compared for men with peripheral-zone DACs 1 cm or greater in size and men with matched biopsy-confirmed International Society of Urological Pathology grade group 4-5 PAC, by four independent radiologists blinded to the pathologic diagnosis. Diagnostic performance was determined by consensus read. Patient and tumor characteristics were compared by using the Fisher test, t-tests, and Mann-Whitney U test. Agreement (Cohen κ) and sensitivity analyses were also performed. Results There were 59 men with DAC (median age, 63 years [interquartile range, 56, 67 years]) and 59 men with PAC (median age, 64 years [interquartile range, 59, 69 years]). Predefined MRI features, including intermediate T2 signal, well-defined margin, lobulation, and hypointense rim, were detected in a higher proportion of DACs than PACs (76% [45 of 59] vs 5% [three of 59]; P < .001). On consensus reading, the presence of three or more features demonstrated 76% sensitivity, 94% specificity, 94% positive predictive value [PPV], and 80% negative predictive value [NPV] for all DACs and 100% sensitivity, 95% specificity, 81% PPV, and 100% NPV for pure DACs. The DACs and PACs showed no difference in contrast enhancement (100% vs 100%; P >.99, median T2 signal intensity (254 vs 230; P = .99), or apparent diffusion coefficient (median, 677 10^-6 mm²/sec vs 685 10^-6 mm²/sec; P = .73). Conclusion The presence of intermediate T2 signal, well-defined margin, lobulation, and/or hypointense rim, together with restricted diffusion and contrast enhancement at multiparametric MRI of the prostate, suggests prostatic ductal adenocarcinoma rather than prostatic acinar adenocarcinoma. © RSNA, 2022 Online supplemental material is available for this article.

Prostatic Ductal Adenocarcinoma Controlled for Tumor Grade, Stage, and Margin Status Does Not Independently Influence the Likelihood of Biochemical Recurrence in Localized Prostate Cancer After Radical Prostatectomy

CONTEXT.—

Prostatic ductal adenocarcinoma (PDA) has historically been considered to be an aggressive subtype of prostate cancer.

OBJECTIVE.—

To investigate if PDA is independently associated with worse biochemical recurrence (BCR)-free survival after radical prostatectomy.

DESIGN.—

A review of 1584 radical prostatectomies was performed to grade, stage, and assess margin status in each tumor nodule. Radical prostatectomies with localized PDA (ie, those lacking metastasis) in the tumor nodule with the highest grade and stage and worst margin status were matched with prostatic acinar adenocarcinoma according to grade, stage, and margin status. The effect of PDA on BCR was assessed by multivariable Cox regression and Kaplan-Meier analyses.

RESULTS.—

Prostatic ductal adenocarcinoma was present in 171 cases. We excluded 24 cases because of lymph node metastasis (n = 13), PDA not in the highest-grade tumor nodule (n = 9), and positive surgical margin in a lower-grade tumor nodule (n = 2). The remaining 147 cases included 26 Grade Group (GG) 2, 44 GG3, 6 GG4, and 71 GG5 cancers. Seventy-six cases had extraprostatic extension, 33 had seminal vesicle invasion, and 65 had positive margins. Follow-up was available for 113 PDA and 109 prostatic acinar adenocarcinoma cases. Prostate-specific antigen density (odds ratio, 3.7; P = .001), cancer grade (odds ratio, 3.3-4.3; P = .02), positive surgical margin (odds ratio, 1.7; P = .02), and tumor volume (odds ratio, 1.3; P = .02) were associated with BCR in multivariable analysis. Prostatic ductal adenocarcinoma, its percentage, intraductal carcinoma, and cribriform Gleason pattern 4 were not significant independent predictors of BCR.

CONCLUSIONS.—

Advanced locoregional stage, higher tumor grade, and positive surgical margin status rather than the mere presence of PDA are more predictive of worse BCR-free survival outcomes following radical prostatectomy in men with a component of PDA.

Optimizing the diagnosis and management of ductal prostate cancer

Ductal adenocarcinoma (DAC) is the most common variant histological subtype of prostate carcinoma and has an aggressive clinical course. DAC is usually characterized and treated as high-risk prostatic acinar adenocarcinoma (PAC). However, DAC has a different biology to that of acinar disease, which often poses a challenge for both diagnosis and management. DAC can be difficult to identify using conventional diagnostic modalities such as serum PSA levels and multiparametric MRI, and the optimal management for localized DAC is unknown owing to the rarity of the disease. Following definitive therapy for localized disease with radical prostatectomy or radiotherapy, the majority of DACs recur with visceral metastases at low PSA levels. Various systemic therapies that have been shown to be effective in high-risk PAC have limited use in treating DAC. Although current understanding of the biology of DAC is limited, genomic analyses have provided insights into the pathology behind its aggressive behaviour and potential future therapeutic targets.

Comparison of Immunohistochemistry Expression of CK7, HMWK and PSA in High-Grade Prostatic Adenocarcinoma and Bladder Transitional Cell Carcinoma

Background & Objective:

Prostate adenocarcinoma is the most common malignancy in males, and the urothelial bladder carcinoma is also prevalent. The histological characteristic of these two tumors is very similar in high-grade cases, and their differentiation is difficult. This study was performed to compare the immunohistochemistry panel of high-grade prostate adenocarcinomas and high-grade urothelial bladder carcinomas.

Methods:

In this cross-sectional study, 36 cases of prostate adenocarcinoma and 36 urothelial bladder carcinoma samples were collected from the pathology department of Shahid Beheshti Hospital in Hamedan. For each sample, expression of Cytokeratin 7, high-molecular-weight cytokeratin and Prostate-specific antigen markers was evaluated by immunohistochemistry. Comparison of expression of these markers in high-grade bladder tumors and prostate tumors was made by SPSS 25 using Chi-square test.

Results:

In this study, the Cytokeratin 7 positivity was seen in 88.9% of bladder cancer versus 27.8% of prostate cancer samples. High-molecular-weight cytokeratin positive immunoreactivity was noted in 55.6% of bladder cancer and 5.6% of prostate cancer samples. Prostate-specific antigen marker showed positive results in 94.4% of prostate cancer samples, but no positivity was evident in those of bladder cancer.

Conclusion:

A panel of immunohistochemical stains can be used to differentiate high-grade prostate adenocarcinoma from urothelial bladder carcinoma in those cases which are challenging to diagnose.

The Role of Radiotherapy Among Patients With Prostate Ductal Adenocarcinoma

INTRODUCTION

The aim of this study was to perform a Surveillance, Epidemiology, and End Results (SEER) analysis on the effect of radiotherapy (RT) on survival among patients with prostate ductal adenocarcinoma (DA), a rare variant of prostate cancer.

PATIENTS AND METHODS

Cases of T1 to 4 N0 M0 prostate DA diagnosed between 2004 and 2013 were extracted from SEER. The association between categorical variables and radiation therapy was assessed for statistical significance using the χ² test or Fisher exact test. Difference in continuous variables across the RT groups was assessed for statistical significance using the 2-sample t test or non-parametric test. The distribution of overall survival (OS) and disease-specific survival (DSS) between the RT groups was assessed using the Kaplan-Meier method and the log rank test and after propensity matching. The association between hazards of death (HR) and covariates was examined using Cox proportional hazards model. A 2-sided P-value of .05 was used to determine statistical significance.

RESULTS

A total of 205 patients met inclusion criteria. On univariate analysis, RT was associated with significant improvement in OS and DSS. On multivariate Cox regression, RT significantly decreased risk of death for both OS and DSS (HR, 0.516; 95% confidence interval [CI], 0.273-0.978 and HR, 0.232; 95% CI, 0.082-0.658, respectively). After propensity score matching, RT demonstrated a persistent improvement in both OS and DSS.

CONCLUSIONS

RT decreased risk of death for both OS and DSS in patients with node-negative, nonmetastatic prostate DA on multivariable analysis. RT was also associated with improved OS and DSS after propensity matching.

PIN-like (Ductal) Adenocarcinoma of the Prostate

Prostatic intraepithelial neoplasia like (PIN-like ductal) carcinoma are rare tumors characterized by crowded, often cystically dilated glands architecturally resembling high-grade prostatic intraepithelial neoplasia, lined by malignant pseudostratified columnar epithelium. The largest prior series studied 9 radical prostatectomies (RPs) and suggested a behavior similar to Gleason score 6. We sought to investigate this rare tumor within a larger series. PIN-like carcinoma cases were identified from in-house and consultation files from 2008 to 2017. A total of 190 total cases were identified (in-house cases n=8, 4.2%, consult cases n=182, 95.8%); the diagnosis of PIN-like carcinoma was made on needle biopsy (n=181), transurethral resection (n=5) and RP (n=4). The average age was 70 years. The average number of cores with involvement by PIN-like carcinoma was 2 (1 to 12). The average maximum percentage by a PIN-like carcinoma component of any core was 43.5% (5% to 90%). In 58/181 (32.0%) biopsy cases, due to selective parts having been submitted for consultation, it was unknown whether there was an association with acinar carcinoma. A total of 72 cases showed exclusively PIN-like carcinoma. Highest grade groups (GGs) on biopsies with known acinar or papillary/cribriform ductal carcinomas were GG1 (n=23, 45.1%), GG2 (n=14, 27.5%), GG3 (n=9, 17.6%), GG4 (n=4, 7.8%), and GG5 (n=1, 2.0%). Of 44 cases where the patient would be considered eligible for active surveillance, 18 (41.0%) underwent RP. RP slides were available in 16 cases; 3 (18.8%) cases diagnosed on biopsy did not show PIN-like carcinoma on review of RP slides. PIN-like carcinoma was present without an associated acinar tumor in 3 (23.1%) RPs; 2 showing tumors with large, cystic dilated glands extending into periprostatic tissue. In 7/13 cases (53.8%), the acinar component was the dominant tumor and the PIN-like carcinoma component was small (<1 cm). The overall grade at RP was GG1 (5/13, 38.5%) and GG2 (8/13, 61.5%). In all cases with an acinar component, the acinar tumor was anatomically distinct from the PIN-like carcinoma tumor. The GGs of the separate acinar tumors were GG1 (6/10) and GG2 (4/10) with percent pattern 4 ≤5% in all 4 cases. No cases were associated with metastases to lymph nodes or seminal vesicle invasion. Extraprostatic extension was present in 6/13 (46.1%) cases, from the acinar component in 1 (7.7%) case and the PIN-like carcinoma component in 5 (83.3%) cases. In all 5 cases, there was a peculiar morphology of thin papillary projections into cystic dilated PIN-like carcinoma glands. Immunohistochemical expression of ERG was positive in 1/11 (9.1%) case. 1/11 (9.1%) case showed heterogeneous loss of PTEN. Overall, PIN-like carcinoma tumors are limited in size, not advanced in stage, not associated with high-grade cancer on RP, and show low rates of Gleason pattern 4 and TMPS-ERG rearrangement. Our study supports grading classic PIN-like carcinoma as Gleason pattern 3; at the current time we recommend grading thin papillary projections of PIN-like carcinoma as pattern 4. Longer term studies will be needed to determine the clinical significance of thin papillary projections in PIN-like carcinoma.

Large-Gland Proliferations of the Prostate

Large-gland proliferations of the prostate have gained considerable attention in the past decade. The differential diagnosis is quite broad but can be refined using histologic criteria and, sometimes, immunostains. Pathologists have come to realize that cribriform and intraductal as well as ductal carcinomas are particularly aggressive patterns, and should name them in diagnostic reporting when present.

Secondary Colonic Adenocarcinoma of the Prostate Histologically Mimicking Prostatic Ductal Adenocarcinoma

Purpose

To study the clinical presentation and pathological features of secondary colonic adenocarcinoma of the prostate.

Materials and methods

Six cases of colonic adenocarcinoma extending into the prostate were retrieved from the surgical pathology and autopsy files of the period 1985-1999. Immunostaining for prostatic acid phosphatase (PAP), prostate specific antigen (PSA), cytokeratin 7 (CK7), cytokeratin 20 (CK20) and carcinoembryonic antigen (CEA) was carried out in all cases. Clinical charts were also reviewed.

Results

Secondary colonic carcinoma spread into the prostatic stroma and along the prostatic ducts. In all four surgical cases, patients with a known history of rectal carcinoma presented with symptoms of urinary obstruction after 12 to 36 months of being free of recurrent or metastatic disease. In three surgical cases the secondary carcinoma involved the prostatic urethra in a form mimicking endometriod carcinoma, which led to an incorrect diagnosis of prostatic endometrioid carcinoma in one case. The tumor cells were immunoreactive to CK20 and CEA and not reactive to CK7, PAP and PSA.

Conclusions

Colonic carcinoma involving the prostate may mimic prostatic duct carcinoma due to the ductal and urethral involvement. Using a panel of immunostaining and clinical history is helpful in the differential diagnosis.

Differential Diagnosis of Intraductal Lesions of the Prostate

The category of intraductal lesions of the prostate includes a range of primary prostatic and nonprostatic processes with wide variation in prognosis and recommended follow-up. Studies have shown that pathologists are uncomfortable with the diagnosis of these lesions and that the diagnostic reproducibility is low in this category. Despite the diagnostic difficulty, their accurate and reproducible diagnosis is critical for patient management. This review aims to highlight the diagnostic criteria, prognosis, and treatment implications of common intraductal lesions of the prostate. It focuses on the recognition of intraductal carcinoma of the prostate (IDC-P) in prostate needle biopsies and how to distinguish it from its common mimickers, including high-grade prostatic intraepithelial neoplasia, invasive cribriform prostatic adenocarcinoma, urothelial carcinoma extending into prostatic ducts, and prostatic ductal adenocarcinoma. IDC-P is independently associated with higher risk disease, and its identification in a needle biopsy, even in the absence of invasive carcinoma, should compel definitive treatment. Conversely, high-grade prostatic intraepithelial neoplasia has a much better prognosis and in limited quantities does not even warrant a repeat biopsy. IDC-P must be distinguished from urothelial carcinoma involving prostatic ducts, as recommended treatment varies markedly. Ductal adenocarcinoma may confuse the pathologist and clinician by overlapping terminology, and morphology may also mimic IDC-P on occasion. The use of ancillary testing with immunohistochemistry and molecular markers has also been reviewed.

The update of prostatic ductal adenocarcinoma

Since initially described in 1967, prostatic ductal adenocarcinoma (PDA) has engendered a series of controversies on its origin, histological features, and biological behavior. Owing to the improvement of molecular biological technique, there are some updated findings on the characteristics of PDA. In the current review, we will mainly analyze its origin, clinical manifestations, morphological features, differential diagnosis, immunophenotype and molecular genetics, with the purpose of enhancing recognition of this tumor and making a correct diagnosis and treatment choice.

Prostatic ductal adenocarcinoma: An aggressive variant that is underdiagnosed and undersampled on transrectal ultrasound (TRUS)-guided needle biopsy

INTRODUCTION

We sought to determine if prostatic ductal adenocarcinoma is undersampled and/or underdiagnosed at transrectal ultrasound (TRUS)-guided biopsy.

METHODS

With institutional review board approval, we searched our pathology database between 2008 and 2014 for patients with a diagnosis of ≥10% ductal adenocarcinoma on radical prostatectomy and available TRUS-guided needle biopsy specimens. Three blinded genitourinary pathologists independently examined the biopsy slides. The presence or absence of ductal adenocarcinoma was determined. Diagnostic accuracy was calculated using consensus diagnosis as the reference standard. Inter-observer agreement was assessed using Cohen's kappa coefficient.

RESULTS

Based on consensus review, 66.7% (12/18) biopsy specimens demonstrated ductal adenocarcinoma and 33.3% (6/18) demonstrated conventional acinar prostatic adenocarcinoma. The sensitivity/specificity for each reader (R) was: 83/100% (R1), 100/83% (R2) and 58/83% (R3) and the inter-observer agreement was only fair (K=0.32). Only two of the original needle-biopsy reports correctly identified ductal adenocarcinoma (sensitivity = 17%). The main limitations of the study are the relatively small sample size and the potential for selection bias since we could only examine patients who underwent radical prostatectomy.

CONCLUSIONS

Prostatic ductal adenocarcinoma may be undersampled at TRUS-guided biopsy and in this study was under-reported in routine clinical practice. This highlights the importance of increased awareness of ductal adeoncarcinoma and the need for clear diagnostic criteria. These findings have significant clinical impact especially when determining candidacy for active surveillance protocols.

Metastatic Prostatic Ductal Adenocarcinoma Successfully Treated with Docetaxel Chemotherapy: A Case Report

A 68-year-old man presented with gross hematuria. A papillary urethral tumor adjacent to the verumontanum was found by cystourethroscopy. Serum prostate-specific antigen (PSA) was 3.246 ng/ml. A transurethral biopsy specimen was most suggestive of a primary urothelial carcinoma of the prostate, for which a radical cystoprostatectomy was performed. The final pathology was prostatic ductal adenocarcinoma with very focal acinar features (Gleason score 5 %plus; 4 = 9, pT3bN0M0). Local recurrence and pelvic bone metastases developed 17 months later, and his PSA rose to 10.806 ng/ml. He was treated with combined androgen blockade and radiation. Two years later, the lesion showed progressive growth. Treatment followed with docetaxel (70 mg/m(2) every 3 weeks) and prednisolone 5 mg twice daily. After 10 cycles of chemotherapy, all lesions disappeared and PSA decreased to <0.005 ng/ml. Three years after chemotherapy, he maintains a complete response without any additional treatments. Docetaxel chemotherapy can be an effective treatment for patients with recurrent prostatic ductal adenocarcinoma.

Ductal adenocarcinoma of the prostate: a Hong Kong case series

OBJECTIVES

To review and report our local experience in the management of ductal adenocarcinoma of the prostate.

METHODS

Retrospective review of patients diagnosed with ductal adenocarcinoma of the prostate in two regional urological centres in Hong Kong during 1995-2009. Clinical information, treatment and outcomes were retrieved for further analysis.

RESULTS

We identified 19 Chinese patients diagnosed with ductal adenocarcinoma of the prostate. Majority of our patients presented with retention of urine and haematuria. At presentation, seven patients were already at an advanced stage with evidence of rectal invasion or distant metastasis. The overall treatment outcome was poor with high failure rate after either local or systemic hormonal therapy.

CONCLUSION

We observed a predilection of this tumour to be locally aggressive, and hence a relatively high incidence of intra-luminal growth and rectal invasion. We observed a high failure rate after either radical prostatectomy or hormonal therapy.

Immunohistochemical profile of ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate (DAC) is considered to be an aggressive subtype of prostate cancer with greater risk of progression than acinar adenocarcinoma (AC). It has been debated whether DAC is a distinct subtype or a morphological variant of AC. Our aim was to examine the protein expression of DAC and to compare the results with AC. A tissue microarray was constructed from 60 DAC and 46 AC matched by Gleason score. The slides were stained for 28 immunomarkers (estrogen, progesterone and androgen receptor, prolactin, PSA, prostein, PSMA, PSAP, CDX2, lysozyme, villin, monoclonal CEA, CK7, CK20, HMWCK, p63, p504s, c-myc, EGFR, Ki-67, p16, p21, p27, p53, PTEN, ERG, PAX-2, and PAX-8). HMWCK was positive in 8.5 % of DAC, but negative in all cases of AC (p = 0.045). p16 was positive in 53.3 % of DAC and in 26.1 % of AC (p = 0.005). p53 was positive in 42.4 % of DAC and 26.7 % of AC (p = 0.031). A distinct patchy positivity of CK20 was seen in 23.7 % of DAC, and this pattern was also seen in 9.1 % of AC (p = 0.047). Villin was positive in 3.4 % of DAC while expression was negative in AC. Ki-67 labeling index was significantly higher in DAC than in AC (mean 9.2 % [95 % CI 6.4-12.0] and 2.6 % [1.9-3.4], p < 0.001). While there is some overlap in the immunohistochemical expression of DAC and AC, the differences between these two morphotypes of prostatic carcinoma are consistent with DAC having a more aggressive phenotype than AC.

Abiraterone acetate and castration resistant ductal adenocarcinoma of the prostate

Ductal adenocarcinoma of the prostate is a rare histological variant that only represents <1% of prostate tumors. This histological variant has several important clinical implications with respect to their evolution, clinical prognosis, and treatment. We report the case of a 64-year-old patient with ductal adenocarcinoma of the prostate, which progresses to castration-resistant prostate cancer, that was treated with abiraterone acetate with good clinical response, to our knowledge, the first case of ductal adenocarcinoma of the prostate in treatment with abiraterone acetate.

Diagnostic criteria for ductal adenocarcinoma of the prostate: interobserver variability among 20 expert uropathologists

AIMS

Ductal adenocarcinoma of the prostate (DAC) is clinically important, because its behaviour may differ from that of acinar adenocarcinoma. Our aims were to investigate the interobserver variability of this diagnosis among experts in uropathology and to define diagnostic criteria.

METHODS AND RESULTS

Photomicrographs of 21 carcinomas with ductal features were distributed among 20 genitourinary pathologists from eight countries. DAC was diagnosed by 18 observers (mean 13.2 cases, range 6-19). In 11 (52%) cases, a 2/3 consensus was reached for a diagnosis of DAC, and in five (24%) there was consensus against. In DAC, the respondents reported papillary architecture (86%), stratification of nuclei (82%), high-grade nuclear features (54%), tall columnar epithelium (53%), elongated nuclei (52%), cribriform architecture (40%), and necrosis (7%). The most important diagnostic feature reported for DAC was papillary architecture (59%), whereas nuclear and cellular features were considered to be most important in only 2-11% of cases. The most common differential diagnoses were intraductal prostate cancer (52%), high-grade PIN (37%), and acinar adenocarcinoma (17%). The most common reason for not diagnosing DAC was lack of typical architecture (33%).

CONCLUSIONS

Papillary architecture was the most useful diagnostic feature of DAC, and nuclear and cellular features were considered to be less important.

Histopathological features of ductal adenocarcinoma of the prostate in 1,051 radical prostatectomy specimens

Ductal adenocarcinoma (DAC) of the prostate is thought to have worse prognosis than prostatic acinar carcinoma (PAC). We aimed to evaluate the prognostic significance of histopathological patterns of DAC. A series of 1,051 radical prostatectomy specimens from Karolinska University Hospital 1998-2005 was reviewed. A ductal component was classified as classical DAC (DACC) if it had columnar, pseudostratified epithelium, elongated nuclei, and papillary, glandular, or cribriform architecture; borderline DAC (DACB) if it lacked elongated nuclei or classical architecture; and prostatic adenocarcinoma with ductal features (PCDF) if stratified high-grade nuclei were found. DACC, DACB, and PCDF were seen in 2.6, 4.0, and 1.6 % of the cases. DAC was usually mixed with PAC and constituted 10-100 % (mean 40 %) of the main tumor. Location was periurethral, peripheral, or both in 69.8, 3.5, and 26.7 %. Necrosis was seen in 31.3 %, stromal invasion of DAC in 52.3 %, and intraductal spread in 91.9 %. In DACC/DACB and PAC, extraprostatic extension was seen in 66.7 and 42.4 % (p < 0.001) and seminal vesicle invasion in 13.0 and 5.0 % (p = 0.0045). DACC, DACB, and PCDF had a hazard ratio for biochemical recurrence of 1.5 (0.7-2.8), 1.4 (0.8-2.6) and 1.2 (0.5-2.7). When PCDF was excluded from DAC, hazard ratio was 1.4 (95 % CI 0.9-2.3, p = 0.12). Location, % DAC, necrosis, stromal invasion, or Gleason score were not predictive of recurrence. This suggests that DACC and DACB are more aggressive than average PAC, while cancers with acinar architecture and pseudostratified high-grade nuclei should not be included in DAC.

[Ductal adenocarcinoma of the prostate: a report of 7 cases]

Ductal adenocarcinoma of the prostate is a rare subtype of prostatic adenocarcinoma, defined by morphological criteria as one that has papillary or cribriform architecture composed of high columnar cells with pseudostratified nuclei. We clinically evaluated 7 cases of ductal adenocarcinoma of the prostate in our hospital. The median age was 69 years old and median initial serum PSA level was 22.8 ng/ml. Two cases presented with dysuria, two with macrohematuria and one with abnormality on chest radiograph. Five cases were diagnosed on prostate biopsy, one on TUR-P and one on radical prostatectomy. Two had pure ductal adenocarcinoma and five had mixed ductal adenocarcinoma. Four had metastatic disease, and were treated by hormonal therapy. Among three with non-metastatic disease, two underwent radical prostatectomy with adjuvant radiotherapy and one underwent external beam radiotherapy with hormonal therapy. Three cases with non-metastatic disease have no biochemical recurrence. Among four with metastatic disease, one underwent chemotherapy of Docetaxel and one had found a new lesion in lung.

Improved differentiation between ductal and acinar prostate cancer using three-dimensional histology and biomarkers

OBJECTIVE

The aim of the study was to refine the methodology for discriminating the ductal (DAP) and acinar adenocarcinomas (AAP) of the prostate and confirm that prostate carcinoma of ductal origin is a more aggressive subtype.

MATERIAL AND METHODS

A retrospective analysis of 110 consecutive radical prostatectomy cases operated on between 2000 and 2006 and worked up using large-format "two-dimensional" (2D; 4 μm thick) and "three-dimensional" (3D; 1500 μm thick) histology sections was carried out, with an average follow-up of 5.1 years. The same material was also analysed for selected biomarkers in tissue microarray blocks. The most discriminatory biomarkers were then tested on preoperative core biopsy specimens from 24 of these patients.

RESULTS

3D histology classified 97/110 (88%) cases of AAP and 13/110 (12%) DAP, which was then confirmed in 2D specimens. The DAP cases had a significantly greater frequency of pT3a and more advanced cancers, > 20 mm tumour focus, high-grade prostatic intraepithelial neoplasia, Gleason score ≥ 7, positive margin, extracapsular extension, vascular invasion, seminal vesicle infiltration, biochemical/local recurrence, regional lymph-node metastases and distant metastases. Three biomarkers in combination (chromogranin A, epidermal growth factor receptor and p53] distinguished DAP from AAP with an accuracy of 94% (area under the curve 0.94, 95% confidence interval 0.88-0.99). The same high accuracy was achieved using these three biomarkers on the preoperative specimens.

CONCLUSIONS

Both 3D histology and the three selected biomarkers can help in accurately distinguishing DAP from AAP. The clear-cut distinction of two forms of prostate cancers by the approach advocated in this paper would allow AAP patients to undergo less radical treatment and would segregate DAP patients into a subset requiring more effective treatment regimens.

Immunohistochemical verification of ductal differentiation in prostate cancer

Recent studies have shown that patients with prostate carcinomas exhibiting ductal differentiation have an unfavourable prognosis compared with those with purely acinar adenocarcinomas. We studied the expression of nine immunohistochemical markers to evaluate their value in delineating carcinomas with and without ductal differentiation. Thirteen tumours showing cellular characteristics and growth patterns typical of ductal differentiation were identified among 110 analysed prostatectomy specimens. The levels of cytoplasmic expression of chromogranine A (69% vs 19%, p = 0.0003) and nuclear expression of p53 (76% vs 12%, p < 0.0001) as well as nuclear expression of Ki-67 (69% vs 26%, p = 0.0047) in the tumour cells, were found to be statistically significantly different in the two tumour categories. Assessment of chromogranine A, p53 and Ki-67 in prostate carcinoma may serve as useful adjunctive diagnostic tools for delineating more aggressive prostate cancer cases exhibiting ductal differentiation.

Current perspectives on Gleason grading of prostate cancer

The 5-tier Gleason grading system for prostate cancer, introduced in 1966, has been proven to be one of the main independent predictors of prostate cancer outcome. This review addresses interobserver concordance in Gleason grading; the persistence of grading discrepancies with frequent upgrading from the biopsy to the prostatectomy specimen; the 2005 International Society of Urologic Pathologists' modifications to Gleason grading; the impact of this modified grading on grade migration and outcome prediction; and molecular correlates of cancer morphology. Data from the most recent years are emphasized.

Morphologic features of prostatic adenocarcinoma on ThinPrep® urinary cytology

Malignant cells of prostatic adenocarcinoma are rarely identified in urine. In most cases, this finding is associated with high stage tumor. Numerous descriptions of the morphology of prostatic adenocarcinoma have been reported using cytocentrifugated specimens. However, no specific morphologic description of prostatic adenocarcinoma in urine using liquid-based cytology has been previously described. Four cases of prostatic adenocarcinoma in urine using ThinPrep® liquid-based preparations were identified between 2002 and 2009 at the University of Wisconsin Hospital and Clinics. Three patients had either high stage tumor or metastatic disease at the time of diagnosis, while the remaining patient had low stage tumor. The morphology of each case was evaluated with specific attention to cell size, nuclear characteristics, nuclear to cytoplasmic ratio, and cytoplasmic characteristics. The resulting key features for prostatic adenocarcinoma in urine are clustering, increased nuclear to cytoplasmic ratio, and prominent nucleoli. Though typically the presence of prostatic adenocarcinoma in urine implies high stage tumor, cells of lower stage tumors may be seen in urine as well.

Digital quantification of five high-grade prostate cancer patterns, including the cribriform pattern, and their association with adverse outcome

Proper grading of the cribriform prostate cancer pattern has not previously been supported by outcome-based evidence. Among 153 men who underwent radical prostatectomy, 76 with prostate-specific antigen (PSA) failure (≥0.2 ng/mL [0.2 μg/L]) were matched to 77 without failure. Frequencies of high-grade patterns included fused small acini, 83.7%; papillary, 52.3%; large cribriform, 37.9%; small (≤12 lumens) cribriform, 17.0%; and individual cells, 22.9%. A cribriform pattern was present in 61% (46/76) of failures but 16% (12/77) of nonfailures (P < .0001). Multivariate analysis showed the cribriform pattern had the highest odds ratio for PSA failure, 5.89 (95% confidence interval, 2.53-13.70; P < .0001). The presence of both large and small cribriform patterns was significantly linked to failure. The cumulative odds ratio of failure per added square millimeter of cribriform pattern was 1.173 (P = .008), higher than for any other pattern. All 8 men with a cribriform area sum of 25 mm(2) or more had failure (range, 33-930). Regrading cribriform cancer as Gleason 5 improved the grade association with failure, although half of all cases with individual cells also had a cribriform pattern, precluding a precise determination of the independent importance of the latter. The cribriform pattern has particularly adverse implications for outcome.

Pathologic stage of prostatic ductal adenocarcinoma at radical prostatectomy: effect of percentage of the ductal component and associated grade of acinar adenocarcinoma

It is unknown whether ductal adenocarcinomas are more aggressive when matched for Gleason score (assigning the ductal component as Gleason pattern 4). Moreover, little is known whether a certain percentage of the ductal component is needed to account for its more aggressive behavior. Of 18,552 radical prostatectomies performed from 1995 to 2008, 93 cases with a ductal adenocarcinoma component were identified. Cases were classified based on their ductal/acinar ratio (<10%; ≥10% and <50%; ≥50%). There was no difference in the distribution of Gleason score 3+4=7 versus 4+3=7 between ductal and nonductal tumors, such that cases were combined as Gleason score 7. There was no age, race, and serum prostate-specific antigen difference between patients with and without ductal adenocarcinoma. Cases with ductal adenocarcinoma were less likely to be organ confined (36.6% vs 65.6%) and more likely to show seminal vesicle invasion (SVI) (19.3% vs 5.3%), P<0.0001. There was no difference in lymph node metastases or positive margins between cases with and without ductal features. An increasing percentage of the ductal component correlated with an increased risk of extraprostatic extension (P=0.04) and SVI (P<0.0001). To account for overall different Gleason scores between ductal and nonductal cases, and the effect of differing percentages of ductal features as well, the following analysis was carried out. For Gleason score 7 cases and ≥10% ductal differentiation, cases with ductal features were more likely to have nonfocal extraprostatic extension (64.0%) versus cases without ductal features (34.7%), P=0.002. In this group, there was no statistically significant difference in SVI or lymph node involvement between Gleason score 7 ductal and nonductal tumors. For Gleason score 7 cases with <10% ductal features, there was no difference in pathologic stage versus nonductal cases. There was no difference in pathologic stage between ductal and nonductal cases for Gleason score 8 to 10 cases, regardless of the percentage of the ductal component. This study shows that ductal adenocarcinoma admixed with Gleason pattern 3 is more aggressive than Gleason score 7 acinar cancer, as long as the ductal component is ≥10%. In cases with a very minor ductal component, these differences are lost. In addition, Gleason score 8 to 10 tumors with ductal features are not significantly more aggressive that acinar Gleason score 8 to 10 cancers in which the pure high-grade tumor, regardless of ductal features, determines the behavior.

Ductal adenocarcinoma of the prostate: increased mortality risk and decreased serum prostate specific antigen

PURPOSE

The clinical significance of ductal prostatic carcinoma is not well-defined. In a population based cancer registry we identified a large group of patients with ductal carcinoma to characterize the impact of the ductal subtype on presentation and survival in men with prostate cancer.

MATERIALS AND METHODS

We used a national cancer registry to identify incident cases of ductal and acinar adenocarcinoma from 1996 to 2006. We analyzed clinicopathological variables and performed Cox multivariate survival analysis. Prostate specific antigen values were available for 2004 to 2006 and used to assess differences in Gleason grade and serum prostate specific antigen between ductal and acinar cancer cases at diagnosis.

RESULTS

We identified 442,881 acinar and 371 ductal cases. Ductal cases were more likely to present with distant disease (12% vs 4%, p <0.001) and be poorly differentiated (50% vs 32%, p <0.001). Ductal histology was associated with a 30% decrease in geometric mean prostate specific antigen (adjusted coefficient 0.7, 95% CI 0.6-0.8) and more than 2-fold increased odds of prostate specific antigen less than 4.0 ng/ml (OR 2.4, 95% CI 1.4-4.0) independent of other clinicopathological variables. In men with nondistant disease at diagnosis ductal histology was associated with 2.2-fold (CI 1.4-3.5) increased disease specific mortality.

CONCLUSIONS

In what is to our knowledge the largest series of this histological subtype ductal cancer cases were more likely to present with advanced stage cancer and lower prostate specific antigen, suggesting that timely disease detection is a significant challenge. Also, men with locoregional disease were more likely to die of the disease.

Gene expression profiles of ductal versus acinar adenocarcinoma of the prostate

Ductal adenocarcinoma is an uncommon variant of prostatic adenocarcinoma with a generally more aggressive clinical course than usual acinar adenocarcinoma. However, the molecular distinction between ductal and acinar adenocarcinomas is not well characterized. The aim of this investigation was to evaluate the relatedness of ductal versus acinar prostatic adenocarcinoma by comparative gene expression profiling. Archived, de-identified, snap frozen tumor tissue from 5 ductal adenocarcinomas, 3 mixed ductal-acinar adenocarcinomas, and 11 acinar adenocarcinomas cases were analyzed. All cases of acinar and ductal adenocarcinomas were matched by Gleason grade. RNA from whole tissue sections of the 5 ductal and 11 acinar adenocarcinomas cases were subjected to gene expression profiling on Affymetrix U133Plus2 microarrays. Independently, laser-capture microdissection was also performed on the three mixed ductal-acinar cases and five pure acinar cases to isolate homogeneous populations of ductal and acinar carcinoma cells from the same tumor. Seven of these laser-capture microdissected samples (three ductal and four acinar cell populations) were similarly analyzed on U133Plus2 arrays. Analysis of data from whole sections of ductal and acinar carcinomas identified only 25 gene transcripts whose expression was significantly and at least two-fold different between ductal and acinar adenocarcinomas. A similar analysis of microdissected cell populations identified 10 transcripts, including the prolactin receptor, with more significant differences in expression of 5- to 27-fold between ductal and acinar adenocarcinomas cells. Overexpression of prolactin receptor protein in ductal versus acinar adenocarcinoma was confirmed by immunohistochemistry in an independent set of tumors. We conclude that ductal and acinar adenocarcinomas of the prostate are strikingly similar at the level of gene expression. However, several of the genes identified in this study, including the prolactin receptor, represent targets for further investigations on the molecular basis for histomorphological and clinical behavioral differences between acinar and ductal adenocarcinomas.

Ductal adenocarcinoma of the prostate: clinical features and implications after local therapy

BACKGROUND

Ductal or endometrioid adenocarcinoma of the prostate may be a subtype of prostate cancer that is amenable to aggressive local therapeutic strategies. The authors of this report investigated the clinical outcome of patients who had prostate ductal adenocarcinoma after primary radical prostatectomy or radiotherapy.

METHODS

The clinical features of 108 patients with locally confined or advanced prostate ductal adenocarcinoma who had undergone primary radical prostatectomy (surgical group, n = 76 men) or no surgery (nonsurgical group, n = 32 men) were evaluated retrospectively. Clinical records were reviewed, and Gleason scores, clinical/pathologic stages, and preoperative prostate-specific antigen levels were examined. The clinical features that were assessed included local recurrence, distant metastasis, and progression-free and overall survival after primary therapy.

RESULTS

In the surgical group, patients who had pure ductal prostate cancer survived longer (median, 13.8 years; 95% confidence interval [CI], from 13.8 years to not attained) than patients who had mixed ductal prostate cancer (median, 8.9 years; 95% CI, from 7.1 years to not attained; P = .05). In addition, the median time to local progression was shorter (2.8 years vs 4.9 years) and the median time to distant metastasis was longer (3.9 years vs 2.0 years) for patients who had pure ductal adenocarcinoma than for patients who had mixed ductal adenocarcinoma of the prostate after surgery, respectively.

CONCLUSIONS

The results of this preliminary study suggested that pure ductal prostate adenocarcinoma tends to pursue an indolent clinical course and poses an increased risk for local recurrence. Local control (particularly prostatectomy) may improve the clinical outcome of patients with pure prostate ductal adenocarcinoma. These results need to be confirmed in prospective studies.

TMPRSS2-ERG gene fusions are infrequent in prostatic ductal adenocarcinomas

Ductal adenocarcinoma of the prostate is an unusual subtype that may be associated with a more aggressive clinical course, and is less responsive to conventional therapies than the more common prostatic acinar adenocarcinoma. However, given its frequent association with an acinar component at prostatectomy, some have challenged the concept of prostatic ductal adenocarcinoma as a distinct clinicopathologic entity. We studied the occurrence of the TMPRSS2-ERG gene fusion, in 40 surgically resected ductal adenocarcinoma cases, and in their associated acinar component using fluorescence in situ hybridization. A group of 38 'pure' acinar adenocarcinoma cases matched with the ductal adenocarcinoma group for pathological grade and stage was studied as a control. Compared with the matched acinar adenocarcinoma cases, the TMPRSS2-ERG gene fusion was significantly less frequently observed in ductal adenocarcinoma (45 vs 11% of cases, P=0.002, Fisher's exact test). Here, of the ductal adenocarcinoma cases with the gene fusion, 75% were fused through deletion, and the remaining case was fused through translocation. The TMPRSS2-ERG gene fusion was also rare in the acinar component of mixed ductal-acinar tumors when compared with the pure acinar adenocarcinoma controls (5 vs 45%, P=0.001, Fisher's exact test). In 95% of the ductal adenocarcinoma cases in which a concurrent acinar component was analyzed, there was concordance for presence/absence of the TMPRSS2-ERG gene fusion between the different histologic subtypes. In the control group of pure acinar adenocarcinoma cases, 59% were fused through deletion and 41% were fused through translocation. The presence of the TMPRSS2-ERG gene fusion in some cases of prostatic ductal adenocarcinoma supports the concept that ductal adenocarcinoma and acinar adenocarcinoma may be related genetically. However, the significantly lower rate of the gene fusion in pure ductal adenocarcinoma cases underscores the fact that genetic and biologic differences exist between these two tumors that may be important for future therapeutic strategies.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Rare and unusual histological variants of prostatic carcinoma: clinical significance

We review the clinicopathological features of the following unusual histological variants of prostatic carcinoma: small cell carcinoma, ductal adenocarcinoma, sarcomatoid (carcinosarcoma), basal cell, squamous cell and adenosquamous, and urothelial carcinoma. These variants are rare and account for 5-10% of carcinomas that originate in the prostate. Some develop from acinar adenocarcinoma after hormonal or radiation therapy. They are usually aggressive tumours that often present with secondary deposits. The outcome is generally poor. Only basal cell carcinoma is seen as a low-grade carcinoma.