Histological variants of prostatic carcinoma and their significance

Morphologic patterns observed in prostate biopsy cases with discrepant grade group and molecular risk classification

BACKGROUND

Molecular-based risk classifier tests are increasingly being utilized by urologists and radiation oncologists to guide clinical decision making. The Decipher prostate biopsy test is a 22-gene RNA biomarker assay designed to predict likelihood of high-grade disease at radical prostatectomy and risk of metastasis and mortality. The test provides a risk category of low, intermediate, or high. We investigated histologic features of biopsies in which the Grade Group (GG) and Decipher risk category (molecular risk) were discrepant.

METHODS

Our institutional urologic outcomes database was searched for men who underwent prostate biopsies with subsequent Decipher testing from 2016 to 2020. We defined discrepant GG and molecular risk as either GG1-2 with high Decipher risk category or GG ≥ 3 with low Decipher risk category. The biopsy slide on which Decipher testing was performed was re-reviewed for GG and various histologic features, including % Gleason pattern 4, types of Gleason pattern 4 and 5, other "high risk" features (e.g., complex papillary, ductal carcinoma, intraductal carcinoma [IDC]), and other unusual and often "difficult to grade" patterns (e.g., atrophic carcinoma, mucin rupture, pseudohyperplastic carcinoma, collagenous fibroplasia, foamy gland carcinoma, carcinoma with basal cell marker expression, carcinoma with prominent vacuoles, and stromal reaction). Follow-up data was also obtained from the electronic medical record.

RESULTS

Of 178 men who underwent prostate biopsies and had Decipher testing performed, 41 (23%) had discrepant GG and molecular risk. Slides were available for review for 33/41 (80%). Of these 33 patients, 23 (70%) had GG1-2 (GG1 n = 5, GG2 n = 18) with high Decipher risk, and 10 (30%) had GG ≥ 3 with low Decipher risk. Of the 5 GG1 cases, one case was considered GG2 on re-review; no other high risk features were identified but each case showed at least one of the following "difficult to grade" patterns: 3 atrophic carcinoma, 1 collagenous fibroplasia, 1 carcinoma with mucin rupture, and 1 carcinoma with basal cell marker expression. Of the 18 GG2 high Decipher risk cases, 2 showed GG3 on re-review, 5 showed large cribriform and/or other high risk features, and 10 showed a "difficult to grade" pattern. Of the 10 GG ≥ 3 low Decipher risk cases, 5 had known high risk features including 2 with large cribriform, 1 with IDC, and 1 with Gleason pattern 5.

CONCLUSIONS

In GG1-2 high Decipher risk cases, difficult to grade patterns were frequently seen in the absence of other known high risk morphologic features; whether these constitute true high risk cases requires further study. In the GG ≥ 3 low Decipher risk cases, aggressive histologic patterns such as large cribriform and IDC were observed in half (50%) of cases; therefore, the molecular classifier may not capture all high risk histologic patterns.

GATA3 Expression in Prostatic Adenosquamous Carcinoma: A Potential Diagnostic Pitfall

Urothelial carcinoma and prostatic adenocarcinoma can have overlapping histologic features and in some instances pose challenges to pathologists. GATA binding protein 3 (GATA3) immunohistochemistry (IHC) is a well-established tool to aid in this specific diagnostic dilemma as it has been shown to be a sensitive marker for urothelial carcinoma and a putatively specific marker in excluding prostatic adenocarcinoma. However, in encountering an index tumor of prostatic adenosquamous carcinoma positive for GATA3, herein we sought to investigate this potential diagnostic pitfall in a larger series of tumors. In this study, we retrospectively reviewed prostatic adenosquamous carcinomas diagnosed in 17 patients across the authors' institutions and personal consult collections in the past 10 years. GATA3 IHC was either reviewed or performed on tumors not previously tested. We also recorded other immunostains that were performed at initial diagnosis. Positivity for GATA3 was found in 9 of 17 (53%) tumors, all within squamous regions (2 tumors also showed concomitant moderate GATA3 positivity within glandular elements). The GATA3 positive tumors were all positive for p63 in the 7 tumors where p63 was also performed. Of all tumors tested, NKX3.1 was positive in 100% (13/13) of the glandular elements (3 tumors also showed NKX3.1 concomitant positivity within squamous regions). In summary, when encountering a carcinoma with mixed glandular/squamous features in which prostatic origin is being considered, awareness of GATA3 immunoreactivity in a subset of prostatic adenosquamous carcinoma is critical to avoid diagnostic pitfalls.

Primary Adenosquamous Carcinoma of the Prostate With Multiple Heterogenic Metastases Demonstrated on 68 Ga-PSMA and 18 F-FDG PET/CT Imaging

ABSTRACT

A 54-year-old man presented with a 2-month history of urination disturbances. Serum prostate-specific antigen level was 4.96 ng/mL, and a possibility of benign prostate hyperplasia was raised by outside medical CT. Histopathology revealed adenosquamous carcinoma. Staging workup showed large areas of high PSMA uptake and focal intense hypermetabolism in the prostate, multiple lymphatics, bone, and pulmonary heterogenic metastases on 68 Ga-PSMA and 18 F-FDG PET/CT imaging.

A Rare Case of Neuroendocrine Prostate Cancer Detected on 68Ga - DOTANOC Positron Emission Tomography/Computed Tomography (PET/CT)

Prostate cancer is one of the most common malignancies affecting elderly men worldwide and the fifth leading cause of cancer death in men. Prostate cancer includes many histological variants with the prostatic acinar adenocarcinoma variant accounting for the majority of the diagnosed cases. Other less common histological variants are broadly classified as non-acinar carcinomas. One of the non-acinar carcinoma variants is neuroendocrine prostate cancer (NEPC). NEPC can emerge as a mechanism of treatment resistance in castration-resistant conventional prostate cancer and can also rarely be seen as a primary histological form at the time of initial diagnosis. Like other non-acinar carcinoma variants of prostate cancer, NEPC is also an aggressive variant with associated poor prognosis. Neuroendocrine tumors (NETs) are characterized by the expression of somatostatin receptors (SSTRs). Positron emission tomography/computed tomography (PET/CT) using radiolabeled somatostatin analogs like DOTANOC have been used to detect and stage these NETs. These radiolabeled somatostatin analogs also provide the option of treatment of these tumors and have been used in peptide receptor radionuclide therapy of these tumors. NEPC being a neuroendocrine malignancy also expresses SSTRs and hence can be detected with PET/CT radiotracers like 68Gallium-labeled somatostatin analogs. We here report a case of metastatic treatment-emergent NEPC detected on 68Ga - DOTANOC PET/CT.

Clinicopathological Features of Metastasis to the Oral and Maxillofacial Region-Multicenter Study

BACKGROUND

This study aimed to investigate the clinicopathological features of metastases in the oral and maxillofacial regions.

METHODS

In this retrospective study, biopsy records were obtained from referral centers for oral and maxillofacial diagnosis in Brazil, Guatemala, Mexico, and South Africa.

RESULTS

A total of 120 cases were evaluated. Of these, 53.78% affected female patients, with a mean age of 57.64 years. Intraosseous lesions were more frequent, particularly in the posterior region of the mandible (49.58%). Clinically, most cases presented with symptomatic swelling, with an average evolution time of 25 months. The clinical diagnostic hypothesis in most instances was that of a malignant lesion. Breast cancer was the most common primary tumor location in females, while lung origin was most common in males. In most cases, the primary cancer was an adenocarcinoma (44.73%). The follow-up period was available for 29 cases, and out of these, 20 had died due to the disease.

CONCLUSION

Although this is a rare condition, clinicians should be aware that any oral lesions have the possibility of being metastatic, particularly in individuals with a previous history of cancer. The findings from this study could assist clinicians in prompt diagnosing these lesions and subsequent conducting oncologic assessments and treatment.

High GLUT1 membrane expression and low PSMA membrane expression in Ductal Adenocarcinoma and Intraductal Carcinoma of the prostate

BACKGROUND

Both Ductal Adenocarcinoma (DAC) and Intraductal Carcinoma (IDC) of the prostate are generally associated with aggressive clinical behavior and poor prognosis, which were linked with discordant FDG positivity and low Prostate-Specific Membrane Antigen (PSMA) expression. A recent study only cited a DAC patient with low 68Ga-PSMA-11 PET/CT uptake but high 18F-FDG PET/CT uptake, however, there is lack of directly compared articles nor large data sets. Hence, the objective of this study was to investigate the expression of PSMA and GLUT1 in DAC and IDC-P patients.

METHODS

The study was conducted on 87 DAC or/and IDC-P patients without any treatment and 97 PAC patients with a Gleason score ≥8 of prostate biopsies and prostatectomy samples between August 2017 and August 2022. We performed immunohistochemical staining and scoring of various cancer component samples from the patients to reflect the protein expression levels of PSMA and GLUT1.

RESULTS

PSMA expression in PAC was significantly higher than in DAC/IDC-P (141.2 vs 78.6, p < 0.001). There was no significant difference in PSMA expression between DAC/IDC-P and adjacent PAC (78.6 vs 93.4, p = 0.166). GLUT1 expression was higher in DAC/IDC-P than in adjacent PAC (68.6 vs 51.3, p = 0.007), but was still lower than that in pure PAC (68.6 vs 93.1, p = 0.0014). It is worth noting that GLUT1 membrane expression in DAC/IDC-P was significantly increased than in pure PAC (13.0 vs 6.6, p = 0.025), and in PAC adjacent to DAC/IDC-P (13.0 vs 2.0, p < 0.001).

CONCLUSIONS

In DAC/IDC-P tissues, PSMA expression is low, while GLUT1 expression, especially GLUT1 membrane expression is high. These findings imply that DAC/IDC-P may have higher glucose metabolic and raise interest in targeting membrane GLUT1 as a novel anticancer strategy for DAC/IDC-P and other prostate cancer with high glucose metabolism.

Clinical Significance of Extracellular Vesicles in Prostate and Renal Cancer

Extracellular vesicles (EVs)-including apoptotic bodies, microvesicles, and exosomes-are released by almost all cell types and contain molecular footprints from their cell of origin, including lipids, proteins, metabolites, RNA, and DNA. They have been successfully isolated from blood, urine, semen, and other body fluids. In this review, we discuss the current understanding of the predictive value of EVs in prostate and renal cancer. We also describe the findings supporting the use of EVs from liquid biopsies in stratifying high-risk prostate/kidney cancer and advanced disease, such as castration-resistant (CRPC) and neuroendocrine prostate cancer (NEPC) as well as metastatic renal cell carcinoma (RCC). Assays based on EVs isolated from urine and blood have the potential to serve as highly sensitive diagnostic studies as well as predictive measures of tumor recurrence in patients with prostate and renal cancers. Overall, we discuss the biogenesis, isolation, liquid-biopsy, and therapeutic applications of EVs in CRPC, NEPC, and RCC.

Targeting Key Players of Neuroendocrine Differentiation in Prostate Cancer

Neuroendocrine prostate cancer (NEPC) is a highly aggressive subtype of prostate cancer (PC) that commonly emerges through a transdifferentiation process from prostate adenocarcinoma and evades conventional therapies. Extensive molecular research has revealed factors that drive lineage plasticity, uncovering novel therapeutic targets to be explored. A diverse array of targeting agents is currently under evaluation in pre-clinical and clinical studies with promising results in suppressing or reversing the neuroendocrine phenotype and inhibiting tumor growth and metastasis. This new knowledge has the potential to contribute to the development of novel therapeutic approaches that may enhance the clinical management and prognosis of this lethal disease. In the present review, we discuss molecular players involved in the neuroendocrine phenotype, and we explore therapeutic strategies that are currently under investigation for NEPC.

PET radiotracers for whole-body in vivo molecular imaging of prostatic neuroendocrine malignancies

Prostatic neuroendocrine malignancies represent a spectrum of diseases. Treatment-induced neuroendocrine differentiation (tiNED) in hormonally treated adenocarcinoma has been the subject of a large amount of recent research. However, the identification of neuroendocrine features in treatment-naïve prostatic tumor raises a differential diagnosis between prostatic adenocarcinoma with de novo neuroendocrine differentiation (dNED) versus one of the primary prostatic neuroendocrine tumors (P-NETs) and carcinomas (P-NECs). While [18F]FDG is being used as the main PET radiotracer in oncologic imaging and reflects cellular glucose metabolism, other molecules labeled with positron-emitting isotopes, mainly somatostatin-analogues labeled with 68Ga and prostate-specific membrane antigen (PSMA)-ligands labeled with either 18F or 68Ga, are now routinely used in departments of nuclear medicine and molecular imaging, and may be advantageous in imaging prostatic neuroendocrine malignancies. Still, the selection of the preferred PET radiotracer in such cases might be challenging. In the current review, we summarize and discuss published data on these different entities from clinical, biological, and molecular imaging standpoints. Specifically, we review the roles that [18F]FDG, radiolabeled somatostatin-analogues, and radiolabeled PSMA-ligands play in these entities in order to provide the reader with practical recommendations regarding the preferred PET radiotracers for imaging each entity. In cases of tiNED, we conclude that PSMA expression may be low and that [18F]FDG or radiolabeled somatostatin-analogues should be preferred for imaging. In cases of prostatic adenocarcinoma with dNED, we present data that support the superiority of radiolabeled PSMA-ligands. In cases of primary neuroendocrine malignancies, the use of [18F]FDG for imaging high-grade P-NECs and radiolabeled somatostatin-analogues for imaging well-differentiated P-NETs is recommended. KEY POINTS: • The preferred PET radiotracer for imaging prostatic neuroendocrine malignancies depends on the specific clinical scenario and pathologic data. • When neuroendocrine features result from hormonal therapy for prostate cancer, PET-CT should be performed with [18F]FDG or radiolabeled somatostatin-analogue rather than with radiolabeled PSMA-ligand. • When neuroendocrine features are evident in newly diagnosed prostate cancer, differentiating adenocarcinoma from primary neuroendocrine malignancy is challenging but crucial for selection of PET radiotracer and for clinical management.

Unlocking the mystery associated with infertility and prostate cancer: an update

Male-specific reproductive disorders and cancers have increased intensely in recent years, making them a significant public health problem. Prostate cancer (PC) is the most often diagnosed cancer in men and is one of the leading causes of cancer-related mortality. Both genetic and epigenetic modifications contribute to the development and progression of PC, even though the exact underlying processes causing this disease have yet to be identified. Male infertility is also a complex and poorly understood phenomenon believed to afflict a significant portion of the male population. Chromosomal abnormalities, compromised DNA repair systems, and Y chromosome alterations are just a few of the proposed explanations. It is becoming widely accepted that infertility shares a link with PC. Much of the link between infertility and PC is probably attributable to common genetic defects. This article provides an overview of PC and spermatogenic abnormalities. This study also investigates the link between male infertility and PC and uncovers the underlying reasons, risk factors, and biological mechanisms contributing to this association.

A case of metastatic adenoid cystic (basal cell) carcinoma of the prostate: Systemic therapy for a rare disease

BACKGROUND

Metastatic adenoid cystic (basal cell) carcinoma of the prostate is an exceedingly rare disease entity. As a result, no current consensus exists for optimal systemic therapy.

METHODS

We present a patient with metastatic adenoid cystic (basal cell) carcinoma of the prostate who subsequently received systemic treatment, including chemotherapy and immunotherapy. We comprehensively reviewed all published data on therapy outcomes in advanced disease.

RESULTS

Our patient benefited from combination chemotherapy (carboplatin and paclitaxel), with objective radiographic response and reduction in cancer-related pain. However, chemotherapy was stopped due to cumulative neurotoxicity, and subsequent immunotherapy with atezolizumab did not produce any response. Our literature review revealed inconsistent outcomes with various treatments but showed most promise with chemotherapy. Targeted therapy and immunotherapy seem to benefit specific cases, and androgen deprivation therapy had minimal evidence of benefit.

CONCLUSION

Based on the findings of our case report and literature review, we suggest platinum-based chemotherapy doublets as first-line treatment for metastatic cases of adenoid cystic (basal cell) carcinoma of the prostate, reserving targeted therapy or immunotherapy for select cases based upon molecular profiles.

Pleomorphic giant cell carcinoma of the prostate: clinicopathologic analysis and oncological outcomes

We report on the clinicopathologic features of 27 pleomorphic giant cell carcinoma (PGCC) cases of the prostate identified in 20 patients with an age range of 51 to 84 years (68 ± 9; median 71 years). Charlson comorbidity index ranged from 3 to 12. Serum PSA ranged from 4.30 to 662 ng/mL (median 13 ng/mL). On histologic examination, bizarre giant cells with pleomorphic nuclei characterized pleomorphic giant cell carcinoma of the prostate. PGCC component was present in 5% to 100%, with half of the patients presenting with ≥ 20%. Half of the patients initially presented with T4 and 26% with T3 disease. All patients were considered Gleason scores of 9 to 10 (ISUP grade 5). A combination of hormone therapy with chemotherapy with or without radiation therapy was applied in 68% of patients. On follow-up, 14 patients (52%) were alive with disease (1-69 months) or dead of disease (1-38 months). Patients diagnosed earlier with lower TNM stage had longer survival than those diagnosed at a later T-stage or with metastatic disease (p = 0.02). The percentage of PGCC was not related to survival in the current study. Molecular alterations in 3 samples showed a microsatellite-stable disease with low tumor mutation burden and variable PTEN, PTCH1, KDM6A, ARv7, and PIK3CA loss/alteration, TP53 mutation, TMPRSS2-ERG fusion, and MYC, PIK3CB, RICTOR, or IRS2 amplification. Our findings suggest that PGCC is a rare and aggressive subtype of prostate carcinoma whose recognition may steer clinicians to adopt more aggressive treatments and investigate new therapeutic strategies.

The KDM5B and KDM1A lysine demethylases cooperate in regulating androgen receptor expression and signalling in prostate cancer

Histone H3 lysine 4 (H3K4) methylation is key epigenetic mark associated with active transcription and is a substrate for the KDM1A/LSD1 and KDM5B/JARID1B lysine demethylases. Increased expression of KDM1A and KDM5B is implicated in many cancer types, including prostate cancer (PCa). Both KDM1A and KDM5B interact with AR and promote androgen regulated gene expression. For this reason, there is great interested in the development of new therapies targeting KDM1A and KDM5B, particularly in the context of castrate resistant PCa (CRPC), where conventional androgen deprivation therapies and androgen receptor signalling inhibitors are no longer effective. As there is no curative therapy for CRPC, new approaches are urgently required to suppress androgen signalling that prevent, delay or reverse progression to the castrate resistant state. While the contribution of KDM1A to PCa is well established, the exact contribution of KDM5B to PCa is less well understood. However, there is evidence that KDM5B is implicated in numerous pro-oncogenic mechanisms in many different types of cancer, including the hypoxic response, immune evasion and PI3/AKT signalling. Here we elucidate the individual and cooperative functions of KDM1A and KDM5B in PCa. We show that KDM5B mRNA and protein expression is elevated in localised and advanced PCa. We show that the KDM5 inhibitor, CPI-455, impairs androgen regulated transcription and alternative splicing. Consistent with the established role of KDM1A and KDM5B as AR coregulators, we found that individual pharmacologic inhibition of KDM1A and KDM5 by namoline and CPI-455 respectively, impairs androgen regulated transcription. Notably, combined inhibition of KDM1A and KDM5 downregulates AR expression in CRPC cells. Furthermore, combined KDM1A and KDM5 inhibition impairs PCa cell proliferation and invasion more than individual inhibition of KDM1A and KDM5B. Collectively our study has identified individual and cooperative mechanisms involving KDM1A and KDM5 in androgen signalling in PCa. Our findings support the further development of KDM1A and KDM5B inhibitors to treat advanced PCa. Further work is now required to confirm the therapeutic feasibility of combined inhibition of KDM1A and KDM5B as a novel therapeutic strategy for targeting AR positive CRPC.

The rising incidence of ductal adenocarcinoma and intraductal carcinoma of the prostate: Diagnostic accuracy of biopsy, MRI-visibility, and outcomes

INTRODUCTION

Ductal adenocarcinoma (DA) and intraductal carcinoma (IDC) of the prostate are associated with higher stage disease at radical prostatectomy (RP). We evaluated diagnostic accuracy of biopsy, MRI-visibility, and outcomes for patients undergoing RP with DA/IDC histology compared to pure acinar adenocarcinoma (AA) of the prostate.

MATERIALS AND METHODS

A retrospective cohort study of men receiving RP between 2014 and 2021 revealing AA, DA, or IDC on final pathology was conducted. Multivariable logistic regression and Cox proportional hazards regression models were employed.

RESULTS

A total of 609 patients were included with 103 found to have DA/IDC. Patients with DA/IDC were older and had higher PSA, biopsy grade group (GG), RP GG, and other pathologic findings (extraprostatic extension, lymphovascular invasion, perineural invasion, pN stage) compared to AA patients (all P < 0.05). On multivariable analysis, higher age, RP GG, and pT3a were associated with DA/IDC on RP (all P < 0.05). Sensitivity and specificity of biopsy compared to RP for diagnosis of DA/IDC was 29.1% (16.7% DA, 27.8% IDC) and 96.6% (99.3% DA, 96.6% IDC), respectively. In a subset of 281 men receiving MRI, PI-RADS distribution was similar for patients with DA/IDC vs. AA (90.7% vs. 80.7% with PI-RADS 4-5 lesions, P = 0.23) with slightly higher biopsy sensitivity (41.9%). DA/IDC was associated with worse BCR (HR = 1.77, P = 0.02) but not biopsy DA/IDC (P = 0.90).

CONCLUSIONS

Sensitivity of prostate biopsy was low for detection of DA/IDC histology at RP. Patients with DA/IDC histology had unfavorable pathologic features at RP and worse BCR. Of patients with DA/IDC at RP, 90.7% were categorized as PI-RADS 4 to 5 on preoperative MRI.

Deep UV Microscopy Identifies Prostatic Basal Cells: An Important Biomarker for Prostate Cancer Diagnostics

Objective and Impact Statement. Identifying benign mimics of prostatic adenocarcinoma remains a significant diagnostic challenge. In this work, we developed an approach based on label-free, high-resolution molecular imaging with multispectral deep ultraviolet (UV) microscopy which identifies important prostate tissue components, including basal cells. This work has significant implications towards improving the pathologic assessment and diagnosis of prostate cancer. Introduction. One of the most important indicators of prostate cancer is the absence of basal cells in glands and ducts. However, identifying basal cells using hematoxylin and eosin (H&E) stains, which is the standard of care, can be difficult in a subset of cases. In such situations, pathologists often resort to immunohistochemical (IHC) stains for a definitive diagnosis. However, IHC is expensive and time-consuming and requires more tissue sections which may not be available. In addition, IHC is subject to false-negative or false-positive stains which can potentially lead to an incorrect diagnosis. Methods. We leverage the rich molecular information of label-free multispectral deep UV microscopy to uniquely identify basal cells, luminal cells, and inflammatory cells. The method applies an unsupervised geometrical representation of principal component analysis to separate the various components of prostate tissue leading to multiple image representations of the molecular information. Results. Our results show that this method accurately and efficiently identifies benign and malignant glands with high fidelity, free of any staining procedures, based on the presence or absence of basal cells. We further use the molecular information to directly generate a high-resolution virtual IHC stain that clearly identifies basal cells, even in cases where IHC stains fail. Conclusion. Our simple, low-cost, and label-free deep UV method has the potential to improve and facilitate prostate cancer diagnosis by enabling robust identification of basal cells and other important prostate tissue components.

Pure ductal adenocarcinoma of the prostate protruding into the prostatic urethra: A case report of MRI findings and literature review

Ductal adenocarcinoma of the prostate (DCa) is the histological variant of prostatic carcinoma. The macroscopic finding of DCa arising from primary duct by urethroscopy is papillary excrescences in the prostatic urethra. But the finding of MRI remains poorly understood, since there is no coherent report on the MRI finding of DCa arising from primary duct. We herein report a case of DCa arising from primary duct and forming papillary excrescences in the prostatic urethra. The patient was a male in his 70s and presented with gross hematuria a few days ago. Blood test showed elevated prostate specific antigen (PSA). Prostate MRI was performed. There were two lesions in the prostatic urethra and the right transition zone (TZ). On T₂-weighted image (T2WI), the lesion in the prostatic urethra was identifiable, but the lesion in the right TZ was difficult to identify. On diffusion-weighted image (DWI), both lesions showed hyperintense signal and could be identified, and there was continuity between them. Urethroscopy was performed, there was the lesion with papillary excrescences developing from the right dorsal side of prostatic urethra. Transurethral resection of the prostate was performed. The pathological diagnosis was DCa (pure type). A review of previous literature showed that DCa had a slightly hypointense signal on T2WI. It may be difficult to identify DCa in the TZ because DCa and the TZ show similar signals on T2WI. DWI may be useful to accurately assess DCa arising from primary duct.

Oligometastatic Squamous Cell Transformation From Metastatic Prostate Adenocarcinoma Treated With Systemic and Focal Therapy: A Case Report

Transformation to squamous cell carcinoma (SCC) after initial treatment of a primary prostate adenocarcinoma is rare and typically results in rapid treatment-refractory disease progression and death. Here, we present a case of a 70-year-old man who was initially treated with prostatectomy and radiotherapy, and later developed bone metastases. After commencing systemic therapy with androgen deprivation therapy (ADT) and apalutamide, his prostate-specific antigen (PSA) declined to undetectable levels, yet short-interval imaging demonstrated oligo-progression at T4, with biopsy specimen demonstrating pure SCC. Molecular profiling of both the primary prostate tumor and T4 demonstrated alterations in TMPRSS2-ERG, TP53, and FOXA1 confirming site of origin, with loss of RNF43 in the squamous metastasis. He was treated with stereotactic body radiation therapy to the SCC metastasis and continued on ADT and apalutamide with stable disease for a year post-radiation. This case highlights the importance of imaging to detect non–PSA-producing metastatic disease, the utility of radiation therapy in oligo-progression, and use of molecular profiling to provide insights into the pathogenesis of histologic transformation.

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.

18F-PSMA-11 PET/MRI in Prostate Adenocarcinoma With Mucinous Features

ABSTRACT

Primary mucinous tumors involving the prostate gland are rare. We describe MRI and 18F-PSMA-11 PET/MRI findings in a case of prostate adenocarcinoma with mucinous features. The prostate tumor showed inhomogeneous hyperintensity on T2-weighted images due to high extracellular mucin content and inhomogeneous 18F-PSMA-11 uptake with SUVmax of 12.5. This case indicates PSMA PET imaging may be helpful for detection of this uncommon variant of prostate adenocarcinoma.

Sleep disorders and prostate cancer prognosis: biology, epidemiology, and association with cancer development risk

Sleep is crucial for the maintenance of health and well-being. Sleep disorders can result in physiological consequences and are associated with several health issues, including cancer. Cancer is one of the most significant health problems in the world. In Western countries, prostate cancer is the most prevalent noncutaneous cancer among men. Epidemiological studies showed that one in nine men will have this disease during their life. Many factors influence prostate cancer and the tumor niche, including endogenous hormones, family history, diet, and gene mutations. Disruption of the circadian cycle by sleep disorders or other factors has been suggested as a novel and important risk factor for prostate cancer and its tumorigenesis. This review presents information regarding the epidemiological and biological aspects of prostate cancer, and discusses the impact of sleep physiology and sleep disorders on this type of cancer, highlighting possible associations with risk of cancer development.

Intraductal Adenocarcinoma of the Prostate With Cribriform or Papillary Ductal Morphology: Rare Biopsy Cases Lacking Associated Invasive High-grade Carcinoma

Prostatic duct adenocarcinoma, characterized by pseudostratified columnar epithelium, has historically been considered invasive carcinoma, although it may commonly have an intraductal component. Usual (acinar) intraductal carcinoma of the prostate (IDC-P) is a noninvasive high-risk lesion typically associated with high-grade, high-stage prostate cancer. Whereas there have been rare biopsy studies of pure acinar IDC-P or IDC-P associated with only low-grade carcinoma, there have been no analogous series of IDC-P with cribriform or papillary ductal morphology on biopsy unassociated with invasive high-grade carcinoma. We identified 14 patients with biopsies showing IDC-P with ductal morphology, defined as prostatic duct adenocarcinoma confined to glands/ducts with immunohistochemically proven retention of basal cells. Our series includes 12 patients with pure IDC-P and 2 patients with concurrent low-volume Grade Group 1 invasive cancer in unassociated cores. Three patients underwent radical prostatectomy: 2/3 had high-grade cancer in their resection specimen (Grade Group 3, Grade Group 5), including 1 with advanced stage and nodal metastases; 1/3 had Grade Group 1 organ-confined carcinoma and spatially distinct IDC-P with ductal morphology. Five men had only follow-up biopsies: 2/5 had cancer (Grade Group 2, Grade Group 4); 1/5 had IDC-P (on 2 repeat biopsies); and 2/5 had benign transurethral resection of the prostate. In all 5 cases with invasive cancer, the invasive portion was comprised purely of acinar morphology; no invasive ductal component was identified. Five patients did not have follow-up biopsies and were treated with radiation therapy±androgen deprivation. One patient had no follow-up information. In an analogous situation to acinar IDC-P, we propose that rarely there is a precursor form of ductal adenocarcinoma that can exist without concurrent invasive high-grade carcinoma and propose the term "IDC-P with ductal morphology," consistent with the terminology for acinar prostate adenocarcinoma. Until more evidence is accumulated, we recommend reporting and treating patients with IDC-P with ductal morphology in a manner analogous to those with acinar IDC-P. As with pure IDC-P with acinar morphology, we would also recommend not grading pure IDC-P with ductal morphology. Finally, we propose a new addition to the diagnostic criteria of IDC-P to include intraductal lesions with ductal morphology consisting of papillary fronds or cribriform lesions lined by cytologically atypical pseudostratified epithelium.

Exploring anti-androgen therapies in hormone dependent prostate cancer and new therapeutic routes for castration resistant prostate cancer

Androgen deprivation therapies (ADTs) are important treatments which inhibit androgen-induced prostate cancer (PCa) progression by either preventing androgen biosynthesis (e.g. abiraterone) or by antagonizing androgen receptor (AR) function (e.g. bicalutamide, enzalutamide, darolutamide). A major limitation of current ADTs is they often remain effective for limited durations after which patients commonly progress to a lethal and incurable form of PCa, called castration-resistant prostate cancer (CRPC) where the AR continues to orchestrate pro-oncogenic signalling. Indeed, the increasing numbers of ADT-related treatment-emergent neuroendocrine-like prostate cancers (NePC), which lack AR and are thus insensitive to ADT, represents a major therapeutic challenge. There is therefore an urgent need to better understand the mechanisms of AR action in hormone dependent disease and the progression to CRPC, to enable the development of new approaches to prevent, reverse or delay ADT-resistance. Interestingly the AR regulates distinct transcriptional networks in hormone dependent and CRPC, and this appears to be related to the aberrant function of key AR-epigenetic coregulator enzymes including the lysine demethylase 1 (LSD1/KDM1A). In this review we summarize the current best status of anti-androgen clinical trials, the potential for novel combination therapies and we explore recent advances in the development of novel epigenetic targeted therapies that may be relevant to prevent or reverse disease progression in patients with advanced CRPC.

Comparative pathology of dog and human prostate cancer

Though relatively rare in dogs, prostate cancer (PCa) is the most common non-cutaneous cancer in men. Human and canine prostate glands share many functional, anatomical and physiological features. Due to these similarities, canine PCa has been proposed as a model for PCa in men. PCa is typically androgen-dependent at diagnosis in men and for this reason, androgen deprivation therapies (ADT) are important treatments for advanced PCa in men. In contrast, there is some evidence that PCa is diagnosed more commonly in castrate dogs, at which point, limited therapeutic options are available. In men, a major limitation of current ADT is that progression to a lethal and incurable form of PCa, termed castrate-resistant prostate cancer (CRPC), is common. There is, therefore, an urgent need for a better understanding of the mechanism of PCa initiation and progression to CRPC to enable the development of novel therapeutic approaches. This review focuses on the functional, physiological, endocrine and histopathological similarities and differences in the prostate gland of these species. In particular, we focus on common physiological roles for androgen signalling in the prostate of men and dogs, we review the short- and longer-term effects of castration on PCa incidence and progression in the dog and relate how this knowledge may be relevant to understanding the mechanisms of CRPC in men.

Recent advances in tissue stem cells

Stem cells are undifferentiated cells capable of self-renewal and differentiation, giving rise to specialized functional cells. Stem cells are of pivotal importance for organ and tissue development, homeostasis, and injury and disease repair. Tissue-specific stem cells are a rare population residing in specific tissues and present powerful potential for regeneration when required. They are usually named based on the resident tissue, such as hematopoietic stem cells and germline stem cells. This review discusses the recent advances in stem cells of various tissues, including neural stem cells, muscle stem cells, liver progenitors, pancreatic islet stem/progenitor cells, intestinal stem cells, and prostate stem cells, and the future perspectives for tissue stem cell research.

Vasohibin-1 expression as a biomarker of aggressive nature in ductal adenocarcinoma of the prostate: a retrospective cohort study at two centres in Japan

OBJECTIVES

Vasohibin-1 (VASH1) is an endogenous angiogenesis regulator expressed in activated vascular endothelial cells. We previously reported that high VASH1 expression is a predictor of progression in acinar adenocarcinoma of the prostate. In this study, we evaluated the characteristics of ductal adenocarcinoma of the prostate by comparing the level of VASH1 expression between ductal and acinar adenocarcinoma specimens.

DESIGN AND SETTING

A retrospective cohort study at two centres in Japan.

PARTICIPANTS

Among the 1495 patients who underwent radical prostatectomy or transurethral resection for the past 15 years, a total of 14 patients diagnosed with ductal adenocarcinoma and 20 patients diagnosed with acinar adenocarcinoma with a Gleason score of 4+4 were included.

INTERVENTIONS

We immunohistochemically examined the CD34 expression as the microvessel density (MVD) and activated endothelial cells as the VASH1 density (vessels per mm²).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the association of MVD and VASH1 density between ductal and acinar adenocarcinoma, and the secondary outcome was their oncological outcomes.

RESULTS

Nine patients (64.3%) with ductal adenocarcinoma were diagnosed at an advanced clinical stage, and five patients (35.7%) died from cancer during a median follow-up of 56.0 months. The VASH1 densities (mean±SD) in ductal and acinar adenocarcinoma were 45.1±18.5 vs 16.1±21.0 (p<0.001), respectively, while the MVD (mean±SD) in ductal and acinar adenocarcinoma were 65.3±21.9 vs 80.8±60.7 (p=0.666), respectively. The 5-year cancer-specific survival rates for high and low VASH1 expression were 70.0% and 100.0% (p=0.006), respectively. High VASH1 expression and a diagnosis of ductal adenocarcinoma were significant predictors of cancer-specific survival.

CONCLUSIONS

Ductal adenocarcinoma was more aggressive and had higher VASH1 expression than acinar adenocarcinoma, although MVD was equivalent. These results indicate that VASH1 expression may serve as a novel biomarker for the aggressive nature of ductal adenocarcinoma.

Survival after radical prostatectomy vs. radiation therapy in ductal carcinoma of the prostate

AIM

To compare cancer-specific mortality (CSM) rates between radical prostatectomy (RP) vs. external beam radiotherapy (RT) in patients with ductal carcinoma (DC) of the prostate.

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results (SEER) database (2004-2016), we identified 369 DC patients, of whom 303 (82%) vs. 66 (18%) were treated with RP vs. RT, respectively. Kaplan-Meier plots and uni- and stepwise multivariate Cox regression models addressed CSM in the unmatched population. After propensity score matching (PSM) and inverse probability of treatment weighting (IPTW), Kaplan-Meier curve and Cox regression models tested the effect of RP vs RT on CSM.

RESULTS

Overall, RT patients were older, harbored higher PSA values, higher clinical T and higher Gleason grade groups. 5-year CSM rates were respectively 4.2 vs. 10% for RP vs. RT (HR 0.40, 95% CI 0.16-0.99, p = 0.048, favoring RP). At step-by-step multivariate Cox regression, after adding possible confounders, the central tendency of the HR for RP vs. RT approached 1. PSM resulted into 124 vs. 53 patients treated respectively with RP vs. RT. After PSM, as well as after IPTW, the protective effect of RP was no longer present (HR 1.16, 95% CI 0.23-5.73, p = 0.9 and 0.97, 95% CI 0.35-2.66, p = 0.9, respectively).

CONCLUSIONS

Although CSM rate of ductal carcinoma RP patients is lower of that of RT patients, this apparent benefit disappears after statistical adjustment for population differences.

MRI Finding of Prostatic Ductal Adenocarcinoma

Ductal adenocarcinoma is a variant of prostatic adenocarcinoma, originating from the epithelial lining of the primary and secondary ducts of the prostate. We report a 63-year-old male with prostatic ductal adenocarcinoma, presenting as urinary retention and a prostate-specific antigen (PSA) level of 11.71 ng/mL and biopsy-proven prostate cancer (Gleason score 3 + 3). MRI showed 2 hemorrhagic, multilocular cysts projecting into the bladder side from the prostatic inner gland and between the prostate and the right seminal vesicle. The prostate inner gland showed high signal intensity on the T2-weighted image and included tiny hyperintense spots on the fat-suppression T1-weighted image. In the part of the border of the hemorrhagic, multilocular cyst, a solid portion showing slight low intensity on T1-weigthed imaging and markedly restricted diffusion was observed, suggesting prostate cancer. He underwent total prostatectomy, and ductal adenocarcinoma (Gleason score 4 + 4) in the prostate inner gland and multilocular cysts was pathologically diagnosed. After the operation, his PSA level gradually increased, and MRI 8 months after the operation showed a vesical multilocular cyst, suggesting local recurrence. After he underwent radiation therapy and hormonal therapy, PSA level decreased, and no re-recurrence was observed during 8 years. We suggest its inclusion in the differential diagnosis of cases of prostatic ductal adenocarcinoma's multiloculated cystic formation around the prostate and the bladder.

[Localized prostate cancer]

Prostate cancer is the most prevalent noncutaneous cancer in men. The Gleason grading is considered to be the strongest prognostic parameter regarding progression-free survival and overall survival. The original grading system has been modified during the last decade resulting in a more precise prognostic tool. The pretreatment Gleason score guides clinical management and is a key component in S3 guidelines for prostate cancer. In addition to Gleason score several other histologic findings in prostate needle biopsy influence patient management. In this second part of our CME series about prostate cancer, we will discuss the diagnosis of prostate cancer and current guidelines for reporting prostate cancer. In addition, we will highlight prostate lesions of urothelial origin and neuroendocrine prostate cancer as well as prognostic biomarkers.

Molecular events in neuroendocrine prostate cancer development

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer. NEPC arises de novo only rarely; the disease predominantly develops from adenocarcinoma in response to drug-induced androgen receptor signalling inhibition, although the mechanisms behind this transdifferentiation are a subject of debate. The survival of patients with NEPC is poor, and few effective treatment options are available. To improve clinical outcomes, understanding of the biology and molecular mechanisms regulating NEPC development is crucial. Various NEPC molecular drivers make temporal contributions during NEPC development, and despite the limited treatment options available, several novel targeted therapeutics are currently under research.

BET Bromodomain Inhibition Blocks an AR-Repressed, E2F1-Activated Treatment-Emergent Neuroendocrine Prostate Cancer Lineage Plasticity Program

PURPOSE

Lineage plasticity in prostate cancer-most commonly exemplified by loss of androgen receptor (AR) signaling and a switch from a luminal to alternate differentiation program-is now recognized as a treatment resistance mechanism. Lineage plasticity is a spectrum, but neuroendocrine prostate cancer (NEPC) is the most virulent example. Currently, there are limited treatments for NEPC. Moreover, the incidence of treatment-emergent NEPC (t-NEPC) is increasing in the era of novel AR inhibitors. In contradistinction to de novo NEPC, t-NEPC tumors often express the AR, but AR's functional role in t-NEPC is unknown. Furthermore, targetable factors that promote t-NEPC lineage plasticity are also unclear.

EXPERIMENTAL DESIGN

Using an integrative systems biology approach, we investigated enzalutamide-resistant t-NEPC cell lines and their parental, enzalutamide-sensitive adenocarcinoma cell lines. The AR is still expressed in these t-NEPC cells, enabling us to determine the role of the AR and other key factors in regulating t-NEPC lineage plasticity.

RESULTS

AR inhibition accentuates lineage plasticity in t-NEPC cells-an effect not observed in parental, enzalutamide-sensitive adenocarcinoma cells. Induction of an AR-repressed, lineage plasticity program is dependent on activation of the transcription factor E2F1 in concert with the BET bromodomain chromatin reader BRD4. BET inhibition (BETi) blocks this E2F1/BRD4-regulated program and decreases growth of t-NEPC tumor models and a subset of t-NEPC patient tumors with high activity of this program in a BETi clinical trial.

CONCLUSIONS

E2F1 and BRD4 are critical for activating an AR-repressed, t-NEPC lineage plasticity program. BETi is a promising approach to block this program.

An overview of the latest in state-of-the-art murine models for prostate cancer

INTRODUCTION

Prostate cancer (PCa) is a complex, heterogenous and multifocal disease, which is debilitating for patients and often fatal - due to bone metastasis and castration-resistant cancer. The use of murine models that mimic human disease has been crucial in the development of innovative therapies and for better understanding the mechanisms associated with initiation and progression of PCa.

AREAS COVERED

This review presents a critical analysis of murine models for the study of PCa, highlighting their strengths, weaknesses and applications.

EXPERT OPINION

In animal models, disease may not occur exactly as it does in humans, and sometimes the levels of efficacy that certain treatments obtain in animal models cannot be translated into clinical practice. To choose the most appropriate animal model for each research work, it is crucial to understand the anatomical and physiological differences between the mouse and the human prostate, while it is also important to identify biological similarities and differences between murine and human prostate tumors. Although significant progress has already been made, thanks to many years of research and study, the number of new challenges and obstacles to overcome mean there is a long and difficult road still to travel.

Predicting prostate cancer specific-mortality with artificial intelligence-based Gleason grading

Background

Gleason grading of prostate cancer is an important prognostic factor, but suffers from poor reproducibility, particularly among non-subspecialist pathologists. Although artificial intelligence (A.I.) tools have demonstrated Gleason grading on-par with expert pathologists, it remains an open question whether and to what extent A.I. grading translates to better prognostication.

Methods

In this study, we developed a system to predict prostate cancer-specific mortality via A.I.-based Gleason grading and subsequently evaluated its ability to risk-stratify patients on an independent retrospective cohort of 2807 prostatectomy cases from a single European center with 5–25 years of follow-up (median: 13, interquartile range 9–17).

Results

Here, we show that the A.I.’s risk scores produced a C-index of 0.84 (95% CI 0.80–0.87) for prostate cancer-specific mortality. Upon discretizing these risk scores into risk groups analogous to pathologist Grade Groups (GG), the A.I. has a C-index of 0.82 (95% CI 0.78–0.85). On the subset of cases with a GG provided in the original pathology report (n = 1517), the A.I.’s C-indices are 0.87 and 0.85 for continuous and discrete grading, respectively, compared to 0.79 (95% CI 0.71–0.86) for GG obtained from the reports. These represent improvements of 0.08 (95% CI 0.01–0.15) and 0.07 (95% CI 0.00–0.14), respectively.

Conclusions

Our results suggest that A.I.-based Gleason grading can lead to effective risk stratification, and warrants further evaluation for improving disease management.

Gleason grading is the process by which pathologists assess the morphology of prostate tumors. The assigned Grade Group tells us about the likely clinical course of people with prostate cancer and helps doctors to make decisions on treatment. The process is complex and subjective, with frequent disagreement amongst pathologists. In this study, we develop and evaluate an approach to Gleason grading based on artificial intelligence, rather than pathologists’ assessment, to predict risk of dying of prostate cancer. Looking back at tumors and data from 2,807 people diagnosed with prostate cancer, we find that our approach is better at predicting outcomes compared to grading by pathologists alone. These findings suggest that artificial intelligence might help doctors to accurately determine the probable clinical course of people with prostate cancer, which, in turn, will guide treatment.

Wulczyn et al. utilise a deep learning-based Gleason grading model to predict prostate cancer-specific mortality in a retrospective cohort of radical prostatectomy patients. Their model enables improved risk stratification compared to pathologists’ grading and demonstrates the potential for computational pathology in the management of prostate cancer.

A Review Leveraging a Rare and Unusual Case of Basal Cell Carcinoma of the Prostate

Basal cell carcinoma (BCC) is a rare nonacinar variant of prostatic carcinoma. In spite of prostatic acinar adenocarcinoma being one of the most common carcinomas in prostate, <100 prostatic BCC cases have been reported to date. Adenoid cystic/cribriform histology has been described in varying proportions to occur in prostatic BCC and is reported to be associated with aggressive behavior and high risk of metastasis. Herein, we present a case of prostatic BCC with adenoid cystic morphology, comprehensively describe its immunohistochemical and MYB/MYBL1 gene rearrangement findings, discuss its differential diagnosis, and review the literature of this rare entity.

First case of ductal adenocarcinoma of the prostate with MAP3K1 homozygous deletion

INTRODUCTION

Ductal adenocarcinoma of the prostate is a rare prostate cancer variant and associated with higher stage and greater risk of mortality. Optimal systemic therapy for metastatic ductal adenocarcinoma is not known.

CASE PRESENTATION

A 67-year-old man presented with ductal adenocarcinoma of the prostate accompanied by multiple lung metastases and advanced bone metastases. We performed channel transurethral resection of the prostate and confirmed the diagnosis of ductal adenocarcinoma of the prostate. DNA sequencing identified a TP53 somatic point mutation (p.Gly245Ser) as the pathogenic variant. Furthermore, a homozygous deletion was observed in mitogen-activated protein kinase kinase kinase 1. The patient received enzalutamide but deceased 5 months after presenting to our institution.

CONCLUSION

To our knowledge, this is the first report of ductal adenocarcinoma of the prostate with a mitogen-activated protein kinase kinase kinase 1 homozygous deletion. Accumulation of whole-exome sequencing data is expected to inform future advances in therapy development.

Ductal variant prostate carcinoma is associated with a significantly shorter metastasis-free survival

BACKGROUND

Ductal adenocarcinoma is an uncommon prostate cancer variant. Previous studies suggest that ductal variant histology may be associated with worse clinical outcomes, but these are difficult to interpret. To address this, we performed an international, multi-institutional study to describe the characteristics of ductal adenocarcinoma, particularly focussing on the effect of presence of ductal variant cancer on metastasis-free survival.

METHODS

Patients with ductal variant histology from two institutional databases who underwent radical prostatectomies were identified and compared with an independent acinar adenocarcinoma cohort. After propensity score matching, the effect of the presence of ductal adenocarcinoma on time to biochemical recurrence, initiation of salvage therapy and the development of metastatic disease was determined. Deep whole-exome sequencing was performed for selected cases (n = 8).

RESULTS

A total of 202 ductal adenocarcinoma and 2037 acinar adenocarcinoma cases were analysed. Survival analysis after matching demonstrated that patients with ductal variant histology had shorter salvage-free survival (8.1 versus 22.0 months, p = 0.03) and metastasis-free survival (6.7 versus 78.6 months, p < 0.0001). Ductal variant histology was consistently associated with RB1 loss, as well as copy number gains in TAP1, SLC4A2 and EHHADH.

CONCLUSIONS

The presence of any ductal variant adenocarcinoma at the time of prostatectomy portends a worse clinical outcome than pure acinar cancers, with significantly shorter times to initiation of salvage therapies and the onset of metastatic disease. These features appear to be driven by uncoupling of chromosomal duplication from cell division, resulting in widespread copy number aberration with specific gain of genes implicated in treatment resistance.

Intracranial Metastasis from Prostate Cancer: Investigation, Incidence, and Imaging Findings in a Large Cohort of Australian Men

Objectives:

Prostate cancer metastasizing to the brain is remarkably uncommon, with the incidence never having been described in the modern setting. The objective of this study was to determine the incidence and imaging pattern of intracranial metastasis from prostate cancer in a large cohort of Australian men with prostate cancer.

Material and Methods:

Retrospective review was undertaken of imaging reports for all known prostate cancer patients, who underwent an imaging examination inclusive of the brain, between July 1, 2014, and July 1, 2020. Once an intracranial lesion was identified, all available imaging and clinical notes were reviewed.

Results:

A total of 5644 imaging examinations which included the brain were identified in 4341 prostate cancer patients. The majority (92.1%) of examinations were 68-Gallium-labeled prostate-specific membrane antigen (⁶⁸Ga-PSMA) positron emission tomography/computed tomography (PET/CT). Eight patients were identified as having an intracranial metastasis from prostate cancer, yielding an incidence of 0.18%. All patients had a Gleason score of 9 (where known), and the majority of patients (5/8) had a non-acinar variant of prostate cancer. At the time of diagnosis of intracranial metastasis, all patients had extensive metastatic disease. Imaging characteristics of the intracranial lesions were highly variable.

Conclusion:

The incidence of intracranial metastasis in prostate cancer patients has never been well-established. In this study, we determined the incidence as being 0.18%. Given the majority of metastasis constituted unexpected findings on routine restaging ⁶⁸Ga-PSMA PET/CT, the incidence determined in our study is arguably the most accurate and clinically relevant described to date.

Pleomorphic giant cell carcinoma of prostate: Rare tumor with unique clinicopathological, immunohistochemical, and molecular features

Pleomorphic giant cell carcinoma (PGCC) of the prostate is a rare entity categorized as a variant of prostatic acinar adenocarcinoma in the 2016 World Health Organization (WHO) classification system. PGCC differs from conventional prostatic adenocarcinoma by having bizarre, markedly enlarged, and pleomorphic cells. It differs from high grade urothelial carcinoma by negativity for urothelial differentiation markers, and can be distinguished from sarcomatoid carcinoma by lack of spindle cells. Including two new cases described herein, there have been 51 cases of prostate PGCC reported in the English literature. Clinical features shared by cases of prostate PGCC include poor prognosis, occurrence in older patients, and frequent association with prior therapy. Pathologic features common to cases of prostate PGCC include admixture with a high-grade conventional prostate carcinoma component and absent or reduced expression of prostate differentiation markers. More recent studies have begun to elucidate the molecular characteristics of PGCC, detecting specific mutations and chromosomal translocations, and showing evidence of a high degree of molecular instability in these tumors. We report novel findings in two cases of PGCC including a PIK3CA p.His1047Arg mutation not previously described. One of our cases is the first to clearly demonstrate chronological loss of prostate markers during dedifferentiation from prior conventional prostate carcinoma to PGCC. Herein, we present our two new cases and comprehensively review the literature on all reported cases of PGCC with critical commentary on findings in cases of this rare tumor.

Dietary Factors and Prostate Cancer Development, Progression, and Reduction

Due to the constantly increasing number of cases, prostate cancer has become one of the most important health problems of modern societies. This review presents the current knowledge regarding the role of nutrients and foodstuff consumption in the etiology and development of prostate malignancies, including the potential mechanisms of action. The results of several in vivo and in vitro laboratory experiments as well as those reported by the clinical and epidemiological research studies carried out around the world were analyzed. The outcomes of these studies clearly show the influence of both nutrients and food products on the etiology and prevention of prostate cancer. Consumption of certain nutrients (saturated and trans fatty acids) and food products (e.g., processed meat products) leads to the disruption of prostate hormonal regulation, induction of oxidative stress and inflammation, and alteration of growth factor signaling and lipid metabolism, which all contribute to prostate carcinogenesis. On the other hand, a high consumption of vegetables, fruits, fish, and whole grain products exerts protective and/or therapeutic effects. Special bioactive functions are assigned to compounds such as flavonoids, stilbenes, and lycopene. Since the influence of nutrients and dietary pattern is a modifiable risk factor in the development and prevention of prostate cancer, awareness of the beneficial and harmful effects of individual food ingredients is of great importance in the global strategy against prostate cancer.

Neuroendocrine cells of the prostate: Histology, biological functions, and molecular mechanisms

Prostate cancer (PCa) is a common cause of cancer-related mortality in men worldwide. Although most men are diagnosed with low grade, indolent tumors that are potentially curable, a significant subset develops advanced disease where hormone therapy is required to target the androgen receptor (AR). Despite its initial effect, hormone therapy eventually fails and the tumor progresses to lethal stages even through continued inhibition of AR. This review article focuses on the role of PCa cellular heterogeneity in therapy resistance and disease progression. Although AR-positive luminal-type cells represent the vast majority of PCa cells, there exists a minor component of AR-negative neuroendocrine (NE) cells that are resistant to hormonal therapy and are enriched by the treatment. In addition, it is now well accepted that a significant subset of hormonally treated tumors recur as small cell neuroendocrine carcinoma (SCNC), further highlighting the importance of targeting NE cells in addition to the more abundant luminal-type cancer cells. Although it has been long recognized that NE cells are present in PCa, their underlying function in benign prostate and molecular mechanisms contributing to PCa progression remains poorly understood. In this article, we review the morphology and function of NE cells in benign prostate and PCa as well as underlying molecular mechanisms. In addition, we review the major reported mechanisms for transformation from common adenocarcinoma histology to the highly lethal SCNC, a significant clinical challenge in the management of advanced PCa.

Ductal Prostate Cancers Demonstrate Poor Outcomes with Conventional Therapies

BACKGROUND

Ductal prostate adenocarcinoma (DAC) is a rare, aggressive, histologic variant of prostate cancer that is treated with conventional therapies, similar to high-risk prostate adenocarcinoma (PAC).

OBJECTIVE

To assess the outcomes of men undergoing definitive therapy for DAC or high-risk PAC and to explore the effects of androgen deprivation therapy (ADT) in improving the outcomes of DAC.

DESIGN, SETTING, AND PARTICIPANTS

A single-center retrospective review of all patients with cT1-4/N0-1 DAC from 2005 to 2018 was performed. Those undergoing radical prostatectomy (RP) or radiotherapy (RTx) for DAC were compared with cohorts of high-risk PAC patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Metastasis-free survival (MFS) and overall survival (OS) rates were analyzed using Kaplan-Meier and Cox regression models.

RESULTS AND LIMITATIONS

A total of 228 men with DAC were identified; 163 underwent RP, 34 underwent RTx, and 31 had neoadjuvant therapy prior to RP. In this study, 163 DAC patients and 155 PAC patients undergoing RP were compared. Similarly, 34 DAC patients and 74 PAC patients undergoing RTx were compared. DAC patients undergoing RP or RTx had worse 5-yr MFS (75% vs 95% and 62% vs 93%, respectively, p < 0.001) and 5-yr OS (88% vs 97% and 82% vs 100%, respectively, p < 0.05) compared with PAC patients. In the 76 men who received adjuvant/salvage ADT after RP, DAC also had worse MFS and OS than PAC (p < 0.01). A genomic analysis revealed that 10/11 (91%) DACs treated with ADT had intrinsic upregulation of androgen-resistant pathways. Further, none of the DAC patients (0/15) who received only neoadjuvant ADT prior to RP had any pathologic downgrading. The retrospective nature was a limitation.

CONCLUSIONS

Men undergoing RP or RTx for DAC had worse outcomes than PAC patients, regardless of the treatment modality. Upregulation of several intrinsic resistance pathways in DAC rendered ADT less effective. Further evaluation of the underlying biology of DAC with clinical trials is needed.

PATIENT SUMMARY

This study demonstrated worse outcomes among patients with ductal adenocarcinoma of the prostate than among high-grade prostate adenocarcinoma patients, regardless of the treatment modality.

Impact of treatment modality on overall survival in localized ductal prostate adenocarcinoma: A national cancer database analysis

PURPOSE

Ductal adenocarcinoma is considered a rare histological variant of prostate adenocarcinoma (PCa). Given the rarity of this subtype, optimal treatment strategies for men with nonmetastatic ductal PCa is largely unknown. We aimed to describe the impact of surgery, radiotherapy, systemic therapy, and observation on overall survival (OS) in men with nonmetastatic ductal PCa.

MATERIALS AND METHODS

We selected 1,656 cases of nonmetastatic ductal PCa, diagnosed between 2004 and 2015, within the National Cancer Database. Covariates included age, race, Charlson comorbidity score, clinical T stage, clinical lymph node stage, serum prostate specific antigen (PSA), income, hospital type, insurance status, year of diagnosis, and location of residence. Cox regression analysis tested the impact of treatment (surgery, radiotherapy, systemic therapy, and observation) on OS.

RESULTS

In men with nonmetastatic ductal PCa, median (interquartile range [IQR]) age and PSA were 67 (60-73) years and 6.2 (4.2-10.7) ng/ml, respectively. Advanced local stage (≥cT3a) was most frequently observed in patients initially treated with systemic therapy (34.8%), followed by those treated with radiotherapy (18.1%), surgery (7.1%) and observation (6.4%, P< 0.001). Serum PSA at presentation was highest in the systemic therapy cohort (median 16.0 ng/ml, IQR: 4.9-37.7), followed by the radiotherapy cohort (median 7.2 ng/ml, IQR: 4.1-12.2), observation cohort (median 7.0 ng/ml, IQR: 4.3-13.3) and surgery cohort (median 5.9 ng/ml, IQR: 4.3-9.2, P< 0.001). Multivariable analysis showed that in comparison to men treated surgically, OS was significantly lower for patients receiving radiotherapy (HR 2.2; 95% CI: 1.5-3.2), under observation (HR 4.6; 95% CI: 2.8-7.6) and receiving systemic therapy (HR 5.2; 95% CI: 3.0-9.1) as an initial course of treatment.

CONCLUSIONS

While limited by its retrospective nature, our study shows that starting treatment with surgery is associated with more favorable long-term OS outcomes than radiotherapy, systemic therapy or observation.

The assessment of a possible link between HPV-mediated inflammation, apoptosis, and angiogenesis in Prostate cancer

BACKGROUND

The aim of this study was to determine the presence of HPV in patients with Prostate cancer (PCa) and its possible association with cancer progression.

METHODS

In this case-control study, fresh prostate tissues and blood samples were collected from 90 individuals, including 58 cases samples with PCa and 32 non-malignant prostate tissue samples as a control group. The expression level of viral genes (E2, E6, and E7) and cellular factors including tumor suppressor proteins (Rb and p53), anti-apoptotic mediators (Bcl-2 and survivin), and some mediators involved in inflammation and angiogenesis was evaluated.

RESULTS

The presence of the HPV genome was identified in 19 out of the 58 cases (32.7%) and five out of the 32 controls (15.6%). However, there was not any statistically significant relationship between the presence of the HPV genome and PCa (OR = 2.63, 95% C.I = 0.89-7.91, P-value = 0.078). Moreover, the HPV high-risk genotypes 16 and 18 were detected in 47.4% and 31.6% of HPV-infected PCa tissues, respectively. The expression level of the tumor suppressor proteins (Rb and p53) significantly decreased in the HPV-infected samples compared to the HPV negative specimens (P-value = 0.01, P-value = 0.01, respectively). However, the expression level of the anti-apoptotic mediators and those involved in angiogenesis and inflammation significantly increased in the HPV-infected PCa group compared to the HPV-negative PCa and control groups (P-value < 0.05, respectively).

CONCLUSION

Our study suggests that although it is not definitely known whether HPV causes PCa, this virus probably modulates PCa cell behavior by affecting inflammation, angiogenesis, and apoptosis mechanisms, which, in turn, promotes tumorigenesis.

Uncommon Prostate Malignant Neoplasms

Prostate adenocarcinoma is the most common prostate cancer; however, there are several other malignant neoplasms that radiologists should be familiar with. The histological classification of malignant prostate neoplasms includes epithelial tumors, mesenchymal tumors, neuroendocrine tumors, hematolymphoid tumors, and stromal tumors. Knowledge of the main clinical and prostate magnetic resonance imaging features of uncommon tumors beyond adenocarcinoma is important for radiologists to enlarge their diagnostic ability and guide referring physician regarding the appropriate patient workup.The aim of this review article is to (1) review the main anatomical and histological concepts of the prostate gland and (2) provide an overview of uncommon prostate malignant neoplasms, emphasizing the key clinical, pathological, and imaging findings that may help radiologists in their daily interpretation of prostate magnetic resonance imaging.

Epidemiology of Signet Ring Cell Adenocarcinomas

Signet ring cell adenocarcinomas (SRCCs) are a rare histological subtype of adenocarcinomas with a poor prognosis, typically due to advanced disease at diagnosis. A signet ring cell, mimicking its moniker, contains abundant intracytoplasmic mucin that pushes the nucleus to the periphery. In these cancers, this cell feature comprises more than 50% of the tumor. Despite predilection for the gastrointestinal tract, and in particular the stomach, primary SRCCs are also described in other sites, typically in case reports. This literature, however, lacks a standardized overview of the SRCC disease entity. Using a retrospective cohort approach, we summarize the clinicodemographic and mortality outcomes of SRCCs in thirteen primary sites, comprising 95% of all SRCCs in the Surveillance, Epidemiology, and End Results Program (SEER), a population-level cancer database covering nearly one-third of the United States population. SRCCs general trends compared to matching nonvariant adenocarcinomas are earlier age of onset, with initial presentation favoring higher rates of regional or distant disease presentation and poor tumor differentiation. After multivariable analysis, SRCCs typically have worse overall survivals, but substantial variances exist depending on tumor location. Identifying SRCCs at earlier disease stages is likely the single most important intervention to improving outcomes for these patients.

Patterns of metastases of prostatic ductal adenocarcinoma

BACKGROUND

The current study was conducted to investigate the patterns of metastases in men with metastatic prostatic ductal adenocarcinoma (DAC) and recurrence patterns after therapy.

METHODS

All patients with a new diagnosis of DAC with de novo metastases and those with localized disease who developed metastases after treatment and were treated at the study institution from January 2005 to November 2018 were included. All patient and tumor characteristics and outcome data were collected.

RESULTS

A total of 164 patients (37.7%) had metastatic DAC, including 112 with de novo metastases and 52 who developed metastases after treatment. Men with de novo metastases were found to have a significantly higher median prostate-specific antigen level and International Society of Urological Pathology grade but a lower cT3 and/or T4 classification compared with those with metastases that developed after treatment (all P < .05). Approximately 87% of men with de novo metastases progressed despite multiple systemic therapies, 37.6% required intervention for the palliation of symptoms, and 10.1% responded to systemic therapy and underwent treatment of the primary tumor. Men with de novo metastatic DAC and those who developed metastases after treatment had multiple metastatic sites (including bone and viscera), with higher rates of lung metastases noted in the posttreatment group (23.2% vs 44.2%; P = .01). A total of 45 patients who were treated with curative intent developed metastases at a median of 22 months (range, 0.9-74.8 months) after treatment, at low prostate-specific antigen levels (median, 4.4 ng/mL [interquartile range, 1.7-11.1 ng/mL]).

CONCLUSIONS

The current study described the metastatic patterns of DAC in both patients with de novo metastatic disease and those who later progress to metastases. Men receiving treatment for DAC with curative intent require stringent long-term follow-up with imaging modalities, including chest imaging given the predilection toward lung metastases noted among these patients.

Significance of Paneth cell-like differentiation in prostatic adenocarcinoma: a retrospective cohort study of 80 cases

The grading and prognosis of prostatic adenocarcinoma with Paneth cell-like differentiation (PanEC) is controversial with limited available data. We identified 80 cases, not previously published, of PanEC first identified on biopsy (n = 69), transurethral resection of the prostate (n = 1), and radical prostatectomy (RP) (n = 10). Of 69 biopsies, 22 did not have a grade assigned. In the remaining 47 biopsies, the Grade Groups (GGs) of the associated usual prostatic adenocarcinoma were GG1-2 (n = 34) and GG3-5 (n = 13). Of 10 RPs, the GGs were as follows: GG1-2 (n = 8), GG4 (n = 1), and no grade due to treatment effect (n = 1); pathological stages were pT2 (n = 8) and pT3a (n = 2), all with negative lymph nodes. We analyzed 19 cases with available follow-up only associated with GG1-2 conventional cancer; 9 underwent RP, and GGs at RP were as follows: GG1-2 (n = 7), no grade due to treatment effect (n = 1), and missing data (n = 1); pathologic stages were pT2 (n = 6) and pT3a (n = 3); there were no positive regional lymph nodes; 3 were managed with active surveillance, without follow-up progression; 5 patients underwent radiation therapy with or without hormone therapy; none showed follow-up progression; 2 (10.5%) patients were recommended to undergo radiotherapy, with no further follow-up. Of the cases with available follow-up, 9 were not associated with conventional adenocarcinoma; the majority of these cases were treated with radiation therapy or active surveillance without evidence of progression. In summary, although a minority of PanECs are associated with conventional higher grade adenocarcinoma and have progression after treatment, the majority have favorable findings, justifying the consideration of them as more indolent tumors despite cases in which PanEC resembles Gleason pattern 5 adenocarcinoma.

Sequential Ras/MAPK and PI3K/AKT/mTOR pathways recruitment drives basal extrusion in the prostate-like gland of Drosophila

One of the most important but less understood step of epithelial tumourigenesis occurs when cells acquire the ability to leave their epithelial compartment. This phenomenon, described as basal epithelial cell extrusion (basal extrusion), represents the first step of tumour invasion. However, due to lack of adequate in vivo model, implication of emblematic signalling pathways such as Ras/Mitogen-Activated Protein Kinase (MAPK) and phosphoinositide 3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathways, is scarcely described in this phenomenon. We have developed a unique model of basal extrusion in the Drosophila accessory gland. There, we demonstrate that both Ras/MAPK and PI3K/AKT/mTOR pathways are necessary for basal extrusion. Furthermore, as in prostate cancer, we show that these pathways are co-activated. This occurs through set up of Epidermal Growth Factor Receptor (EGFR) and Insulin Receptor (InR) dependent autocrine loops, a phenomenon that, considering human data, could be relevant for prostate cancer.

The molecular mechanisms leading to basal extrusion are unclear. Here, the authors use the Drosophila accessory gland to model human prostate acini and show that Ras/MAPK and PI3K/AKT/mTOR pathways are co-activated in two autocrine loops by dEGF and dIGF, inducing basal extrusion and subsequent tumour formation.