Small Cell (Neuroendocrine) Carcinoma of the Prostate: Etiology, Diagnosis, Prognosis, and Therapeutic Implications—A Retrospective Study of 30 Patients From the Rare Cancer Network

PET/CT and Conventional Imaging for the Assessment of Neuroendocrine Prostate Cancer: A Systematic Review

BACKGROUND

Neuroendocrine prostate cancer (NEPC) is a rare neoplasm, and the role of both conventional imaging (CI) and positron emission tomography/computed tomography (PET/CT) for its assessment has not been clearly evaluated and demonstrated. The aim of this systematic review was to analyze the diagnostic performances of these imaging modalities in this setting.

METHODS

A wide literature search of the PubMed/MEDLINE, Scopus, and Web of Science databases was made to find relevant published articles about the role of CI and PET/CT for the evaluation of NEPC.

RESULTS

13 studies were included in the systematic review. PET/CT imaging with different radiopharmaceuticals has been evaluated in many studies (10) compared to CI (3 studies), which has only a limited role in NEPC. Focusing on PET/CT, a study used [18F]FDG, labeled somatostatin analogs were used in 5 cases, a study used [68Ga]Ga-FAPI-04, [68Ga]Ga-PSMA-11 was evaluated in a single case, and two works used different tracers.

CONCLUSION

Published data on the role of PET/CT for the assessment of NEPC are limited. At present, it is still uncertain which tracer performs best, and although [18F]FDG has been evaluated and seems to offer some advantages in availability and clinical staging, other tracers may be more useful to understand tumor biology or identify targets for subsequent radioligand therapy. Further research is therefore desirable. In contrast, data are still limited to draw a final conclusion on the role and the specific characteristics of CI in this rare form of neoplasm, and therefore, more studies are needed in this setting.

Managing a Rare Case of Mixed Extrapulmonary Small Cell Carcinoma and Adenocarcinoma of the Prostate

This report presents a remarkable and unusual case of extrapulmonary small cell carcinoma (EPSCC) occurring in the prostate of a 77-year-old male patient with a previous history of prostate adenocarcinoma and multiple metastases. EPSCC is a highly aggressive form of cancer that often results in unfavorable survival outcomes, posing significant challenges in terms of management due to the absence of established treatment protocols. Despite receiving standard treatment including bicalutamide and leuprorelin, the patient's condition showed no improvement. Consequently, the medical team made the decision to administer a carboplatin-etoposide chemotherapy regimen along with durvalumab, drawing upon the efficacy observed in similar treatment approaches for small cell carcinoma of the lung. This case highlights the critical need for further research and clinical trials to establish optimal treatment strategies for EPSCC affecting the prostate. By enhancing our understanding of this rare malignancy, we can potentially improve patient outcomes and develop targeted therapies tailored to its aggressive nature.

A Review of Prostate Organogenesis and a Role for iPSC-Derived Prostate Organoids to Study Prostate Development and Disease

The prostate is vulnerable to two major age-associated diseases, cancer and benign enlargement, which account for significant morbidity and mortality for men across the globe. Prostate cancer is the most common cancer reported in men, with over 1.2 million new cases diagnosed and 350,000 deaths recorded annually worldwide. Benign prostatic hyperplasia (BPH), characterised by the continuous enlargement of the adult prostate, symptomatically afflicts around 50% of men worldwide. A better understanding of the biological processes underpinning these diseases is needed to generate new treatment approaches. Developmental studies of the prostate have shed some light on the processes essential for prostate organogenesis, with many of these up- or downregulated genes expressions also observed in prostate cancer and/or BPH progression. These insights into human disease have been inferred through comparative biological studies relying primarily on rodent models. However, directly observing mechanisms of human prostate development has been more challenging due to limitations in accessing human foetal material. Induced pluripotent stem cells (iPSCs) could provide a suitable alternative as they can mimic embryonic cells, and iPSC-derived prostate organoids present a significant opportunity to study early human prostate developmental processes. In this review, we discuss the current understanding of prostate development and its relevance to prostate-associated diseases. Additionally, we detail the potential of iPSC-derived prostate organoids for studying human prostate development and disease.

The regulatory pathways leading to stem-like cells underlie prostate cancer progression

Prostate cancer (PCa) is the most common cause of malignancy in males and the third leading cause of cancer mortality in the United States. The standard care for primary PCa with local invasive disease mainly is surgery and radiation. For patients with distant metastases, androgen deprivation therapy (ADT) is a gold standard. Regardless of a favorable outcome of ADT, patients inevitably relapse to an end-stage castration-resistant prostate cancer (CRPC) leading to mortality. Therefore, revealing the mechanism and identifying cellular components driving aggressive PCa is critical for prognosis and therapeutic intervention. Cancer stem cell (CSC) phenotypes characterized as poor differentiation, cancer initiation with self-renewal capabilities, and therapeutic resistance are proposed to contribute to the onset of CRPC. In this review, we discuss the role of CSC in CRPC with the evidence of CSC phenotypes and the possible underlying mechanisms.

Complete metabolic response of metastatic castration-resistant neuroendocrine carcinoma of the prostate after treatment with RRx-001 and reintroduced platinum doublets

Presented herein is the case of a heavily pretreated patient with high-grade neuroendocrine prostate cancer that achieved a complete metabolic response on platinum-based chemotherapy after treatment with the dual CD-47 and SIRP-α inhibitor, RRx-001, in a Phase II clinical trial.

Small Cell Carcinoma of Prostate: A Case Report of a Patient With Concomitant Transitional Cell Cancer of the Bladder

Small cell carcinomas (SCCs) are aggressive neoplasms commonly associated with a pulmonary origin. However, albeit rare, extrapulmonary SCC can occur in a variety of sites with an incidence in North America approximated to be 0.1% to 0.4%. Among these sites, approximately 10% of extrapulmonary SCC cases occur in the prostate and are associated with a poor mortality with a median survival of 10 months. Because of the rarity of the prostatic SCC, there is no formal treatment protocol. In this case report, we present a patient who was diagnosed with SCC in the prostate as primary origin. Adjuvant concurrent chemoradiotherapy was started, which he is tolerating so far. While the management of metastatic disease is well documented with the use of chemotherapy, specific data on nonmetastatic disease is lacking. As some studies suggest, a combined surgical and chemotherapeutic approach is helpful in localized disease. In our case, this approach has led to a good clinical outcome in a disease that does not usually allow such results.

A Phase I/II Study of the Investigational Drug Alisertib in Combination With Abiraterone and Prednisone for Patients With Metastatic Castration-Resistant Prostate Cancer Progressing on Abiraterone

Lessons Learned

Patients with metastatic castration-resistant prostate cancer did not tolerate the combination of alisertib with abiraterone and prednisone.

There was no clear signal indicating that adding alisertib might be beneficial for those patients progressing on abiraterone.

Background.

We hypothesized that Aurora A kinase (AK) contributes to castrate resistance in prostate cancer (PCa) and that inhibiting AK with alisertib can resensitize PCa cells to androgen receptor (AR) inhibitor abiraterone.

Methods.

This was a phase I/II trial to determine the safety and efficacy of alisertib when given in combination with abiraterone plus prednisone (AP). Metastatic castration-resistant prostate cancer (mCRPC) patients were treated with dose escalation (alisertib at 30, 40, and 50 mg orally b.i.d., days 1–7 every 21 days) per standard 3+3 design.

Results.

Nine of 43 planned subjects were enrolled. The maximum tolerated dose (MTD) was not reached, and the dose-limiting toxicities (DLTs) included neutropenic fever (1 of 9), neutropenia (1 of 9), fatigue with memory impairment (1 of 9), and diarrhea/mucositis (1 of 9). No prostate-specific antigen (PSA) decrease or circulating tumor cell (CTC) changes were observed during the study. Pharmacodynamically, adding alisertib did not affect total testosterone or dehydroepiandrosterone (DHEA) levels. There was some change in neuroendocrine markers after therapy. Mean duration on study was 2.5 months. The trial was terminated early.

Conclusion.

A tolerable dose of alisertib in combination with AP in mCRPC was not established in this study. There was no clear signal indicating that alisertib might be beneficial for patients with mCRPC progressing on abiraterone.

[Management of neuroendocrine prostate carcinoma: Literature review]

Neuroendocrine prostate carcinoma is a rare entity causing both diagnostic and therapeutic issues. There are basically four histological forms (adenocarcinoma with neuroendocrine differentiation, carcinoid tumors, small cell neuroendocrine carcinomas, large cell neuroendocrine carcinomas), which can be pure or mixed associated with prostatic carcinoma. There is no consensus on the management or the prognosis of these various tumor subtypes. We conducted a literature review aiming to determine the potential therapeutic implications.

PCA3 and TMPRSS2-ERG gene fusions as diagnostic biomarkers for prostate cancer

The incidence of prostate cancer (PCa) is rising steadily among males in many countries. Serum prostate-specific antigen (PSA) is widely applied to clinical diagnosis and screening of PCa. However, the so-called grey area of PSA levels 4.0-10.0 ng/mL has a low specificity of 25-40% resulting in a high rate of negative biopsy and overtreatment. So in order to treat PCa patients in early stage, there is an urgent need for new biomarkers in PCa diagnosis. The PCA3 gene, a non-coding RNA (ncRNA) that is highly expressed in prostate cancer (PCa) cells, has been identified as a molecular biomarkers to detect PCa, of which PCA3 has already under clinical application. PCA3 is strongly overexpressed in malignant prostate tissue compared to benign or normal adjacent one. Newly, PCA3 is considered to be a promising biomarker in clinical diagnosis and targeted therapy. The diagnostic significance of PCA3, however, is awaiting further researches. Moreover, it has been demonstrated recently that TMPRSS2-ERG gene fusion is identified as the predominant genetic change in patients diagnosed with PCa. Recent study revealed that combination of the PCA3 and TMPRSS2-ERG gene fusion test optimizes PCa detection compared with that of single biomarker, which would lead to a considerable reduction of the number of prostate biopsies. In this review, we focused on the potential use of PCA3 and TMPRSS2-ERG gene fusion detection in the diagnosis of PCa.

Extrapulmonary small cell carcinoma: imaging features with radiologic-pathologic correlation

Extrapulmonary small cell carcinoma (EPSCC) refers to small cell carcinoma arising outside of the lungs. EPSCC extrapulmonary small cell carcinoma is a rare aggressive neoplasm, representing a minority of all small cell carcinomas. Despite its uncommon occurrence, EPSCC extrapulmonary small cell carcinoma has been described in nearly every organ, most commonly in the gastrointestinal and genitourinary systems. As such, it is important for radiologists to be aware of the entity. Although imaging is neither sensitive nor specific for EPSCC extrapulmonary small cell carcinoma , it plays an important role by helping exclude metastases from a primary pulmonary tumor, establish tumor staging, and assess response to therapy. EPSCC extrapulmonary small cell carcinoma is diagnosed by demonstrating pathologic features of small cell carcinoma in an extrapulmonary site. There are two ways to stage EPSCC extrapulmonary small cell carcinoma . One method uses the Veterans Administration Lung Study Group system developed for small cell lung cancer that allocates patients into limited or extensive disease categories. The second approach is the American Joint Committee on Cancer tumor-node-metastasis system applied to other tumor subtypes arising from the same organ. Because of its rare and varied manifestations, the most effective treatment for EPSCC extrapulmonary small cell carcinoma has not been established. Current management recommendations are derived from retrospective studies and single-institution experiences or are extrapolated from small cell lung cancer data. Regardless of therapy, overall survival rates are poor, with 5-year survival rates around 13%. To help radiologists increase their familiarity with EPSCC extrapulmonary small cell carcinoma , this article provides (a) a background for EPSCC extrapulmonary small cell carcinoma based on the literature and (b) a pictorial review of EPSCC extrapulmonary small cell carcinoma in multiple organs, with radiologic-pathologic correlation.

Genitourinary small cell malignancies: prostate and bladder

Small cell carcinoma is an aggressive malignancy often associated with dismal prognosis due to the presence of advanced disease. Small cell malignancies, initially described in the lung (small cell carcinoma of the lung), can occur in extrapulmonary sites, such as prostate (small cell carcinoma of the prostate) and bladder (small cell carcinoma of the bladder), with similar clinicopathologic outcomes. There has been a paradigm shift in the management of small cell carcinoma of the lung from initial surgical treatment to use of chemotherapy followed by local therapies. Such treatment modalities have been applied to small cell carcinoma of the prostate and the bladder, with promise in improving patient survival. Use of platinum-based combination chemotherapy followed by surgical resection and/or radiation offers the most benefit. Further investigation at the molecular level may offer targeted therapies earlier in the course of the disease.

Models of neuroendocrine prostate cancer

Prostate cancer remains the second leading cause of cancer death in men in the USA and most western countries. Prostatic acinar adenocarcinoma is the most commonly diagnosed form of prostate cancer. Small-cell neuroendocrine carcinoma is less frequently identified at the time of initial diagnosis, but this highly aggressive form of prostate cancer is increasingly observed in patients who have failed first- and second-line hormone therapy. Thus, developing and exploring models of neuroendocrine prostate cancer (NePC) are of increasing importance. This review examines the relevant xenograft tumor and genetically engineered mouse models of NePC, with the aim of addressing salient features and clinical relevance.

UK single centre experience of rare and atypical variant of castrate-resistant prostate cancer: Poorly differentiated neuroendocrine small-cell carcinoma

Background:

We report on the emergence of a rare and atypical variant of castrate-resistant prostate cancer (CRPC) that is characterised by transformation into poorly differentiated neuroendocrine small-cell carcinoma (NSCC). The existence of this variant was previously described in isolated case reports and small case-studies, but as yet there has been no UK series reported in the literature.

Methods:

Between January 2010 and January 2014, eight cases were presented in our local multi-disciplinary team meeting having a diagnosis of NSCC arising on a background of prostate cancer treated with androgen deprivation therapy. We performed a retrospective review of the clinical records of these patients, to identify the mode of presentation, diagnostic investigations, pathological characteristics, and subsequent treatment and survival outcomes.

Results:

The median patient age was 77 years (range, 68 – 84), with a median time interval of 25 months (range, 7 – 83) between the original diagnosis and subsequent transformation to NSCC. The median prostate-specific antigen (PSA) was 4 ng/ml, at presentation. Most patients presented with local progression, combined with high-volume and atypical sites of metastasis (e.g. brain, pancreas and penis). Patients developed a good initial response to platinum-based chemotherapy, but responses were short-lived and prognosis poor, with a median overall survival (OS) of 8 months.

Conclusion:

Prostate NSCC represents an atypical variant of CRPC with significant therapeutic and prognostic implications. Based on our observations, we have proposed a clinical algorithm for early diagnosis and appropriate management of these patients.

Mixed adenocarcinoma and neuroendocrine prostate cancer: a case report

Background

Neuroendocrine prostate cancer is rare but lethal. It is one of the most common extra pulmonary manifestations of small cell cancer.

Case presentation

Here we present a case report of a 53-year-old male who presents with a mixed adenocarcinoma and neuroendocrine prostate tumor on a background of previously normal prostate-specific antigen (PSA). His initial symptoms prior to diagnosis included decreased urine output and acute kidney injury (AKI).

Conclusion

Neuroendocrine tumor does not elevate the PSA level and hence is often a late finding with a poor prognosis. Special staining on histopathogy is required to reveal this diagnosis.

Clinicopathological analysis on small cell carcinoma of the prostate in chinese patients

Objective: To explore the clinical and pathological characteristics of small-cell carcinoma (SmCC) of the prostate and applicable treatment methods. Methods: We reported three cases of SmCC of the prostate diagnosed from 1999 to 2011 at the Chinese PLA General Hospital. We also reviewed clinical and pathological data of 26 cases in China reported over the same period. Results: Serum prostate-specific antigen (PSA) levels were normal in 20 cases (76.9%) and elevated in six (23.1%). There was local invasion in 12 cases (46.2%) at the time of diagnosis; lymphatic vessel invasion and distant metastases were detected in eight (30.8%) and nine cases (34.6%) respectively. At the end of follow-up, 16 cases (61.5%) had died, eight (30.8%) survived, and two (7.7%) were missing. The median survival time was 8 months, and the 1-year survival rate was 23.2%. Statistical analysis showed that survival time was significantly correlated with chemotherapy treatment (p<0.05). However, serum PSA levels, surgical approach, pathological type, local invasion, lymphatic vessel invasion, and distant metastasis had no significant relationship with survival (p>0.05). Conclusions: SmCC of the prostate is a rare neoplasm typified by high malignancy, rapid progress, and poor prognosis. Pathological analysis is an important tool for confirming a diagnosis. Pure SmCC is usually not associated with an increase in serum PSA. Surgery, mixed with acinar adenocarcinoma components, and clinical staging do not correlate with prognosis; and chemotherapy was the only prognostic factor. For patients, diagnosed by preoperative biopsy, administering chemotherapy as the first-line treatment may improve outcomes.

Small cell carcinoma of the prostate

Pure small-cell carcinoma (SCC) of the prostate is a rare entity and one of the most aggressive malignancies of the prostate. Histologically, prostatic SCCs of the prostate are part of a spectrum of anaplastic tumours of the prostate and are similar to SCCs of the lungs. In most cases, SCC of the prostate is associated with conventional prostatic adenocarcinoma. Both components of these mixed tumours frequently share molecular alterations such as ERG gene rearrangements or AURKA and MYCN amplifications, suggesting a common clonal origin. The clinical behaviour of small-cell prostate carcinomas is characterized by extensive local disease, visceral disease, and low PSA levels despite large metastatic burden. Commonly, the emergence of the SCC occurs in patients with high-grade adenocarcinoma who are often treated with androgen deprivation treatment (ADT). However, SCCs do not usually benefit from ADT. A biopsy of accessible lesions is strongly recommended to identify those with SCC pathological features, as management is undoubtedly affected by this finding. Chemotherapy is the standard approach for treating patients with either localized or advanced prostatic SCC. Despite the emergence of more-aggressive treatment modalities, the prognosis of men with prostatic SCC remains dismal.

Genitourinary small-cell carcinoma: a single-institution experience

BACKGROUND

Small-cell carcinomas (sccs) of the genitourinary (gu) tract are rare systemic diseases, and there is no standard treatment strategy for patients with this malignancy. The objectives of the present study were to report the management and outcome of patients with scc of the gu tract treated at a tertiary-care institution from 1982 to 2009.

METHODS

In a chart review of all patients diagnosed with scc of the gu tract between 1982 and 2009, data on demographics, clinical and pathologic characteristics, treatment, and patient outcomes were collected.

RESULTS

The 58 patients identified had scc in the following primary sites: urinary bladder (n = 35), prostate (n = 17), and upper urinary tract (n = 6). In 38 patients (66%), the scc was of pure histology; in the remainder, histology was mixed. Overall, 28 patients had limited-stage disease; 24 had extensive-stage disease; and staging was unknown in 6 patients. Median survival for the entire cohort was 7.5 months, with extensive-stage disease being identified as a poor prognostic factor (survival was 22.0 months for limited-stage patients and 4.1 months for extensive-stage patients, p < 0.001). Based on site, prostate patients fared worst, with a median survival of only 5.1 months. Compared with best supportive care, treatment was associated with better outcomes (median survival: 12.3 months vs. 2.3 months, p < 0.0001).

CONCLUSIONS

Small-cell cancer of the gu tract is an aggressive cancer, with a poor prognosis overall. Although there is no standard of care, patients should be treated using a multimodality approach analogous to that used in the treatment of small-cell lung cancer.

Prostatic stromal neoplasms: differential diagnosis of cystic and solid prostatic and periprostatic masses

OBJECTIVE

The objectives of this article are to illustrate the radiologic-pathologic correlation of prostate stromal neoplasms and to review the imaging appearances of cystic and solid prostatic and periprostatic masses that may mimic prostatic stromal neoplasms.

CONCLUSION

The differential diagnosis for cystic and solid masses in the prostate is broad, and masses arising from periprostatic structures may mimic the appearance of primary prostatic diseases. Attention to clinical and imaging features is helpful in narrowing the differential diagnosis.

Imaging features of extrapulmonary small cell carcinoma

Small cell carcinoma accounts for approximately 20% of lung cancers; however, it rarely occurs at other sites. Extrapulmonary small cell carcinoma (EPSCC) is notoriously aggressive with a strong propensity for both regional and distant spread. The majority of the literature on these uncommon tumours is from a clinicopathological viewpoint with a relative paucity of detail regarding the radiological findings. This review will focus on the imaging features of EPSCC in its predominant sites of origin: the gastrointestinal tract, genitourinary tract, head, neck, and breast. We will also discuss the role of positron-emission tomography (PET)/computed tomography (CT) in the staging of EPSCC.

The Rare Cancer Network: achievements from 1993 to 2012

The Rare Cancer Network (RCN), founded in 1993, performs research involving rare tumors that are not common enough to be the focus of prospective study. Over 55 studies have either been completed or are in progress.

The aim of the paper is to present an overview of the 30 studies done through the RCN to date, organized by disease site. Five studies focus on breast pathology, including sarcoma, lymphoma, phyllodes tumor, adenoid cystic carcinoma, and ductal carcinoma in situ in young women. Three studies on prostate cancer address prostatic small cell carcinoma and adenocarcinoma of young and elderly patients. Six studies on head and neck cancers include orbital and intraocular lymphoma, mucosal melanoma, pediatric nasopharyngeal carcinoma, olfactory neuroblastoma, and mucosa-associated lymphoid tissue lymphoma of the salivary glands. There were 4 central nervous system studies on patients with cerebellar glioblastoma multiforme, atypical and malignant meningioma, spinal epidural lymphoma and myxopapillary ependymoma. Outside of these disease sites, there is a wide variety of other studies on tumors ranging from uterine leiomyosarcoma to giant cell tumors of the bone. The studies done by the RCN represent a wide range of rare pathologies that were previously only studied in small series or case reports. With further growth of the RCN and collaboration between members our ability to analyze rare tumors will increase and result in better understanding of their behavior and ultimately help direct research that may improve patient outcomes.

Small cell carcinoma of the urinary bladder: a rare tumor with propensity for hepatic involvement

Small cell (neuroendocrine) carcinoma of the bladder is a rare entity, accounting for less than 1% of all bladder tumors. The authors report 2 new cases of the disease, both presenting with liver metastasis. In the first case, small cell carcinoma occurred in an 85-year-old woman as tumor recurrence of previous micropapillary carcinoma and urothelial carcinoma in situ, illustrating the common coexistence with conventional urothelial carcinoma. In the second case of a 58-year-old man, non-small cell tumor components were not observed. Accurate diagnosis of small cell carcinoma may be challenging. A panel of different antibodies, including neuron-specific enolase, chromogranin A, synaptophysin and CD56 (neural cell adhesion molecule) is recommended. In conclusion, small cell carcinoma represents a rare and aggressive form of bladder malignancy. As illustrated by the 2 cases and according to the literature review, the tumor shows a so far underrecognized propensity for hepatic involvement.

Prostatic carcinomas with neuroendocrine differentiation diagnosed in needle biopsies, a morphologic study of 7 cases among 465 sequential biopsies in a tertiary cancer center

PURPOSE

Neuroendocrine carcinomas (NEC) of the prostate are rare, with only a few series hitherto reported. The objective of this study was to assess in a single institution the clinical and morphologic characteristics of neuroendocrine carcinomas diagnosed in needle core biopsies.

MATERIALS AND METHODS

The current study analyses seven cases diagnosed in needle biopsies at a large tertiary regional cancer center from Northeastern Brazil. Two pathologists reviewed specimens retrospectively, and demographic and morphologic characteristics were compared to 458 acinar tumors diagnosed in the same period.

RESULTS

There were five small cell carcinomas and two low-grade neuroendocrine carcinomas (carcinoid). NEC were associated with an acinar component in 5/7 cases and the Gleason score of the acinar component was always > 6. The number of cores involved in prostates with NEC was greater (65% compared to 24% of acinar tumors, p < 0.05). The mean PSA at diagnosis was 417.7 (range 5.7-1593, SD 218.3), compared to 100.5 (p = 0.1) of acinar tumors (range 0.3-8545, SD 22.7). Prostates harboring NEC were bigger (p < 0.001, mean volume 240 mL vs. 53 mL of acinar tumors). Treatment of NEC included palliative surgery, chemotherapy, and hormonal therapy.

CONCLUSIONS

NEC of the prostate is rare and often associated with a high-grade acinar component. Prostates with NEC tend to be larger and involve a greater number of cores than acinar tumors. PSA at diagnosis does not seem to predict the presence of NE tumors in needle biopsy.

Extrapulmonary small cell carcinoma: a pictorial review

OBJECTIVE

Extrapulmonary small cell carcinoma (EPSCC) is a rare, aggressive neoplasm arising from virtually any organ. Numerous oncologic studies have addressed prognostic indicators and survival rates in EPSCC, however relatively little has been published regarding the imaging features and metastatic patterns of these uncommon tumors. This article provides a pictorial review of EPSCC in multiple organs, emphasizing the imaging appearance at presentation and the radiologic patterns of recurrence/metastasis.

CONCLUSION

Although the appearance of EPSCC is often nonspecific, the typical presentation is large aggressive tumors that, similar to small cell carcinoma in the lung, often respond well to local therapy but tend to recur relentlessly at distant sites.

A case of definitive therapy for localised prostate cancer: report of a urological nightmare

Radical prostatectomy, external beam radiotherapy and permanent brachytherapy are the most common treatment options for nonmetastatic localised adenocarcinoma of the prostate (PCa). Accurate pretherapeutic clinical staging is difficult, the number of positive cores after biopsy does not imperatively represent the extension of the cancer. Furthermore postoperative upgrading in Gleason score is frequently observed. Even in a localised setting a certain amount of patients with organ-confined PCa will develop biochemical progression. In case of a rise in PSA level after radiation the majority of patients will receive androgen deprivation therapy what must be considered as palliative. If local or systemic progressive disease is associated with evolving neuroendocrine differentiation hormonal manipulation is increasingly ineffective; radiotherapy and systemic chemotherapy with a platinum agent and etoposide are recommended. In case of local progression complications such as pelvic pain, gross haematuria, infravesical obstruction and rectal invasion with obstruction and consecutive ileus can possibly occur. In this situation palliative radical surgery is a therapy option especially in the absence of distant metastases. A case with local and later systemic progression after permanent brachytherapy is presented here.

Review of small cell carcinomas of the prostate

Small cell carcinoma of the prostate is a rare neoplasm, with only a few series hitherto reported. A little less than half of the cases are associated with conventional acinar adenocarcinoma, which are usually high grade. Although consensus has not been reached, the majority of patients with small cell neuroendocrine carcinoma of the prostate have advanced disease at diagnosis and disproportionally low PSA levels compared to patients with conventional acinar adenocarcinoma. Treatment consists mainly of chemotherapy associated with surgery. Radiation therapy is reserved for selected cases. This study reviews the most up-to-date information on small cell carcinomas of the prostate.

ERG-TMPRSS2 rearrangement is shared by concurrent prostatic adenocarcinoma and prostatic small cell carcinoma and absent in small cell carcinoma of the urinary bladder: evidence supporting monoclonal origin

Prostatic carcinoma is a heterogeneous disease with frequent multifocality and variability in morphology. Particularly, prostatic small cell carcinoma is a rare variant with aggressive behavior. Distinction between small cell carcinoma of the prostate and urinary bladder may be challenging, especially in small biopsy specimens without associated prostatic adenocarcinoma or urothelial carcinoma. Recently, gene fusions between ETS genes, particularly ETS-related gene (ERG), and transmembrane protease, serine 2 (TMPRSS2) have been identified as a frequent event in prostate cancer. Thus, molecular methods may be helpful in determining the primary site of small cell carcinoma. Thirty cases of prostatic small cell carcinoma from the authors' archives were studied, among which 13 had concurrent prostatic adenocarcinoma. Tricolor fluorescence in situ hybridization (FISH) was performed on formalin-fixed paraffin-embedded tissue sections with a probe cocktail for 3'/5' ERG and TMPRSS2. Cases of small cell carcinoma of the bladder and conventional prostatic adenocarcinoma (25 each) were also tested as controls. ERG gene alterations were found only in prostate malignancies and not in benign prostatic tissue or bladder small cell carcinoma. TMPRSS2-ERG gene fusion was found in 47% (14/30) of prostatic small cell carcinoma. Of cases with concurrent prostatic adenocarcinoma, 85% (11/13) had identical findings in both components. In 20% of rearranged cases, the ERG abnormality was associated with 5' ERG deletion. In 17% (5/30) of cases, gain of the 21q22 locus was present. Two cases showed discordant aberrations in the small cell carcinoma and adenocarcinoma, one with deletion of 5' ERG and one with gain of chromosome 21q, both in only the adenocarcinoma component. Small cell carcinoma of the prostate demonstrates TMPRSS2-ERG rearrangement with comparable frequency to prostatic adenocarcinoma. In cases with concurrent adenocarcinoma and small cell carcinoma, the majority showed identical abnormalities in both components, indicating a likely common clonal origin. Discordant alterations were present in rare cases, suggesting that acquisition of additional genetic changes in multifocal tumors may be responsible for disease progression to a more aggressive phenotype. TMPRSS2-ERG fusion is absent in bladder small cell carcinoma, supporting the utility of FISH in distinguishing prostate from bladder primary tumors and identifying metastatic small cell carcinoma of unknown origin.

ERG gene rearrangements are common in prostatic small cell carcinomas

Small cell carcinoma of the prostate is a rare subtype with an aggressive clinical course. Despite the frequent occurrence of ERG gene rearrangements in acinar carcinoma, the incidence of these rearrangements in prostatic small cell carcinoma is unclear. In addition, molecular markers to distinguish prostatic small cell carcinomas from lung and bladder small cell carcinomas may be clinically useful. We examined the occurrence of ERG gene rearrangements by fluorescence in situ hybridization in prostatic, bladder and lung small cell carcinomas. We also examined the expression of ERG, androgen receptor (AR) and NKX3-1 by immunohistochemistry in prostatic cases. Overall, 45% (10/22) of prostatic small cell carcinoma cases harbored ERG rearrangements, whereas no cases of bladder or lung small cell carcinomas showed ERG rearrangement (0/12 and 0/13, respectively). Of prostatic small cell carcinoma cases, 80% (8/10) showed ERG deletion and 20% (2/10) showed ERG translocation. In 83% (5/6) of prostatic small cell carcinoma cases in which a concurrent conventional prostatic acinar carcinoma component was available for analysis, there was concordance for the presence/absence of ERG gene rearrangement between the different subtypes. ERG, AR and NKX3-1 protein expression was detected in a minority of prostatic small cell carcinoma cases (23, 27 and 18%, respectively), while these markers were positive in the majority of concurrent acinar carcinoma cases (66, 83 and 83%, respectively). The presence of ERG rearrangements in nearly half of the prostatic small cell carcinomas is a similar rate of rearrangement to that found in prostatic acinar carcinomas. Furthermore, the high concordance rate of ERG rearrangement between the small cell and acinar components in a given patient supports a common origin for these two subtypes of prostate cancer. Finally, the absence of ERG rearrangement in bladder or lung small cell carcinomas highlights the utility of detecting ERG rearrangement in small cell carcinomas of unknown primary for establishing prostatic origin.

Use of irinotecan for treatment of small cell carcinoma of the prostate

BACKGROUND

Prostatic small cell carcinoma (SCC) is a rare variant of prostate cancer. It is extremely aggressive and resistant to available therapies with a median survival range of 5-17 months. No standard chemotherapeutic regimen has been established for its treatment. In search of a new therapeutic approach, we examined the response of patient-derived prostatic SCC tissue xenografts to irinotecan, a topoisomerase I inhibitor.

METHODS

A tumor tissue line was established from a patient's prostatic SCC by subrenal capsule grafting using NOD-SCID mice. Mice carrying subcutaneous transplants of the tumor line were then treated for 2 weeks with irinotecan alone and in combination with cisplatin. The effect on tumor volume, histopathology, and apoptosis were determined.

RESULTS

The prostatic SCC tissue line resembled the donor tissue in morphologic and immunohistochemical features. Irinotecan (20 mg/kg/day; days 1-3, 8-10) completely arrested xenograft growth with a small reduction in tumor volume and only minor weight loss of the hosts (7%); irinotecan (12 mg/kg; same schedule) + cisplatin (2.5 mg/kg/day; days 1 and 8) had a similar effect, but with lower weight loss. While the growth inhibition involved apoptosis, it was also associated with a marked increase in autophagy.

CONCLUSIONS

Tumor tissue lines established via subrenal capsule xenografting provide models with clinical relevance and the present study suggests that irinotecan could be useful for therapy of refractory prostatic SCC, in particular in combination with cisplatin.

Complete remission in a patient with metastatic mixed adenocarcinoma/extrapulmonary small cell carcinoma of the prostate

Approximately 10% of all extra-pulmonary small cell carcinoma (EPSCC) arises in the prostate either as de novo mixed adenocarcinoma with small cell components or a pure small cell carcinoma. Extensive disease carries a median survival of about 10 months in retrospective studies. We present a case managed aggressively with concomitant hormonal and chemotherapy, now 36 months without evidence of disease. At a routine physical, a 55 year male was found to have a 5 cm left upper lobe lung mass, invading his 3rd rib. An FNA revealed an adenocarcinoma of unknown primary. His PSA was elevated to 8 ng/mL and a prostate biopsy revealed Gleason 9 adenocarcinoma with neuro-endocrine/SCC components. A bone scan revealed extensive bone metastasis. He was managed aggressively with concomitant cisplatin, etoposide and hormonal therapy and received 73 Gy of radiation to the prostate. PET scans demonstrated marked response to chemotherapy. PSA and chromogrannin levels down trended to normal limits. His most recent PET scan in July 2010 revealed no evidence of disease and is in remission. We present a unique case of metastatic mixed adenocarcinoma/SCC of the prostate, in which the patient survived more than 36 months with complete remission after initiation of aggressive hormonal and chemotherapy. Data on survival in this patient population is limited to case reports, and ordinarily carries a poor prognosis of less than 1 year. In patients with clinical and pathologic features of mixed disease, initiation of early multi-modal therapy is warranted. Additionally, it may be of prognostic significance to biopsy any metastatic lesion.

Pure small cell carcinoma of the prostate: a case report and literature review

Primary small cell carcinoma of the prostate (SCPCa) is a rare pathologic entity with unique clinical features and a poor prognosis. We present a case of a patient diagnosed with pure SCPCa treated with a combined chemo-radiotherapeutic approach. Pathological findings showed that the neoplastic cells exhibited positivity for pancytokeratin, synaptophysin, thyroid transcription factor-1 and CD56. Immunostaining for prostate-specific antigen was negative, while serum prostate-specific antigen was within normal limits. We review the available literature to gain additional information about diagnosis, treatment and prognosis of pure SCPCa.

TMPRSS2-ERG gene fusion in small cell carcinoma of the prostate

Recent studies have shown that most prostate cancers carry the TMPRSS2-ERG gene fusion. Here we evaluated the TMPRSS2-ERG gene fusion in small cell carcinoma of the prostate (n = 12) in comparison with small cell carcinoma of the urinary bladder (n = 12) and lung (n = 11). Fluorescence in situ hybridization demonstrated rearrangement of the ERG gene in 8 cases of prostatic small cell carcinoma (67%), and the rearrangement was associated with deletion of the 5' ERG gene in 7 cases, but rearrangement of the ERG gene was not present in any small cell carcinoma of the urinary bladder or lung. Next we evaluated the TMPRSS2-ERG gene fusion in nude mouse xenografts that were derived from 2 prostatic small cell carcinomas carrying the TMPRSS2-ERG gene fusion. Two transcripts encoded by the TMPRSS2-ERG gene fusion were detected by reverse transcriptase polymerase chain reaction, and DNA sequencing demonstrated that the 2 transcripts were composed of fusions of exon 1 of the TMPRSS2 gene to exon 4 or 5 of the ERG gene. Our study demonstrates the specific presence of TMPRSS2-ERG gene fusion in prostatic small cell carcinoma, which may be helpful in distinguishing small cell carcinoma of prostatic origin from nonprostatic origins. The high prevalence of the TMPRSS2-ERG gene fusion in prostatic small cell carcinoma as well as adenocarcinoma implies that small cell carcinoma may share a common pathogenic pathway with adenocarcinoma in the prostate.

ERG rearrangement in small cell prostatic and lung cancer

AIMS

Small cell prostatic cancer is a rare but aggressive disease. Currently, its histogenetic origin is unclear and its distinction from metastatic small cell lung cancer is challenging. The aim of our study was to determine whether the ERG rearrangement commonly observed in acinar prostatic cancer can distinguish small cell prostatic cancer from small cell lung cancer samples.

METHODS AND RESULTS

We assessed 15 small cell prostatic cancers and 22 small cell lung cancers for ERG rearrangement using fluorescence in situ hybridization. Commonly used and novel immunohistochemical markers (i.e. androgen receptor, calcium activated nucleotidase 1, Golgi phosphoprotein 2, prostate-specific antigen, prostate-specific membrane antigen, CD56, epithelial membrane antigen, thyroid transcription factor 1, chromogranin A, synaptophysin and Ki67) were further studied. ERG rearrangement occurred in 86% of small cell prostatic cancers but in none of the small cell lung cancers and was the best marker to differentiate between both tumours (P < 0.0001).

CONCLUSIONS

The ERG rearrangement is commonly observed in small cell prostatic cancer, supporting the hypothesis that ERG rearrangement occurs in aggressive prostatic cancers. Furthermore, the ERG rearrangement is the most significant marker to differentiate between small cell prostatic cancer and small cell lung cancer. Moreover, our data suggest that small cell prostatic cancer is not a tumour entity on its own, but a dedifferentiated variant of common acinar prostatic cancer.

Neuroendocrine carcinoma in a patient with Birt-Hogg-Dubé syndrome

BACKGROUND

A patient with Birt-Hogg-Dubé syndrome (BHD) presented with gross hematuria of 6 months' duration. Imaging revealed the presence of a mass in the left prostatic lobe, in addition to a previously observed renal mass. Prostate biopsy and imaging findings indicated an inflammatory etiology, and the patient was discharged. 5 months later, the patient presented once again with urinary retention. During transurethral resection of the prostate, a mass adjacent to the bladder was observed. Postoperative imaging revealed a large pelvic mass, a second mass impinging on the rectum, and extensive lymphadenopathy. The patient died 2 weeks later.

INVESTIGATIONS

CT and MRI, physical examination, measurement of serum markers, urinalysis, transrectal prostate biopsy, histopathological and genetic examination of tumor specimens, postmortem immunohistochemical analysis.

DIAGNOSIS

Neuroendocrine carcinoma of prostate or bladder origin.

MANAGEMENT

The patient died before planned chemotherapy or radiation therapy could be implemented. More-frequent monitoring of the patient might have led to earlier diagnosis and allowed treatment to be started before widespread tumor metastasis and invasion.

The relationship of neuroendocrine carcinomas to anti-tumor therapies in TRAMP mice

BACKGROUND

Neuroendocrine differentiation and neuroendocrine carcinoma (NEC) have been linked to androgen deprivation in prostate cancers. No previous study has directly connected neuroendocrine phenotypes to chemotherapy. The pathogenesis of prostatic NEC has not yet been determined.

METHODS

Using the transgenic adenocarcinoma of mouse prostate (TRAMP) model, we studied tumor progression after hormone ablation (castration) and/or chemotherapy (docetaxel), and analyzed the incidence of NEC as a function of the anti-tumor therapies. Non-treated mice were used as controls. Protein expressions in tumor tissues were analyzed by Western blots and immunohistochemistry.

RESULTS

Although all animals developed prostate cancer, no NEC was found in control mice. However, over 30% of the mice that received an anti-tumor therapy developed NEC. A similar incidence of NEC was found in the castration-only and docetaxel-only treatment groups, while a higher incidence was observed in the combined treatment (castration and docetaxel) group. The NEC-bearing mice had smaller tumors in their prostates and lived longer than mice with adenocarcinoma (ADC-only). However, NEC tumors had a higher proliferative index and greater potential for metastasis and drug-resistance, as evidenced by significantly higher expression levels of PCNA, S100A4, and Pgp, but lower levels of E-cadherin. SV40 T-antigen was highly expressed in both NEC and ADC tumors.

CONCLUSIONS

Stress induced by anti-cancer treatments may play a role in NEC development. Although NEC and ADC differ in their expressions of many proteins, a high level of SV40 T-antigen in both tumor types suggest a common progenitor..