Neuroendocrine Cancer of the Prostate

Development and Characterisation of a New Patient-Derived Xenograft Model of AR-Negative Metastatic Castration-Resistant Prostate Cancer

As the treatment landscape for prostate cancer gradually evolves, the frequency of treatment-induced neuroendocrine prostate cancer (NEPC) and double-negative prostate cancer (DNPC) that is deficient for androgen receptor (AR) and neuroendocrine (NE) markers has increased. These prostate cancer subtypes are typically refractory to AR-directed therapies and exhibit poor clinical outcomes. Only a small range of NEPC/DNPC models exist, limiting our molecular understanding of this disease and hindering our ability to perform preclinical trials exploring novel therapies to treat NEPC/DNPC that are urgently needed in the clinic. Here, we report the development of the CU-PC01 PDX model that represents AR-negative mCRPC with PTEN/RB/PSMA loss and CTNN1B/TP53/BRCA2 genetic variants. The CU-PC01 model lacks classic NE markers, with only focal and/or weak expression of chromogranin A, INSM1 and CD56. Collectively, these findings are most consistent with a DNPC phenotype. Ex vivo and in vivo preclinical studies revealed that CU-PC01 PDX tumours are resistant to mCRPC standard-of-care treatments enzalutamide and docetaxel, mirroring the donor patient's treatment response. Furthermore, short-term CU-PC01 tumour explant cultures indicate this model is initially sensitive to PARP inhibition with olaparib. Thus, the CU-PC01 PDX model provides a valuable opportunity to study AR-negative mCRPC biology and to discover new treatment avenues for this hard-to-treat disease.

Malignant glomus tumor of prostate: A case report

We reported an 85-year-old patient with malignant glomus tumor (GT) of the prostate. He presented with urinary frequency for more than 2 years and gross hematuria for 7 days. Computed tomography scan showed that the prostate was markedly irregularly enlarged, and the boundary between the prostate and the posterior wall of the bladder was unclear. Bilateral kidneys and ureters were dilated. Biochemical examinations showed that the serum potassium was 7.24 mmol/L and the serum creatinine was 974.6 μmol/L. Transurethral diagnostic resection was performed after restoring homeostasis through several times of bedside blood filtration. The pathological diagnosis was malignant GT. The patient's renal function recovered after bilateral nephrostomy, and he refused further treatment and was out of contact after 9 months. We summarize the clinical and histopathological features of malignant GT of the prostate in order to improve the early recognition of the disease by clinicians.

A rare case of prostate neuroendocrine tumor: A case report

Small cell prostate neuroendocrine carcinoma (SCPC) is a rare and highly aggressive malignant tumor. We present a case of a 52-year-old Iranian man, presenting with complaints of occasional gross hematuria and perineal pain for 6 months. PSA was 0.8 ng/ml. A digital rectal examination found a huge and hard prostate mass. He underwent a transrectal ultrasound-guided (TRUS) biopsy of the prostate. Histopathology showed high-grade small cell neuroendocrine carcinoma. Immunohistochemical markers were positive for synaptophysin with a Ki67 index of almost 100%. However, CD56 and chromogranin A markers were negative. Magnetic resonance imaging (MRI) of the prostate showed a prostate mass with invasion to the rectum, while contrast-enhanced computed tomography of the thorax, abdomen, and pelvis (CT TAP) ruled out metastasis. A multidisciplinary team discussion was carried out, and a decision was made for concurrent chemotherapy and radiation (cisplatin and etoposide for 4 cycles and 70 Gy, 35 fractions). There is a lack of consensus on the management of SCPC. The main modality of management in advanced (stage IV) disease is chemotherapy. It is a highly aggressive tumor with a poor prognosis and is not responsive to hormonal therapy.

Immunotherapy of Neuroendocrine Neoplasms: Any Role for the Chimeric Antigen Receptor T Cells?

Simple Summary

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of tumors arising in different organs whose clinical course is variable according to histological differentiation and metastatic spread. Therapeutic options have recently expanded, but there is a need for new effective therapies, especially in less differentiated forms. Chimeric antigen receptor T cells (CAR-T) have shown efficacy in several cancers, mainly hematological, but data on NENs are scattered. We aimed to analyze the available preclinical and clinical data about CAR-T in NENs, to highlight their potential role in clinical practice. A significant therapeutic effect of CAR-T cells in NENs emerges from preclinical studies. Results from clinical trials are expected in order to define their effective role in these cancers.

Abstract

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with variable clinical presentation and prognosis. Surgery, when feasible, is the most effective and often curative treatment. However, NENs are frequently locally advanced or already metastatic at diagnosis. Consequently, additional local or systemic therapeutic approaches are required. Immunotherapy, based on chimeric antigen receptor T cells (CAR-T), is showing impressive results in several cancer treatments. The aim of this narrative review is to analyze the available data about the use of CAR-T in NENs, including studies in both preclinical and clinical settings. We performed an extensive search for relevant data sources, comprising full-published articles, abstracts from international meetings, and worldwide registered clinical trials. Preclinical studies performed on both cell lines and animal models indicate a significant therapeutic effect of CAR-T cells in NENs. Ongoing and future clinical trials will clarify the possible role of these drugs in patients with highly aggressive NENs.

A first case of ductal adenocarcinoma of the prostate having characteristics of neuroendocrine phenotype with PTEN, RB1 and TP53 alterations

BACKGROUND

Ductal adenocarcinoma and neuroendocrine cancer are rare subtypes of prostate cancer with poor prognosis and limited therapeutic options. We present the first case of ductal adenocarcinoma having a neuroendocrine phenotype.

CASE PRESENTATION

A 63-year-old man presented with gross hematuria and urinary retention, and his serum prostate-specific antigen level was 4.58 ng/mL. We performed transurethral resection of the prostate, and the diagnosis was ductal adenocarcinoma with a Gleason score of 5 + 4 for acinar adenocarcinoma. Magnetic resonance imaging showed local invasion of left lobe of the prostate and bone metastasis of the left trochanteric section of the femur. Multidisciplinary treatments such as androgen deprivation therapy, chemoradiation therapy, and surgery for metastatic lesions have led to long-term survival. Since next-generation sequencing revealed PTEN and RB1 co-loss and TP53 mutations, we re-evaluated the immunohistochemistry and he was found to be positive for synaptophysin.

CONCLUSIONS

This is the first Japanese case of ductal adenocarcinoma with a neuroendocrine phenotype. Genetic analysis may help not only guide the therapeutic strategies, but also sometimes with the diagnosis.

Clinicopathological characteristics and survival outcomes in neuroendocrine prostate cancer: A population-based study

OBJECTIVE

This study aimed to investigate the clinicopathological features and the survival outcomes of neuroendocrine prostate cancer (NEPC).

METHODS

Within the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute, we identified a total of 510 patients with NEPC between 2006 and 2015. Age-adjusted incidence rates were evaluated in the study by the SEER∗Stat Software version 8.3.6. Kaplan-Meier analysed assessed overall survival (OS) after stratification according to marital status, age, histologic subtype, metastatic status, and treatment. The significant differences were assessed in a log-rank test. Univariate and multivariate cox hazard regression analysis were performed to determine independent predictors of OS.

RESULTS

From a total of 560,124 patients with prostate cancer diagnosed between 2006 and 2015, we identified 510 cases of de novo NEPC. Regarding histology, among all the NEPC, 329 (64.5%) patients were diagnosed as small cell carcinoma, 181 (39.8%) were nonsmall cell carcinoma. The overall age-adjusted incidence of NEPC statistically significantly increased from 0.321/1,000,000 person-years in 2006 to 0.587/1,000,000 person-years in 2015. The median OS in our study cohort was 9 months (95% CI, 8-10 months). Multivariate cox regression analysis showed that age, histologic subtype, and stage were independent prognostic factors for NEPC patients. The majority of NEPC (78.2%) were metastatic at diagnosis. In terms of treatment, for metastatic tumor patients, chemotherapy was the most effective therapy. Chemotherapy increased the OS of patients with regional (distant) metastases from 8 months (5 months) to 13.5 months (9 months).

CONCLUSION

NEPC is extremely rare but the incidence of NEPC has been increasing in the past years. The prognosis of NEPC is poor because most cases are diagnosed at metastatic stage. The patients with metastases are typically treated with chemotherapy and chemotherapy shows survival benefits in both regional and distant metastatic tumor patients.

MicroRNAs in treatment-induced neuroendocrine differentiation in prostate cancer

Prostate cancer is a condition commonly associated with men worldwide. Androgen deprivation therapy remains one of the targeted therapies. However, after some years, there is biochemical recurrence and metastatic progression into castration-resistant prostate cancer (CRPC). CRPC cases are treated with second-line androgen deprivation therapy, after which, these CRPCs transdifferentiate to form neuroendocrine prostate cancer (NEPC), a highly aggressive variant of CRPC. NEPC arises via a reversible transdifferentiation process, known as neuroendocrine differentiation (NED), which is associated with altered expression of lineage markers such as decreased expression of androgen receptor and increased expression of neuroendocrine lineage markers including enolase 2, chromogranin A and synaptophysin. The etiological factors and molecular basis for NED are poorly understood, contributing to a lack of adequate molecular biomarkers for its diagnosis and therapy. Therefore, there is a need to fully understand the underlying molecular basis for this cancer. Recent studies have shown that microRNAs (miRNAs) play a key epigenetic role in driving therapy-induced NED in prostate cancer. In this review, we briefly describe the role of miRNAs in prostate cancer and CRPCs, discuss some key players in NEPCs and elaborate on miRNA dysregulation as a key epigenetic process that accompanies therapy-induced NED in metastatic CRPC. This understanding will contribute to better clinical management of the disease.