Prostate Cancer Central Nervous System Metastasis in a Contemporary Cohort

PSMA PET improves characterization of dural-based intracranial lesions in patients with metastatic prostate cancer

PURPOSE

Theranostic approaches combining prostate-specific membrane antigen (PSMA)-PET/CT or PET/MRI with PSMA-targeted radionuclide therapy have improved clinical outcomes in patients with prostate cancer (PCa) especially metastatic castrate resistant prostate cancer. Dural metastases in PCa are rare but can pose a diagnostic challenge, as meningiomas, a more common dural based lesions have been shown to express PSMA. The aim of this study is to compare PSMA PET parameters between brain lesions classified as dural metastases and meningiomas in prostate cancer patients.

METHODS

A retrospective analysis of PSMA PET/CT scans in patients with PCa and intracranial lesions was conducted. Brain lesions were categorized as dural metastases or meningiomas based on MRI characteristics, longitudinal follow-up, and histopathological characteristics. Standardized uptake values (SUVmax) of each brain lesion were measured, along with SUV ratio referencing parotid gland (SUVR). SUVs between lesions classified as metastases and meningiomas, respectively, were compared using Mann-Whitney-test. Diagnostic accuracy was evaluated using ROC analysis.

RESULTS

26 male patients (median age: 76.5 years, range: 59-96 years) met inclusion criteria. A total of 44 lesions (7 meningiomas and 37 metastases) were analyzed. Median SUVmax and SUVR were significantly lower in meningiomas compared to metastases (SUVmax: 2.7 vs. 11.5, p = 0.001; SUVR: 0.26 vs. 1.05, p < 0.001). ROC analysis demonstrated AUC 0.903; the optimal cut-off value for SUVR was 0.81 with 81.1 % sensitivity and 100 % specificity.

CONCLUSION

PSMA PET has the potential to differentiate meningiomas from dural-based metastases in patients with PCa, which can optimize clinical management and thus improve patient outcomes.

Traditional Prostate Cancer Risk Assessment Scales Do Not Predict Outcomes from Brain Metastases: A Population-Based Predictive Nomogram

Brain metastases are an uncommon yet life-limiting manifestation of prostate cancer. However, there is limited insight into the natural progression, therapeutics, and patient outcomes for prostate cancer once metastasized to the brain. This is a retrospective study of 461 patients with metastatic prostate cancer to the brain with a primary outcome of median overall survival (OS). The Surveillance, Epidemiology, and End Results (SEER) database was examined using Cox regression univariate and multivariable analyses, and a corresponding nomogram was developed. The median overall survival was 15 months. In the multivariable analysis, Hispanic patients had significantly increased OS (median OS 17 months, p = 0.005). Patients with tumor sizes greater than three centimeters exhibited significantly reduced OS (median OS 19 months, p = 0.014). Patients with additional metastases to the liver exhibited significantly reduced OS (median OS 3.5 months, p < 0.001). Increased survival was demonstrated in patients treated with chemotherapy or systemic treatment (median OS 19 months, p = 0.039), in addition to radiation and chemotherapy (median OS 25 months, p = 0.002). The nomogram had a C-index of 0.641. For patients with prostate metastases to the brain, median OS is influenced by race, tumor size, presence of additional metastases, and treatment. The lack of an association between traditional prostate cancer prognosis metrics, including Gleason and ISUP grading, and mortality highlights the need for individualized, metastasis-specific prognosis metrics. This prognostic nomogram for prostate metastases to the brain can be used to guide the management of affected patients.

Preclinical evidence for the use of anti-Trop-2 antibody-drug conjugate Sacituzumab govitecan in cerebral metastasized castration-resistant prostate cancer

PURPOSE

Improved survival rates have been observed in castration-resistant prostate cancer (CRPC) due to advancements in treatment options. However, individuals with brain metastases still have limited therapeutic options and an unfavorable prognosis. Therefore, there is an urgent need to explore new therapeutic avenues, such as antibody-drug conjugates (ADCs), which have demonstrated significant clinical activity against active brain metastases in solid tumors. Our objective was to determine the expression levels of the ADC targets Trop-2 and NECTIN-4 in cerebral metastasized CRPC (mCRPC).

METHODS

Immunohistochemical staining of Trop-2 and NECTIN-4 with evaluation of H-score was performed in CRPC brain metastases (n = 31). Additionally, we examined Trop-2 protein expression in prostate cancer cell lines and studied their responsiveness to the anti-Trop-2 ADC Sacituzumab govitecan (SG) in vitro.

RESULTS

Our analysis revealed that most patients exhibited moderate to strong Trop-2 expression [n = 27/31 with H-score ≥100, median H-score 220 (IQR 180-280)], while NECTIN-4 was absent in all cerebral metastases. Mechanistically, we demonstrated that the efficacy of SG depends on Trop-2 expression levels in vitro. Overexpression of Trop-2 in Trop-2-negative PC-3 cells led to sensitization to SG, whereas CRISPR-Cas9-mediated knockdown of Trop-2 in Trop-2-expressing DU-145 cells conferred resistance to SG.

CONCLUSION

The substantial expression of Trop-2 in cerebral metastases, along with our preclinical in vitro results, supports the efficacy of SG in treating cerebral mCRPC. Thus, our results extend the understanding of the potential of ADCs in prostate cancer treatment and provide an additional treatment strategy for the challenging subset of patients with cerebral metastases.

Mechanosensitive Ion Channels: Their Physiological Importance and Potential Key Role in Cancer

Mechanosensitive ion channels comprise a broad group of proteins that sense mechanical extracellular and intracellular changes, translating them into cation influx to adapt and respond to these physical cues. All cells in the organism are mechanosensitive, and these physical cues have proven to have an important role in regulating proliferation, cell fate and differentiation, migration and cellular stress, among other processes. Indeed, the mechanical properties of the extracellular matrix in cancer change drastically due to high cell proliferation and modification of extracellular protein secretion, suggesting an important contribution to tumor cell regulation. In this review, we describe the physiological significance of mechanosensitive ion channels, emphasizing their role in cancer and immunity, and providing compelling proof of the importance of continuing to explore their potential as new therapeutic targets in cancer research.

The Successful Treatment of a Case of Prostate Cancer With Brain Metastasis at Diagnosis

Brain metastasis in prostate cancer is quite a rare entity, especially when it manifests at diagnosis. The symptoms are usually non-focal and vary based on the location affected. It is almost always associated with a poor prognosis, with an overall survival of less than a year. The ideal management modality for these patients is not well established but a combination of surgery, radiation, and chemotherapy may be possible options based on the extent and systemic involvement. Brain screening is not done systematically in prostate cancer and more research is needed to understand the outcome this decision would lead to. We report a case of a patient diagnosed with prostate cancer with single metastasis to the brain that manifested as headache and vomiting. The patient was treated with surgery, adjuvant irradiation of the surgical bed, and androgen deprivation therapy. He later underwent intensity-modulated radiation therapy (IMRT) to the prostate and has been remarkably relapse-free for four years.

Clinical and Genetic Analysis of Metastatic Prostate Cancer to the Central Nervous System: A Single-Institution Retrospective Experience

BACKGROUND

Prostate cancer (PC) rarely metastasizes to the central nervous system (CNS). In this retrospective single-institution study at a tertiary cancer center, we aimed to evaluate the clinical and genetic characteristics of advanced PC patients with CNS metastases.

PATIENTS AND METHODS

Between January 2010 and March 2020, 12 out of 579 patients with extracranial metastatic PC were identified to have CNS metastases based on imaging, including six patients with brain metastases (BMs), five patients with dural metastases, and one unknown. These patients were followed up through March 2022. Clinical data were compared to the overall cohort of patients evaluated at our cancer center during that decade. Genetics information was also analyzed for the patients with available data via cell-free DNA (cfDNA) blood samples.

RESULTS

Median time from development of extracranial metastatic disease to development of CNS metastases was 5.5 years (95% CI, 1.8-7.0). Median overall survival (mOS) from diagnosis of CNS metastases was 6.1 months (95% CI, 5.8-8.2). Notably, there was no significant difference in mOS after development of extracranial metastases in patients with CNS metastases (6.4 years; 95% CI, 4.6-7.9) compared to the patients without known CNS metastases (5.2 years; 95% CI, 4.6-5.7) (P = .91). For the cohort with CNS metastases, nine patients had germline testing and seven patients had somatic testing via cfDNA.

CONCLUSION

PC patients with CNS metastases did not often die from a neurological cause. With advancing therapies, the overall prognosis of metastatic PC continues to improve, and CNS metastases will become more common.

The Clinical, Diagnostic, Therapeutic, and Prognostic Characteristics of Brain Metastases in Prostate Cancer: A Systematic Review

AIM

Prostate cancer (PCa) is the second most common nonskin malignancy and the second most common cause of cancer-related deaths in men. The most common site of metastasis in PCa is the axial skeleton which may lead to back pain or pathological fractures. Hematogenous spread to the brain and involvement of the central nervous system (CNS) are a rare occurrence. However, failed androgen deprivation therapy (ADT) may facilitate such a spread resulting in an advanced metastatic stage of PCa, which carries a poor prognosis.

METHODS

In this systematic review, we searched the PubMed, Scopus, and Web of Science online databases based on the PRISMA guideline and used all the medical subject headings (MeSH) in terms of the following search line: ("Brain Neoplasms" OR "Central Nervous System Neoplasms") and ("Prostatic Neoplasms" OR "Prostate"). Related studies were identified and reviewed.

RESULTS

A total of 59 eligible studies (902 patients) were included in this systematic review. In order to gain a deeper understanding, we extracted and presented the data from included articles based on clinical manifestations, diagnostic methods, therapeutic approaches, and prognostic status of PCa patients having BMs.

CONCLUSION

We have demonstrated the current knowledge regarding the mechanism, clinical manifestations, diagnostic methods, therapeutic approaches, and prognosis of BMs in PCa. These data shed more light on the way to help clinicians and physicians to understand, diagnose, and manage BMs in PCa patients better.

Prostate Cancer Brain Metastasis: Review of a Rare Complication with Limited Treatment Options and Poor Prognosis

Brain metastases (BM) are perceived as a rare complication of prostate cancer associated with poor outcome. Due to limited published data, we conducted a literature review regarding incidence, clinical characteristics, treatment options, and outcomes of patients with prostate cancer BM. A literature analysis of the PubMed, MEDLINE, and EMBASE databases was performed for full-text published articles on patients diagnosed with BM from prostate cancer. Eligible studies included four or more patients. Twenty-seven publications were selected and analyzed. The sources of published patient cohorts were retrospective chart reviews, administrative healthcare databases, autopsy records, and case series. BM are rare, with an incidence of 1.14% across publications that mainly focus on intraparenchymal metastases. Synchronous visceral metastasis and rare histological prostate cancer subtypes are associated with an increased rate of BM. Many patients do not receive brain metastasis-directed local therapy and the median survival after BM diagnosis is poor, notably in patients with multiple BM, dural-based metastases, or leptomeningeal dissemination. Overall, prostate cancer BM are rare and associated with poor prognosis. Future research is needed to study the impact of novel prostate cancer therapeutics on BM incidence, to identify patients at risk of BM, and to characterize molecular treatment targets.

Incidence of dural metastases in castrate-resistant prostate cancer

Purpose:

The natural history and clinical manifestations of dural metastases (DM) in castrate-resistant prostate cancer (CRPC) will change with advances in new hormonal therapy. Here, we characterised the incidence, clinical presentation, and outcomes of patients with DM in a contemporary patient cohort with CRPC.

Methods:

We retrospectively reviewed our CRPC database from 2012 to 2020. The primary outcome was the diagnosis of DM, defined as metastasis to the dura mater in the brain or spine. We describe the presenting symptoms, biochemistry, radiologic findings, and therapy sequence for all DM patients. Multivariable logistic regression was performed to identify predictors of DM.

Results:

Six of the 275 patients (2.2%) with CRPC developed DM. The average age of CRPC diagnosis for patients with DM was 65.6 years. Mean patient survival was 4.5 months after the diagnosis of DM. At the time of CRPC diagnosis, patients who developed DM were significantly younger, had lower baseline haemoglobin, higher lactate dehydrogenase (LDH), and elevated alkaline phosphatase (ALP) compared to those without DM. On multivariable analysis, younger age of CRPC diagnosis was found to be a predictor for DM.

Conclusion:

The presence of neurological symptoms in the context of younger age, anaemia, and elevated baseline LDH and ALP are associated with DM in CRPC.

Level of Evidence:

4