Brain metastases from prostate cancer: an 11-year analysis in the MRI era with emphasis on imaging characteristics, incidence, and prognosis

Malignant invasion of the central nervous system: the hidden face of a poorly understood outcome of prostate cancer

Malignancies of the central nervous system include primary brain tumors and brain metastases, the latter being the major cause of intracranial neoplasms in adults. Although prostate cancer (PCa) brain metastases are not the most common source, recent data show that the relevance of prostate cancer brain metastases (PCBM) cannot be neglected. In this review, we focus on the molecular repertory as well as on the phenotypical similarities between PCBM and primary PCa, such as the cellular evolution and the maintenance of androgen-receptor expression. Moreover, the simultaneous occurrence of PCBM with other PCa metastatic sites and the significance of the clinical heterogeneity of the disease are also discussed. In addition, a potential relationship between the heterogeneous behavior exhibited by PCBM and the co-occurrence of malignant cell clusters with distinct genetic profiles is also hypothesized, as well as the prominent role of astrocytes in the establishment of PCBM.

Brain metastases from prostate cancer: A single-center experience

OBJECTIVE

Metastases from prostate cancer to the brain are very unusual and very few case series have been reported in the literature. Present study was performed to assess the proportion of brain metastasis from prostate cancer among other brain metastasis in men, to evaluate the distribution, pattern and magnetic resonance imaging (MRI) appearance of these metastatic lesions, and prognosis of brain metastasis in patients with prostate cancer.

MATERIAL AND METHODS

Between January 2010 and November 2016, 339 males who had received radiotherapy at our department were retrospectively reviewed. After the first evaluation of patients data, we reviewed only the patients with brain metastases from prostate cancer. We evaluated MRI characteristics of metastatic brain lesions and characteristics of the patients, tumor and treatment modalities.

RESULTS

Ten of 339 patients (2.9%) had brain metastases from prostate cancer. Sixty percent of the patients had pure intraparenchymal metastasis, 20% of the patients had pure extensive dural metastasis and 20% of them had both. Seventy-five percent of the patients with intraparenchymal metastasis had multiple metastatic lesions. The median prostate specific antigen (PSA) level was 49.40 ng/mL and the Gleason score was ≥7 in all patients. Sixty percent of the patients had distant metastasis at the time of the diagnosis of prostate cancer. Median survival time in patients with brain metastasis was 4.5 months.

CONCLUSION

Lesions of brain metastasis from prostate cancer had a large variety of imaging presentation and it is very difficult to distinguish them from the other brain metastasis originating from other types of cancer. Presence of a disseminated disease, high PSA level and high Gleason score can be useful parameters for the prediction of brain metastasis from prostate cancer.

Keratin 13 expression reprograms bone and brain metastases of human prostate cancer cells

Lethal progression of prostate cancer metastasis can be improved by developing animal models that recapitulate the clinical conditions. We report here that cytokeratin 13 (KRT13), an intermediate filament protein, plays a directive role in prostate cancer bone, brain, and soft tissue metastases. KRT13 expression was elevated in bone, brain, and soft tissue metastatic prostate cancer cell lines and in primary and metastatic clinical prostate, lung, and breast cancer specimens. When KRT13 expression was determined at a single cell level in primary tumor tissues of 44 prostate cancer cases, KRT13 level predicted bone metastasis and the overall survival of prostate cancer patients. Genetically enforced KRT13 expression in human prostate cancer cell lines drove metastases toward mouse bone, brain and soft tissues through a RANKL-independent mechanism, as KRT13 altered the expression of genes associated with EMT, stemness, neuroendocrine/neuromimicry, osteomimicry, development, and extracellular matrices, but not receptor activator NF-κB ligand (RANKL) signaling networks in prostate cancer cells. Our results suggest new inhibitors targeting RANKL-independent pathways should be developed for the treatment of prostate cancer bone and soft tissue metastases.

Insidious enemy: downside to prolonged survival in prostate cancer

An 83-year-old man, a prostate cancer survivor of 10 years with multiple vertebral metastases presented with sudden onset of double vision. On examination he was found to have an isolated partial left abducens palsy with no other neurological deficits. Despite having microvascular risk factors, given his history of prostate cancer, aMRI brain scan was requested to look for a neurological cause. The scan revealed a metastatic lesion in the clivus encasing the cavernous sinus and carotid artery. He was referred to his oncologist for further management, however he opted out of further treatment and succumbed to his illness a month later. This case report includes a literature review of cases with clivus metastases secondary to prostate cancer. It highlights the importance of carefully examining eye movements and having a high index of suspicion for the subtlest sign that may suggest brain metastases in elderly patients with prostate cancer with prolonged survival.

Headache Caused by Brain Metastases of Castration-resistant Prostate Cancer during Cabazitaxel Therapy

We describe the case of a 55-year-old man who underwent four cycles of cabazitaxel therapy for castration-resistant prostate cancer (CRPC). After the fourth cycle of cabazitaxel, the patient experienced severe headaches. Brain gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) revealed multiple brain metastases. A few days later, the patient suffered impaired consciousness that progressed rapidly. The patient was treated for the symptoms of increased intracranial pressure and underwent whole-brain radiation. One month later, the patient's consciousness level and headache had improved. Although brain metastases of prostate cancer are rare, the possibility of brain metastases should be considered for prostate cancer patients, especially when a CRPC patient complains of headache. Additionally, even if major conditions such as cerebral hemorrhage are excluded by the use of non-contrast-enhanced computed tomography, brain Gd contrast-enhanced MRI should be performed in consideration of the possibility of brain metastases of prostate cancer.

Cerebellar Metastases From Prostate Cancer on 68Ga-PSMA PET/CT

Ga prostate-specific membrane antigen PET/CT is increasingly used to evaluate extent of disease in prostate carcinoma. Parenchymal brain metastases originating from prostate cancer have highly variable imaging appearance. We present a 77-year-old man with cerebellar metastasis from prostate cancer showing focal uptake on prostate-specific membrane antigen PET/CT.

Rare Sites of Metastases in Prostate Cancer Detected on Ga-68 PSMA PET/CT Scan-A Case Series

Ga-68 labeled prostate-specific membrane antigen (PSMA) whole body PET/CT scan is a novel upcoming modality for the evaluation of prostate cancer. We present three cases of prostate cancer showing rare sites of metastases like brain, penis, and liver detected on Ga-68 PSMA PET/CT scan thus emphasizing its role in lesion detection and staging.

Detection of brain metastasis with 68Ga-labeled PSMA ligand PET/CT: a novel radiotracer for imaging of prostate carcinoma

Brain metastasis in prostate cancer is rare and not expected at initial presentation especially when the patient is asymptomatic for the same. A 45-year-old male patient undergoing initial evaluation for newly diagnosed prostatic adenocarcinoma was referred to our department for 99mTc-MDP bone scintigraphy. As part of the study protocol, he also underwent Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68(HBED-CC)] (68Ga-PSMA) PET/CT, which revealed tracer accumulation in brain lesions, apart from localization in the primary, lymph node, and bone metastases. A subsequent MR evaluation confirmed brain metastases.

Brain metastasis and treatment

Despite major therapeutic advances in the management of patients with systemic malignancies, management of brain metastases remains a significant challenge. These patients often require multidisciplinary care that includes surgical resection, radiation therapy, chemotherapy, and targeted therapies. Complex decisions about the sequencing of therapies to control extracranial and intracranial disease require input from neurosurgeons, radiation oncologists, and medical/neuro-oncologists. With advances in understanding of the biology of brain metastases, molecularly defined disease subsets and the advent of targeted therapy as well as immunotherapeutic agents offer promise. Future care of these patients will entail tailoring treatment based on host (performance status and age) and tumor (molecular cytogenetic characteristics, number of metastases, and extracranial disease status) factors. Considerable work involving preclinical models and better clinical trial designs that focus not only on effective control of tumor but also on quality of life and neurocognition needs to be done to improve the outcome of these patients.

Characterization of the stem cell niche and its importance in radiobiological response

Normal tissues are organized hierarchically with a small number of stem cells, able to self-renew and give rise to all the differentiated cells found in the respective specialized tissues. The undifferentiated, multipotent state of normal stem cells is codetermined by the constituents of a specific anatomical space that hosts the normal stem cell population, called the "stem cell niche." Radiation interferes not only with the stem cell population but also with the stem cell niche, thus modulating a complex regulatory network. There is now mounting experimental evidence that many solid cancers share this hierarchical organization with their tissue of origin, with the cancer stem cells also occupying specialized niches. In this review, we highlight some of the best-characterized aspects of normal tissue stem cells, cancer stem cells, and their niches in the bone marrow, gut, and brain, as well as their responses to ionizing radiation.