Factors associated with overall survival in breast cancer patients with leptomeningeal disease (LMD): a single institutional retrospective review

BACKGROUND

Breast cancer-related leptomeningeal disease (BC-LMD) is a dire diagnosis for 5-8% of patients with breast cancer (BC). We conducted a retrospective review of BC-LMD patients diagnosed at Moffitt Cancer Center from 2011 to 2020, to determine the changing incidence of BC-LMD, factors which are associated with the progression of BC CNS metastasis to BC-LMD, and factors which are associated with OS for patients with BC-LMD.

METHODS

Patients with BC and brain/spinal metastatic disease were identified. For those who eventually developed BC-LMD, we used Kaplan-Meier survival curve, log-rank test, univariable, and multivariate Cox proportional hazards regression model to identify factors affecting time from CNS metastasis to BC-LMD and OS.

RESULTS

128 cases of BC-LMD were identified. The proportion of BC-LMD to total BC patients was higher between 2016 and 2020 when compared to 2011-2015. Patients with HR+ or HER2 + BC experienced longer times between CNS metastasis and LMD than patients with triple-negative breast cancer (TNBC). Systemic therapy and whole-brain radiation therapy (WBRT) was associated with prolonged progression to LMD in all patients. Hormone therapy in patients with HR + BC were associated with a delayed BC-CNS metastasis to LMD progression. Lapatinib treatment was associated with a delayed progression to LMD in patients with HER2 + BC. Patients with TNBC-LMD had shorter OS compared to those with HR + and HER2 + BC-LMD. Systemic therapy, intrathecal (IT) therapy, and WBRT was associated with prolonged survival for all patients. Lapatinib and trastuzumab therapy was associated with improved OS in patients with HER2 + BC-LMD.

CONCLUSIONS

Increasing rates of BC-LMD provide treatment challenges and opportunities for clinical trials. Prospective trials testing lapatinib and/or similar tyrosine kinase inhibitors, IT therapies, and combination treatments are urgently needed.

Spatial transcriptomics analysis identifies a unique tumor-promoting function of the meningeal stroma in melanoma leptomeningeal disease

Leptomeningeal disease (LMD) remains a rapidly lethal complication for late-stage melanoma patients. The inaccessible nature of the disease site and lack of understanding of the biology of this unique metastatic site are major barriers to developing efficacious therapies for patients with melanoma LMD. Here, we characterize the tumor microenvironment of the leptomeningeal tissues and patient-matched extra-cranial metastatic sites using spatial transcriptomic analyses with in vitro and in vivo validation. We show the spatial landscape of melanoma LMD to be characterized by a lack of immune infiltration and instead exhibit a higher level of stromal involvement. We show that the tumor-stroma interactions at the leptomeninges activate pathways implicated in tumor-promoting signaling, mediated through upregulation of SERPINA3 at the tumor-stroma interface. Our functional experiments establish that the meningeal stroma is required for melanoma cells to survive in the CSF environment and that these interactions lead to a lack of MAPK inhibitor sensitivity in the tumor. We show that knocking down SERPINA3 or inhibiting the downstream IGR1R/PI3K/AKT axis results in re-sensitization of the tumor to MAPK-targeting therapy and tumor cell death in the leptomeningeal environment. Our data provides a spatial atlas of melanoma LMD, identifies the tumor-promoting role of meningeal stroma, and demonstrates a mechanism for overcoming microenvironment-mediated drug resistance unique to this metastatic site.

Epstein‑Barr virus‑associated primary central nervous system lymphoma in an immunosuppressed patient with a comorbid autoimmune disorder: A case report

Patients with primary central nervous system lymphoma (PCNSL) typically present with non-focal neurological symptoms, including disorientation, poor balance and memory loss with unifocal or multifocal periventricular lesions seen on MRI. Deviations from these characteristic findings can delay diagnosis and lead to additional diagnostic tests being needed. The present study reports a 68-year-old man with a recent varicella zoster infection and history of acetylcholine receptor antibody-positive myasthenia gravis who received mycophenolate mofetil for 22 years. He presented with left eye vision changes and cognitive memory deficits. A brain MRI showed an enhancing lesion within his left medulla extending to the cerebellum. Cerebrospinal fluid analysis was positive for Epstein-Barr virus (EBV) and negative for malignancy. He was diagnosed with varicella zoster virus vasculopathy. At 3 months later, a repeat brain MRI showed multiple new enhancing lesions developing bilaterally along the periventricular white matter. Soon after, he presented to a local ER with acute left-sided blurry vision and worsening memory loss, and he began receiving steroids. Because of rapid symptom progression, he underwent resection of the left frontal lesion, which showed EBV-induced diffuse large B-cell lymphoma (DLBCL). Mycophenolate mofetil was discontinued, and within 24 h of one dose of intravenous 500 mg/m2 rituximab, he had a dramatic improvement in left eye vision and memory loss. He experienced mixed responses to rituximab after 3 cycles. Following one dose of high-dose methotrexate, he developed subsequent chronic kidney disease and required dialysis. He received whole-brain radiation therapy with craniospinal radiation and is currently in complete remission. An EBV-induced DLBCL diagnosis should be highly considered for patients with periventricular lesions and EBV-positive cerebrospinal fluid. Misdiagnosis or delay in PCNSL diagnosis because of atypical features in disease presentation and radiographic findings could lead to PCNSL progression and worsening neurological deficits.

Factors improving overall survival in breast cancer patients with leptomeningeal disease (LMD): A single institutional retrospective review

Background

Breast cancer-related leptomeningeal disease (BC-LMD) is a dire diagnosis for 5-8% of patients with breast cancer (BC). We conducted a retrospective review of BC-LMD patients diagnosed at Moffitt Cancer Center (MCC) from 2011-2020, to determine the changing incidence of BC-LMD, which factors impact progression of BC CNS metastasis to BC-LMD, and which factors affect OS for patients with BC-LMD.

Methods

Patients with BC and brain/spinal metastatic disease were identified. For those who eventually developed BC-LMD, we used Kaplan-Meier survival curve, log-rank test, univariable, and multivariate Cox proportional hazards regression model to identify factors affecting time from CNS metastasis to BC-LMD and OS.

Results

128 cases of BC-LMD were identified. The proportion of BC-LMD to total BC patients was higher between 2016-2020 when compared to 2011-2015. Patients with HR + or HER2 + BC experienced longer times between CNS metastasis and LMD than patients with triple-negative breast cancer (TNBC). Systemic therapy and whole-brain radiation therapy (WBRT) prolonged progression to LMD in all patients. Hormone therapy in patients with HR + BC delayed BC-CNS metastasis to LMD progression. Lapatinib delayed progression to LMD in patients with HER2 + BC. Patients with TNBC-LMD had shorter OS compared to those with HR + and HER2 + BC-LMD. Systemic therapy, intrathecal (IT) therapy, and WBRT prolonged survival for all patients. Lapatinib and trastuzumab improved OS in patients with HER2 + BC-LMD.

Conclusions

Increasing rates of BC-LMD provide treatment challenges and opportunities for clinical trials. Trials testing lapatinib and/or similar tyrosine kinase inhibitors, IT therapies, and combination treatments are urgently needed.

NCMP-17. PLASMA EXCHANGE FOR IMMUNE CHECKPOINT INHIBITOR INDUCED ACUTE DEMYELINATING POLYNEUROPATHY REFRACTORY TO IVIG

The use of immune checkpoint inhibitors in the treatment of cancer has gained prominence due to their effectiveness. Unfortunately, neurological immune-related adverse events represent a growing problem in neuro-oncology practice. Many of these cases are rare and their diagnoses and management can be challenging. We present a case of a 69-year-old male with urothelial carcinoma status post left nephrectomy who developed bilateral lower extremity weakness that began following his first dose of Atezolizumab. After three doses, his lower extremity weakness worsened to the point where he could not walk. A NCV study was performed and was consistent with acute demyelinating polyneuropathy. A cervical MRI (Magnetic Resonance Imaging) showed an enhancing lesion at C6-C8. He was treated with three days of intravenous methylprednisolone every six hours for three days followed by three days of 0.4gm/kg IVIG. He regained his ability to walk after IVIG treatment. The enhancing lesion noted on MRI remained. Three weeks after the first IVIG treatment, he declined significantly, redeveloping symptoms where he could not ambulate and required assistance to use the toilet. He had no lower extremity reflexes and had loss of proprioception of his hands. He was scheduled for another IVIG infusion at .4gm/kg followed by a dose of IVIG .6gm/kg the next day, and then four more days of IVIG .25gm/kg. His lower extremity weakness and difficulty walking remained so he was arranged for plasmapheresis x five cycles. His weakness improved, reflexes returned, and he no longer had proprioceptive loss of his hands. A cervical MRI obtained one month after plasma exchange showed resolution of the C6-C8 enhancing lesion. He is now ambulating with a cane. This case highlights the effectiveness of plasma exchange in a case that was refractory to IVIG

CTIM-01. TITLE: PHASE 1B STUDY OF AVELUMAB AND WHOLE BRAIN RADIOTHERAPY (WBRT) IN PATIENTS WITH LEPTOMENINGEAL DISEASE (LMD): PRELIMINARY RESULTS

BACKGROUND

LMD from systemic cancer has a dismal prognosis with median survivals of 8-10 weeks. A phase 2 trial of PD-1 inhibitor monotherapy in LMD showed median overall survival (OS) of 3.6 months (Brastianos P et al., 2020). We determined the safety/efficacy of avelumab, a PD-L1 inhibitor with WBRT in patients with LMD (NCT0371768). This combination can treat the tumor directly and increase BBB permeability (Li, 2003; Nordal, 2005) allowing the increased egress of activated T cells into the meninges/CSF.

METHODS

Patients received concurrent avelumab 800 mg IV q2 weeks for ≤ 5 cycles (unless PD or unacceptable toxicity) with WBRT 3000 cGy in 10 fractions. Primary endpoints are safety/DLTs and OS at 3 months. Secondary endpoints are CSF T-cell/cytokine profiles (scRNAseq, phosophoproteomics etc.).

RESULTS

A total of 15 patients (7 breast, 7 lung & 1 other) were enrolled (n = 13 F, ages 32-79). Pts receiving anti-PD-1/PD-1L/PD-L2/CD137,CTLA-4 therapy ≤ 6 months prior were excluded. Three of 15 patients had grade 3/4 AEs (diarrhea, lymphopenia, decreased WBC count in 3 patients). Seven patients (50%) were alive at 3 or 6 months. The estimated median follow up in 14 patients is 4.75 months (range, 0.92 – 30.05 months, 95% CI is 1.32 ~ 19.82). The median PFS is 3.75 months (95% CI = 0.85-15.16) and median OS is 6.89 months (95% CI = 1.18-14.7).

CONCLUSIONS

The combination of avelumab and WBRT is safe, well tolerated, and demonstrates encouraging activity in patients with LMD with an OS that is longer than other published series. Multiple platform interrogation of CSF (analysis underway) will determine mechanisms of LMD therapeutic/resistance effects.

NCMP-04. COMBINATION BRAF/MEK INHIBITION IMPROVES SURVIVAL WITH LEPTOMENINGEAL DISEASE FROM MELANOMA IN A SINGLE INSTITUTIONAL REVIEW AT MOFFITT CANCER CENTER

Melanoma is third most common cancer to metastasize to the leptomeningeal space and confers a dismal prognosis. We retrospectively identified 87 cases of melanoma related leptomeningeal disease (M-LMD) diagnosed between 2011-2020 at Moffitt Cancer Center. The average age at diagnosis was 54 years (range 28-93 years) with a male predominance (50 men vs 36 women). There was a significant increase in median overall survival (OS) for patients with BRAF V600E mutation, but only if they were treated with combined BRAF/MEK inhibitors after diagnosis of LMD (5.54 months vs 1.39 months; p < 0.01). Immune checkpoint inhibitors also associated with a small but significant increase in OS when given after diagnosis of M-LMD (2.73 months vs 1.38mths; p < 0.01). There was no association between OS and gender (p > 0.05). The current data supports use of BRAF/MEK inhibitors for treatment of BRAF V600E mutated M-LMD. More work is needed to improve OS for these patients and patients without a targetable mutation and M-LMD.

INNV-23. MANAGING CENTRAL NERVOUS SYSTEM MANIFESTATIONS OF CHRONIC GRAFT VERSUS HOST DISEASE FOLLOWING HEMATOPOIETIC STEM CELL TRANSPLANTATION: A CASE REPORT

Central nervous system (CNS) manifestation of chronic graft versus host disease (cGVHD) is a rare, difficult to diagnose phenomenon that can follow allogeneic hematopoietic stem cell transplantation (HSCT). CNS-cGVHD typically onsets 2-31 months post-transplant, involves diffuse infiltration of inflammatory cells, demyelination, and cerebral vasculitis, and is associated with an extremely poor prognosis. We present a case of a 37-year-old man who developed seizures, myopathy, bilateral upper and lower extremity weakness, confusion, and irritability almost 2 years after HSCT for acute myeloid leukemia (AML). CNS-cGVHD diagnosis was confidently determined via magnetic resonance imaging (MRI) demonstrating enhanced focal white matter lesions, cerebrospinal fluid (CSF) studies demonstrating elevated globulin (12.7 mg/dL; normal range: 0-6 mg/dL) and elevated immunoglobulin G (IgG) synthesis rate (13.9 mg/d; normal range: ≤ 8 mg/d), and a right brain biopsy demonstrating encephalitis, perivascular inflammation, microglial activation, and gliosis with predominately intramural and perivascular CD3+ T-cells, CD4+ and CD8+ cells. Complete resolution of neurological symptoms, including seizures, was achieved with a combination of steroids, ibrutinib, intravenous immunoglobulin (IVIG), and anti-seizure medications. Improvements to CNS-cGVHD was further indicated by normalized MRI studies without abnormal enhancements and improved CSF studies with reduction in globulin levels (11.3 mg/dL) and complete normalization of IgG synthesis rate (≤ 0 mg/d). It is imperative that CNS-cGVHD be considered in patients that present with neurological signs post-transplant. An early, confident diagnosis generates prompt intervention and as demonstrated, can lead to complete resolution of neurological symptoms.

NCMP-23. A UNIQUE CASE OF CHOREIFORM DYSKINESIAS IN A PATIENT WITH METASTATIC RENAL CELL CARCINOMA

BACKGROUND

Dyskinesias in cancer patients present a diagnostic challenge to clinicians. Etiologies can include paraneoplastic syndromes, chemotherapy related side effects, or primary movement disorders. This is a unique case of choreoathetotic dyskinesias in a patient with metastatic renal cell carcinoma while undergoing treatment with cabozantinib in combination with either placebo or the investigational drug CB-839 (telanglenastat) while on the clinical trial MCC 19671.

RESULTS

We present a 69 year old gentleman with a history of metastatic renal cell carcinoma who developed choreoathetotic dyskinesias eleven months after enrolling in a phase 2 blind study MCC 19671. His CSF paraneoplastic panel and MRI brain imaging were unremarkable. His symptoms abated with stopping his clinical trial drug, after which he withdrew from the trial and opted to continue cabozantinib alone. Unfortunately he developed worsening dyskinesias a week after restarting cabozantinib which was then stopped permanently. He was treated with prednisone and plasma exchange with improvement in his symptoms. Unfortunately, he passed away due to progression of disease two months later.

CONCLUSIONS

This case highlights the first case of choreiform dyskinesias most likely associated with CB-839/cabozantinib, since the patient’s symptoms significantly improved upon stopping the medications. The patient could also have had a novel paraneoplastic-associated antibody which has not been discovered yet. As the investigation into novel chemotherapeutic agents for malignancies continues, the incidence of drug related dyskinesias will need to be monitored.

CNSC-03. NEURONAL INTERMEDIATE FILAMENT (NIF) ANTIBODY POSITIVE PARANEOPLASTIC SYNDROME IN A PATIENT WITH METASTATIC NEUROENDOCRINE PANCREATIC CARCINOMA AND TREATMENT WITH IPILIMUMAB/NIVOLUMAB

Immune checkpoint inhibitors, such as ipilimumab (CTL-4) and nivolumab (PD-1) have shown effectiveness in many types of neoplasia. This combination has been used as salvage immunotherapy for high grade metastatic pancreatic carcinoma. Nevertheless, severe neurologic immune-mediated adverse effects can result from the use of this treatment. We present a case of a 64-year-old woman with metastatic neuroendocrine pancreatic carcinoma with abrupt left facial and oculomotor cranial nerve palsy as well spastic tetraplegia after one dose of ipilimumab/nivolumab. She had a history of sudden onset diplopia, fever and ground-level fall a few hours after her initial dose of immunotherapy. Initial laboratory assessment showed pronounced lymphocyte predominant leukocytosis and mild chronic hyponatremia. In the following hours, she developed right mydriasis, right sided fast phase nystagmus and right central facial paralysis along with weakness and spasticity in four extremities. Neuroimaging of brain, orbits and CTL spine showed enhancement of intra-orbital and intracranial optic nerves as well chiasm, linear enhancement from C4-C7 and cauda equina, as well as abnormal signal along thoracic spinal cord and conus medullaris. Routine EEG demonstrated non-etiology specific encephalopathy. Lumbar puncture had normal opening pressure, mild pleocytosis, hyper-proteinorrhachia and normal glucose. Viral panel and cytology in the CSF were negative, and myeline basic protein was elevated. She was treated with high dose steroids which improved overall strength and CN palsies. Twenty days after initial presentation, she suddenly developed hypotension, tachypnea, and altered cognition. The patient and family opted for comfort measures only. She passed away that same day. Late report of CSF antibody panels showed positive cell-based assay for heavy and light chain NIF with a titer of 1:512. This case emphasizes the importance of recognition of anti-body mediated paraneoplastic syndromes in patients treated with immunotherapy, their appropriate treatment and prognosis.

Patient satisfaction and cost savings analysis of the telemedicine program within a neuro-oncology department

Purpose

Unique challenges exist in the utilization of telemedicine for neurological and surgical specialties. We examined the differences in patient satisfaction for telemedicine versus in-person visits within a Neuro-Oncology Program to assess whether there was a difference between surgical and medical specialties. We also examined the potential cost savings benefits of utilizing telemedicine.

Methods

1189 Press Ganey surveys in the Department of Neuro-Oncology (982 in-person and 207 telemedicine) by surgical and medical neuro-oncology patients between 04/01/2020 and 06/30/2021 were reviewed. Survey results were divided into 4 categories (Access, Provider, Technology (telemedicine only), and Overall Satisfaction). Results were analyzed for the impact of telemedicine versus in-person visits, and gender, age, insurance, and specialty. Cost savings were calculated based on potential travel distance and lost productivity.

Results

Survey results from telemedicine visits demonstrated that patients with private insurance returned higher scores in the Provider (p = 0.0089), Technology (p = 0.00187), and Overall (p = 0.00382) categories. Surgical patients returned higher scores for Access (p = 0.0015), Technology (p = 0.0002), and Overall (p = 0.0019). When comparing telemedicine to in-person scores, in-person scored higher in Provider (p = 0.0092) for all patients, while in-person scored higher in Access (p = 0.0252) amongst surgical patients. Cost analysis revealed that telemedicine allowed patients to save an average of 4.1 to 5.6 h per visit time and a potential cost savings of up to $223.3 ± 171.4.

Conclusion

Telemedicine yields equivalent patient satisfaction when employed in surgical as compared to medical Neuro-Oncology patients with the potential to lessen the financial and time burden on neuro-oncology patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-022-04173-7

A preclinical model of patient-derived cerebrospinal fluid circulating tumor cells for experimental therapeutics in leptomeningeal disease from melanoma

BACKGROUND

Leptomeningeal disease (LMD) occurs as a late complication of several human cancers and has no rationally designed treatment options. A major barrier to developing effective therapies for LMD is the lack of cell-based or preclinical models that recapitulate human disease. Here, we describe the development of in vitro and in vivo cultures of patient-derived cerebrospinal fluid circulating tumor cells (PD-CSF-CTCs) from patients with melanoma as a preclinical model to identify exploitable vulnerabilities in melanoma LMD.

METHODS

CSF-CTCs were collected from melanoma patients with melanoma-derived LMD and cultured ex vivo using human meningeal cell-conditioned media. Using immunoassays and RNA-sequencing analyses of PD-CSF-CTCs, molecular signaling pathways were examined and new therapeutic targets were tested for efficacy in PD-CSF-CTCs preclinical models.

RESULTS

PD-CSF-CTCs were successfully established both in vitro and in vivo. Global RNA analyses of PD-CSF-CTCs revealed several therapeutically tractable targets. These studies complimented our prior proteomic studies highlighting IGF1 signaling as a potential target in LMD. As a proof of concept, combining treatment of ceritinib and trametinib in vitro and in vivo demonstrated synergistic antitumor activity in PD-CSF-CTCs and BRAF inhibitor-resistant melanoma cells.

CONCLUSIONS

This study demonstrates that CSF-CTCs can be grown in vitro and in vivo from some melanoma patients with LMD and used as preclinical models. These models retained melanoma expression patterns and had signaling pathways that are therapeutically targetable. These novel models/reagents may be useful in developing rationally designed treatments for LMD.

NCMP-21. IMMUNE-RELATED ACUTE MOTOR AXONAL NEUROPATHY: A SMALL CASE SERIES AND REVIEW OF THE LITERATURE

BACKGROUND

Immunotherapy revolutionized cancer treatment in the past decade, with a significant increased survival in patients with solid tumors. However, immune checkpoint inhibitors (ICIs) have been associated with a growing number of neurotoxicities, some of which can be fatal if not recognized and treated promptly. Some of these neurotoxicities include very uncommon syndromes like Acute Motor Axonal Neuropathy (AMAN). Herein we present four oncological cases of patients who underwent immunotherapy and developed AMAN.

METHODS

Four patients were diagnosed with immune-related AMAN between 2017 and 2000 at H. Lee Moffitt Cancer Center. Patients were treated with standard of care.

RESULTS

We describe four oncological patients who developed a motor axonal neuropathy (i.e., AMAN) confirmed on nerve conduction studies following 2 cycles of immunotherapy, including a 28 year old woman with melanoma brain metastasis and a 50 year old woman with renal cell carcinoma both treated with ipilimumab and nivolumab, a 32 year old man with Hodgkin lymphoma who was treated with nivolumab and brentuximab, and a 77 year old woman with renal urothelial cancer who was treated with pembrolizumab and cabozantinib. All four patients were promptly recognized as having immune-related neurotoxicity (irNs), were promptly treated (i.e., high dose steroids +/- IVIG +/- other immunomodulators), and significantly improved and have remained stable.

CONCLUSION

This is the first case series of patients with AMAN following two cycles of immunotherapy, who were successfully treated. It is crucial to develop a better understanding of irNs, including those rare conditions that are difficult to diagnose and treat, as the utilization of these immunomodulating therapies continues to expand to include other solid malignancies. Neurologists should be involved early on in any case of suspected irN to assist in the management of these complicated patients and a swift work up should be initiated for timely diagnosis and treatment.

P08.01 Immune-Related Acute Motor Axonal Neuropathy: A Small Case Series and Review of the Literature

BACKGROUND

Immunotherapy have revolutionized cancer treatment in the past decade, with a significant increased survival in patients with solid tumors. However, the use of immune checkpoint inhibitors (ICIs) has been associated with a growing number of neurotoxicities, some of which can be fatal if not recognized and treated promptly. Some of these neurotoxicities include very uncommon syndromes like Acute Motor Axonal Neuropathy (AMAN). Herein we present four oncological cases of patients who underwent immunotherapy and developed AMAN.

METHODS

Four patients were diagnosed with immune-related AMAN between 2017 and 2000 at H. Lee Moffitt Cancer Center. The patients were treated with standard of care and currently follow up in clinic.

RESULTS

We describe four oncological patients who developed a motor axonal neuropathy (i.e., AMAN) confirmed on nerve conduction studies following 2 cycles of immunotherapy, including a 28 year old woman with melanoma brain metastasis and a 50 year old woman with renal cell carcinoma both treated with ipilimumab and nivolumab, a 32 year old man with Hodgkin lymphoma who was treated with nivolumab and brentuximab, and a 77 year old woman with renal urothelial cancer who was treated with pembrolizumab and cabozantinib. All four patients were promptly recognized as having immune-related neurotoxicity (irNs), were promptly treated (i.e., high dose steroids +/- IVIG +/- other immunomodulators), and significantly improved and have remained stable.

CONCLUSION

This is the first case series of patients with AMAN following two cycles of immunotherapy, who were successfully treated. It is crucial to develop a better understanding of the irNs associated with ICIs, including those rare conditions that are difficult to diagnose and treat, as the utilization of these immunomodulating therapies continues to increase and expand to include other solid malignancies. Neurologists should be involved early on in any case of suspected irN to assist in the management of these complicated patients and a swift work up should be initiated for timely diagnosis and treatment.

LMD-07. In Vitro AND In Vivo Culture of Patient Derived-Cerebral Spinal Fluid-Circulating Tumor Cells (PD-CSF-CTCs) in Leptomeningeal Disease (LMD) From Melanoma to Identify Novel Treatment Strategies

Background

Approximately 5% of melanoma patients (pts) will develop LMD. Currently there is no effective treatments for this disease. A significant barrier to the development of effective therapies has been the inability to culture CSF-CTCs for functional analysis. For the first time, we were able to successfully expand CSF-CTCs in vitro and in vivo. We assessed gene signatures of PD-CSF-CTCs to determine novel targets for therapy. As a proof of concept, we tested the efficacy of combining ceritinib (cer), an IGF-1R inhibitor and trametinib (tra), a MEK inhibitor, against LMD.

Methods

CSF from 11 pts were collected from various sources (ie: LPs, Ommayas, rapid autopsies). PD-CSF-CTCs were expanded in vitro in conditioned media and in vivo using cell line-derived xenograft model. Single-cell RNA-sequencing (scRNAseq) analysis was performed to assess transcriptional profiles of PD-CSF-CTCs.

Results

Of the total 61 PD-CSF-CTCs collected from 11 pts (avg: 4.07 CSF collections/patient), we successfully cultured PD-CSF-CTCs from 3 pts (20%) and were able to grow them in vivo from 2 pts (18%). scRNAseq identified IGF-1R, Sox9, ErbB3 and MLANA were among the enriched genes for PD-CSF-CTCs. IGF-1R inhibition by cer and depletion by CRISPR suppressed cell growth. We evaluated the responses of cer + tra treatment in vitro and found that combining these agents produced drug synergy against PD-CSF-CTCs and resensitized BRAF inhibitor-resistant melanoma cell line, WM164R. In vivo LMD xenograft model showed cer + tra treatment significantly prolonged median survival of PD-CSF-CTCs LMD (control: 27 days vs treatment: 38.5 days; P value < 0.032) and WM164R LMD (control: 35 days vs treatment: MS not reached; P value < 0.047).

Conclusions

Though the sample size is small, this is the first report of the successful in vitro and in vivo culture of CSF-CTCs from pts with LMD.

LMD-05. Phase 1B Study of Avelumab and Whole Brain Radiotherapy (WBRT) in Patients with Leptomeningeal Disease (LMD): Preliminary Results

Background

LMD has a dismal prognosis with median survivals of 8–10 weeks. Recently the first phase 2 trial of PD-1 inhibitor monotherapy in solid tumor LMD showed median overall survival (OS) 3.6 months. We aimed to determine the safety/efficacy of avelumab with WBRT in patients with LMD from solid malignancies (NCT0371768). This combination can treat tumor directly and increase the permeability of the blood-brain-barrier with increased egress of activated T cells into the meninges/CSF and facilitated Avelumab entry into the CSF.

Hypothesis

Combination radioimmunotherapy will produce an activated immunocyte/cytokine profile in CSF.

Methods

Patients received concurrent Avelumab 800mg IV q2weeks x≤5 cycles with WBRT 3000cGy, 10 fractions. Primary endpoints: Safety/DLTs and OS at 3 months. Secondary endpoints: CSF T-cell/cytokine profiles (scRNAseq/phosophoproteomics) and clinical outcomes, to be performed when all 15 patients are accrued to minimize batch effects.

Results

Ten patients (5 breast, 4 lung & 1 undifferentiated sinonasal carcinoma) were enrolled (n=8 females, n=2 males, ages 32–79); n=1 patient did not complete WBRT. Patients who received anti-PD-1/PD-1L/PD-L2/CD137/CTLA-4 therapy within 6 months prior to enrollment were excluded. 30% had grade 3 AEs at least possibly related to treatment (n=3 diarrhea, lymphopenia, decreased WBC count). There were no grade 4–5 toxicities. Six patients (66.7%) were alive at 3 months. The estimated median follow up in 9 patients (regardless whether patients failed or not) is 10.49 months (range, 0.95–19.82 months, 95% CI) and the estimated median follow up survival was 19.8 months assessed using the reverse Kaplan-Meier method. Median PFS is 4.27 months (range, 0.30–16.73 months, 95% CI).

Conclusions

In this pilot study, combination of Avelumab and WBRT is safe, and demonstrates encouraging activity in patients with solid tumor LMD. Multiple platform interrogation of CSF may determine mechanisms of LMD therapeutic effects and differentiate responders from non-responders.

Rituximab for Immune Checkpoint Inhibitor Myasthenia Gravis

The use of immune checkpoint inhibitors (iCPI) in the treatment of multiple cancers has gained prominence due to their high efficacy. However, neurological immune-related adverse events (irAEs) such as myasthenia gravis (MG) have been associated with iCPI therapy. Most of these neurological irAEs are rare, and in many cases, their diagnoses and management can be challenging. 

We present a case of a 70-year-old woman with stage IIIC melanoma who developed a new onset of gradually progressive dyspnea, diplopia, and bilateral ptosis following treatment with one cycle of nivolumab and ipilimumab (Nivo+Ipi). She was diagnosed with MG via positive serum acetylcholine receptor (AChR) antibodies. She had developed a severe dyspnea at rest, which was refractory to multiple immune-suppressive therapies including prednisone, pyridostigmine, and intravenous immunoglobulin (IVIG). Subsequently, she was treated with rituximab 375 mg/m² monthly every four weeks with significant improvement of her symptoms within 48 hours each time.

As the implementation of immunotherapy increases in medical practice, irAEs may become more apparent. When first-line therapies are not adequate, other alternative therapies should be explored. This case of MG as an irAE shows that rituximab can provide a potential benefit to treating patients with immunotherapy-induced MG who are refractory to other standard treatments. Prospective studies are needed to further evaluate the efficacy of rituximab in the management of irAEs.

Developments in therapy for brain metastases in melanoma patients

Introduction: Cutaneous melanoma brain metastases (MBM) are a major cause of morbidity and mortality. While cytotoxic agents, interferon, or interleukin-2, have been used with some success in extracranial disease, limited efficacy is demonstrated in MBM. The rare patient with long-term survival presented with limited intracranial disease amenable to surgery or radiation therapy. However, the development of targeted therapy and immunotherapy over the last decade has significantly improved overall survival in this formerly devastating presentation of metastatic melanoma.Areas covered: This article reviews the mechanism of brain metastasis, challenges with treating the central nervous system, historical treatment of MBM, and outcomes in clinical trials with targeted therapy and immunotherapy.Expert opinion: The MBM patient population now, more than ever, requires a multidisciplinary approach with surgery, radiation therapy, and the use of newer systemic therapies such as immunotherapy agents and targeted therapy agents. MBM has traditionally been excluded from clinical trials for systemic therapy due to poor survival. However, recent data show overall survival rates have significantly improved, supporting the need for inclusion of MBM patients in systemic therapy clinical trials. Understanding the mechanisms of therapeutic activity in the brain, resistance  mechanisms, and the appropriate multi-modality treatment approach requires further investigation. Nevertheless, these therapies continue to give some hope to patients with historically poor survival.

Abstract 2359: Using the glycolytic inhibitor 2-fluorodeoxy-D-glucose, a novel glycolytic inhibitor approach to target the chemoresistant, hypoxic cell population in advanced LHBETATAG retinal tumors

Purpose: The aim of the current study is to assess the impact of 2-fluorodeoxy-D-glucose on tumor burden and hypoxia in the LHBETATAG retinal tumors. Methods: The study protocol was approved by the University of Miami Institutional Animal Care and Use Review Board Committee and the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. 17-week-old (n=54) LHBETATAG transgenic mice were treated with 2-fluorodeoxy-D-glucose or saline control. These animals received three different treatments. They were treated: (1) with one injection and sacrificed at one day post-treatment, (2) with one injection and sacrificed at one week post-treatment, or (3) twice a week for three weeks and sacrificed at one day post-last injection. At the time of enucleation, all eye samples were snap frozen and analyzed for tumor burden and hypoxia using immunohistochemical techniques. Average densities of the different groups were statistically analyzed using ANOVA. Results were considered significant if p≤ 0.05. Results: There was no apparent toxicity associated with 2-fluorodeoxy-D-glucose treatment. There was a significant reduction in tumor burden following treatment with 2-fluorodeoxy-D-glucose at 1 day (86%) and 3 weeks (63%) post-treatment (p≤0.05). There was no reduction of tumor burden observed when mice were treated with 1 injection and eyes harvested at 1 week post-treament (2%, p=0.0640). There was a significant reduction of hypoxia areas following treatment with 2-fluorodeoxy-D-glucose at 1 day (100%) and 3 weeks (75%) post-treatment (p≤0.05). There was an increase in hypoxia of 12% following treatment at 1 week post-injection, but this increase was not statistically significant. Conclusions: 2-FDG significantly reduces tumor burden and tumor hypoxia following a single injection, with continued efficacy following repeated injections for 3 weeks. 2-FDG treatment is efficacious in murine retinoblastoma tumors and may enhance tumor control when combined with other therapies. 2-FDG appears to target hypoxic cells, a population that has been resistant to chemotherapy and radiation. Additionally, 2-FDG is commonly used in medical imaging and does not pose significant toxicities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2359. doi:1538-7445.AM2012-2359

Abstract 4642: Combined glycolytic inhibition and anti-vascular treatment in retinoblastoma: Novel strategy for tumor control avoids chemotherapy

Purpose: The purpose of this study was to evaluate the combination treatment of glycolytic inhibitors and anti-angiogenic agents on tumor burden and hypoxia in advanced retinoblastoma using the LHbetaTag murine transgenic retinoblastoma model. Methods: Under IACUC protocol, thirty advanced LHbetaTag mice (16 weeks of age) were divided into 5 groups (n=6 per group) and treated with periocular injections of (a) saline, (b) 2-deoxy-glucose (2-DG), (c) anecortave acetate (AA) or (d) 2-DG plus AA (one day post AA treatment) or (e) 2-DG plus AA (one week post AA treatment). Eyes were enucleated at 21 weeks and tumor sections were analyzed for tumor burden and intra-tumoral hypoxia. Results: Combined treatment with 2-DG and AA (both 2-DG one day and one week post AA treatment) showed significant reduction in tumor burden compared to saline control (61% and 56% respectively, p <.001). Eyes treated with 2-DG one day post AA injection showed a significant tumor burden reduction as compared to 2-DG alone or 2-DG plus AA injected after one week (p<01). Further, intra-tumoral hypoxia was eliminated in 2-DG treated eyes at one day post AA injection and was significantly reduced in 2-DG eyes treated one week after AA injection (p<.0001). Conclusion: Combination focal therapy with glycolytic inhibitors and angiogenic inhibitors significantly enhanced tumor control and reduced tumor hypoxia. Treatment timing greatly impacted the effect of combined treatment. Combination therapy with 2-DG and AA was as effective as current chemotherapy regimens in the treatment of LHbetaTag murine transgenic retinoblastoma and may potentially serve as an alternative treatment strategy for advanced pediatric retinoblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4642. doi:1538-7445.AM2012-4642

Regional and temporal differences in gene expression of LH(BETA)T(AG) retinoblastoma tumors

PURPOSE

The purpose of this study was to evaluate by microarray the hypothesis that LH(BETA)T(AG) retinoblastoma tumors exhibit regional and temporal variations in gene expression.

METHODS

LH(BETA)T(AG) mice aged 12, 16, and 20 weeks were euthanatized (n = 9). Specimens were taken from five tumor areas (apex, anterior lateral, center, base, and posterior lateral). Samples were hybridized to gene microarrays. The data were preprocessed and analyzed, and genes with a P < 0.01, according to the ANOVA models, and a log(2)-fold change >2.5 were considered to be differentially expressed. Differentially expressed genes were analyzed for overlap with known networks by using pathway analysis tools.

RESULTS

There were significant temporal (P < 10(-8)) and regional differences in gene expression for LH(BETA)T(AG) retinoblastoma tumors. At P < 0.01 and log(2)-fold change >2.5, there were significant changes in gene expression of 190 genes apically, 84 genes anterolaterally, 126 genes posteriorly, 56 genes centrally, and 134 genes at the base. Differentially expressed genes overlapped with known networks, with significant involvement in regulation of cellular proliferation and growth, response to oxygen levels and hypoxia, regulation of cellular processes, cellular signaling cascades, and angiogenesis.

CONCLUSIONS

There are significant temporal and regional variations in the LH(BETA)T(AG) retinoblastoma model. Differentially expressed genes overlap with key pathways that may play pivotal roles in murine retinoblastoma development. These findings suggest the mechanisms involved in tumor growth and progression in murine retinoblastoma tumors and identify pathways for analysis at a functional level, to determine significance in human retinoblastoma. Microarray analysis of LH(BETA)T(AG) retinal tumors showed significant regional and temporal variations in gene expression, including dysregulation of genes involved in hypoxic responses and angiogenesis.

Abstract 5352: Novel treatment approaches in retinoblastoma: Impact of combination therapy on tumor burden

Purpose: The purpose of the current study is to examine vessel targeting, chemotherapy, and mammalian target of rapamycin (mTOR) inhibitor agents in LHBETATAG retinal tumors and their impact on tumor burden.

Methods: Group A: Ten-week-old, LHBETATAG mice (n=30) received a single subconjunctival injection of anecortave acetate (AA; 1200, 600, 300, and 150 µg) delivered to right eyes only. Group B: Ten-week-old, LHBETATAG mice (n=30) received a single subconjunctival injection of AA (600, 300, and 150 µg) delivered to right eyes only, either during a cycle of carboplatin (six subconjunctival deliveries) or after the completed cycle. Carboplatin was delivered at the subtherapeutic concentration of 62.5 µg. All animals were euthanatized at 16 weeks of age, and the eyes were examined histopathologically. Group C: Eighteen-week-old, LHBETATAG mice received (n=30) subconjunctival injections of rapamycin once weekly for two consecutive weeks (0.00333, 0.167, 3.33, and 6.67 mg/kg). Tumor sections were analyzed for tumor burden with immunohistochemistry techniques.

Results: A statistically significant reduction in tumor burden was detected after a single periocular injection of AA. The reduction of tumor burden followed a U-shaped dose-response curve. Tumor burden was significantly decreased when AA and carboplatin were combined. However, varying doses and delivery schedule of these agents had significant impact on the effectiveness of the combined treatment. The most effective scheme was delivering a low dose (150-300 µg) of AA after a complete cycle of carboplatin. Reduction in tumor burden were significantly different between rapamycin doses and control (p&lt;0.002). Eyes treated with rapamycin at 0.167, 3.33 and 6.67 mg/kg showed a significant decrease in tumor burden in comparison with the vehicle control group (p=0.019, p=0.001, p=0.009, respectively) and the 0.00333 mg/kg dose response (p=0.023, p=0.001, p=0.010, respectively). Histopathological evaluation showed no signs of retinal toxicity to either treatment used.

Conclusions: AA, as monotherapy or as adjuvant therapy, significantly controlled tumor burden in a murine model of retinoblastoma. Moreover, adjuvant therapy enabled the use of typically subtherapeutic carboplatin doses without decreasing efficacy of the therapy. Inhibition of mTOR reduced tumor burden during late disease in the LHBETATAG retinoblastoma tumor model. Rapamycin may have a role in combination with chemotherapy or other adjuvant therapies to enhance retinoblastoma tumor control.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5352. doi:10.1158/1538-7445.AM2011-5352

Abstract 1517: Retinoblastoma tumor development: Role of tumor-associated macrophages and their sub-type in LHBETATAG retinal tumor progression

Purpose: The purpose of the current study is to establish the distribution of tumor associated macrophages (TAMs) during tumor development in a transgenic retinoblastoma mouse model, study the contribution of bone-marrow derived macrophages in these tumors, and assess the supportive role of TAMs in retinoblastoma tumor growth.

Methods: Macrophage infiltration in transgenic retinoblastoma tumors was assessed by immunohistochemistry at different time points in tumorigenesis. To establish the origin of TAMs in transgenic retinoblastoma tumors, 107 bone marrow cells from green fluorescent protein (GFP) positive 16-week-old mice were transplanted into age-matched, irradiated LHBETATAG mice via tail vein injections. Macrophage depletion was performed by subconjuctival (SC) delivery of liposomal clodronate.

Results: TAMs’ density increased from 4- to 12-weeks of age in mice with small to medium-sized tumors (p=0.037), and remained stable in the later stages of the disease (i.e., 16-week-old with large tumors; p=0.20). 38% of TAMs (2.5 ± 3.2 cells per 400X hpf) in 16-week old mice were GFP-positive, bone marrow-derived macrophages. Total TAM depletion was correlated with a significant decrease in the expression levels of MMP-9 (p=0.014) and mature vessels (p&lt;0.001), and a nonsignificant decrease in the density of neovessels (p=0.94). The density of M2-polarized TAMs did not change significantly following TAM depletion (p=0.68). Following M1-polarized TAM depletion, the tumor burden increased (p=0.056).

Conclusions: The current study expands our understanding of the complex role that macrophages play in retinoblastoma. Macrophage modulation in the tumor microenvironment is a critical factor in retinoblastoma tumor development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1517. doi:10.1158/1538-7445.AM2011-1517

Abstract 2050: 2-Deoxy-D-Glucose (2-DG) as a glycolytic inhibitor in the treatment of retinoblastoma

Purpose: The aim of the current study is to assess the impact of the glycolytic inhibitor 2-deoxy-D-glucose (2-DG) on tumor burden and hypoxia in the LHBETATAG retinal tumors.

Methods: Group A: 17-week-old LHBETATAG transgenic mice (n=30) received periocular injections of saline and 2-DG (62.5, 125, 250, and 500mg/kg). Injections were given 2 times a week for 3 weeks. Group B: 4-week-old mice received oral delivery of 2-DG in custom made food pellets and were treated for either 8 or 18 weeks. 17-week-old mice received oral 2-DG for 8 weeks. At the time of enucleation, all eye samples were snap frozen and analyzed for tumor burden and hypoxic regions using immunohistochemistry.

Results: Following injections of 2-DG, tumor control was not different between the control and the lowest two doses (62.5 and 125mg/kg). However, the difference in tumor burden was significant from 250mg/kg dose (p&lt;0.015) and 500mg/kg dose (p&lt;0.001) with 9.7 and 23% tumor burden decrease, respectively. At all doses of periocular 2-DG, the percent hypoxia following drug treatment were lower relative to controls (p&lt;0.001), with a hypoxia decrease in the lowest dose to 2.4% compared to 21% in controls. Following oral delivery of 2-DG, there was a difference between the groups treated with 2-DG and the control groups (p&lt;0.010). A 20% reduction in tumor burden was found in the 8 weeks early treated, a 50% reduction in the 18 weeks early treated, and a 35% reduction in the 8 weeks late treated group. The percent hypoxia was lower relative to controls in the 8 weeks and 18 weeks early treated groups (p&lt;0.001) with a 40% and 50% reduction, respectively. The percent hypoxia did not change following treatment in the treated late group.

Conclusions: This study exhibits the efficacy of focal 2-DG as potential therapy to decrease both intratumoral hypoxia and tumor burden. The current study also shows that the non-invasive oral delivery 2-DG treatment has similar or better effects on the tumor depending on the treatment schedule used. In advanced disease of LHBETATAG retinal tumors, hypoxia is increasingly present. The use of glycolytic inhibitors as a therapeutic strategy has the potential to enhance current retinoblastoma treatments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2050. doi:10.1158/1538-7445.AM2011-2050

Abstract 3865: Regional and temporal variations in gene expression and vasculature during retinoblastoma tumorigenesis and its impact on ocular treatment

Purpose: The aims of this study were to evaluate the hypothesis that LHBETATAG retinoblastoma tumors exhibit regional and temporal variations in gene expression and vascular development in retinoblastoma.

Methods: To evaluate intratumoral gene expression, LHBETATAG mice aged 12, 16, and 20 weeks were euthanized (n=9). Specimens were taken from 5 tumor areas (apex, anterior lateral, center, base, and posterior lateral). Samples were hybridized with an Affymetrix GeneChip Mouse Gene ST 1.0 arrays. To examine the spatial distribution of new and mature blood vessels, immunohistochemical analyses were conducted on enucleated human (n=10) and LHBETATAG retinal tumors from 16-week-old mice (n=11).

Results: There were significant temporal differences in gene expression for LHBETATAG retinoblastoma tumors (p&lt;10-8). Genes were identified with a greater than 2.5-fold difference in expression across the three time points with variation in expression depending on region. At p&lt;0.01 and log2 fold change &gt; 2.5 there were significant changes in gene expression for 190 genes apically, 84 genes anterolaterally, 126 genes posteriorly, 56 genes centrally, and 134 genes at the base. Differentially expressed genes were analyzed with significant involvement in angiogenesis (p&lt;10-40, 4 pathways), hypoxia (p&lt;10-7, 140 pathways), and cellular metabolism (p&lt;10-8). Additionally, there were significant spatial changes in the distribution of blood vessels in human and LHBETATAG retinal tumors (p&lt;0.01), which correlated with the gene expression related to angiogenesis. The density of new blood vessels was higher in the periphery of the tumor than in the center (p=0.021) in human retinoblastoma tumors. This finding was mostly attributed to the distribution of large-caliber vessels (i.e., new blood vessels were higher in the periphery for large [p=0.050]- and medium [p=0.032]-caliber vessels; and mature vessels were higher in the center for large-caliber vessels [p=0.032]). In this small series, vessel maturation did not correlate with risk for metastasis. Similar results were observed in LHBETATAG retinal tumors. The percentage of large-caliber new blood vessels was higher in the periphery than in the center (p=0.038).

Conclusions: There are significant temporal and regional variations in the gene expression and vasculature of retinoblastoma. Differentially expressed genes overlap with angiogenesis, hypoxia, and cellular metabolism. There is a heterogeneous vessel population in advanced retinoblastoma disease. These findings provide further understanding of the mechanisms involved in tumor progression, and emphasize that tumor biopsies cannot be used for prognostication secondary to tumor regionalization. Finally, optimally-timed adjuvant therapies that target critical components of identified pathways may potentially enhance retinoblastoma tumor control.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3865. doi:10.1158/1538-7445.AM2011-3865

Clinical imaging and high-resolution ultrasonography in melanocytoma management

Purpose:

To demonstrate the utility of high resolution 20 MHz ophthalmic ultrasound in serial follow-up of optic nerve head melanocytoma patients.

Methods:

This study is a retrospective review of 30 patients with melanocytoma of the optic nerve head studied with echography. All patients were evaluated with standard ophthalmic A-scan and B-scan ultrasonography and 10 (33%) underwent high-resolution ultrasound.

Results:

Sixty-two percent (62%) of patients had dome-shaped lesions on ultrasound, twenty-eight percent (28%) presented with mild elevations. The maximum elevation of any lesion was 2.6 mm. The vast majority (89%) of lesions had medium or high internal reflectivity and 89% demonstrated avascularity. Mean follow-up for all patients was nearly 7 years. High-resolution ultrasound enabled enhanced accuracy for detection of lesion dimensions and documentation of growth and possible malignant transformation.

Conclusions:

In this study, we demonstrate a new and important role for the use of ultrasound in this disease as a complementary tool in identifying and following patients with high-risk growth characteristics. These tumor characteristics can be accurately detected with 10 MHz ultrasound in conjunction with standardized A-scan and better differentiated with the 20 MHz technology. Use of these modalities can aid in distinguishing the melanocytomas that grow from choroidal melanomas and can prevent unnecessary treatments.

Quantitative enumeration of vascular smooth muscle cells and endothelial cells derived from bone marrow precursors in experimental choroidal neovascularization

Choroidal neovascularization (CNV) is characterized by the subretinal invasion of a pathologic new vessel complex from the choriocapillaris. Although CNV is traditionally considered to consist of endothelial cells, the cellular population of CNV is likely more complex in nature, comprising several different cell types. In addition, recent studies suggest that the CNV cell population has a dual origin (circulating versus resident populations). In this study we sought to determine the contribution and origin of different cell types in experimental CNV. Laser-induced CNV was performed on chimeric mice generated by reconstituting C57BL/6 mice with bone marrow from green fluorescent protein (GFP)-transgenic mice. In these mice, bone marrow-derived cells are GFP-labeled. Immunofluorescence staining was used to examine both flatmount preparations of the choroid and cross sections of the posterior pole for macrophages, endothelial cells, vascular smooth muscle cells, retinal pigment epithelial (RPE) cells, lymphocytes, or neutrophils at day 3, 7, 14 and 28 post-laser (n=5 per group). Cell types present in CNV included macrophages (20% of the cells in CNV), endothelial cells (25%), vascular smooth muscle cells (11%), RPE cells (12%) and non-labeled cells (32%). The macrophage population was mostly derived from circulating monocytes at all timepoints studied (70% were GFP labeled), while endothelial and vascular smooth muscle cells were partly bone marrow derived (50-60% were GFP labeled), and RPE cells appeared to be entirely derived from preexisting tissue resident cells. These results demonstrate that bone marrow-derived progenitor cells contribute significantly to the vascular and inflammatory components of CNV. Knowledge of the cellular composition and origin might help understand the pathogenic mechanisms controlling CNV severity as well as indicate potential targets for therapeutic intervention.