Liquid biopsy for improving diagnosis and monitoring of CNS lymphomas: a RANO review.

BACKGROUND: The utility of liquid biopsies is well documented in several extracranial and intracranial (brain/leptomeningeal metastases, gliomas) tumors. METHODS: The RANO (Response Assessment in Neuro-Oncology) group has set up a multidisciplinary Task Force to critically review the role of blood and CSF-liquid biopsy in central nervous system lymphomas, with a main focus on primary central nervous system lymphomas (PCNSL). RESULTS: Several clinical applications are suggested: diagnosis of PCNSL in critical settings (elderly or frail patients, deep locations, steroids responsiveness), definition of minimal residual disease, early indication of tumor response or relapse following treatments and prediction of outcome. CONCLUSIONS: Thus far, no clinically validated circulating biomarkers for managing both primary and secondary CNS lymphomas exist. There is need of standardization of biofluid collection, choice of analytes and type of technique to perform the molecular analysis. The various assays should be evaluated through well organized central testing within clinical trials.

Stereotactic Radiosurgery for Primary Central Nervous System Lymphoma.

Background Primary central nervous system lymphoma (PCNSL) is rare, with a treatment backbone that typically includes high-dose methotrexate-based chemotherapy, with radiation often reserved for persistent or progressive disease. In this study, we report the outcomes of stereotactic radiosurgery (SRS) in patients with PCNSL to potentially defer whole brain radiotherapy (WBRT) or as salvage after WBRT. Methodology We performed a single-institution, retrospective review of 20 patients with PCNSL who received single-fraction or fractionated SRS to 32 lesions between September 1992 and July 2019. Results The median age at SRS was 67 years (interquartile range (IQR) = 56-74 years). The median Karnofsky Performance Status (KPS) at SRS was 80 (IQR = 50-80). In total, 18 (90%) patients received methotrexate-based chemotherapy prior to SRS, with a median of eight cycles (IQR = 5-10). A total of 10 patients received SRS for recurrent disease after chemotherapy and/or WBRT, nine patients received SRS for the persistent disease after chemotherapy alone, and one patient received up-front SRS. Overall, five patients received SRS following WBRT. The median SRS dose was 16 Gy (IQR = 14-22.5 Gy) in one fraction (IQR = 1-5 fractions). Eight patients (40%) were treated with consolidative pomalidomide or lenalidomide following SRS. The local control rate was 100% (32/32 lesions at a median follow-up of 15 months). In total, 13 of 16 (81%) patients with available follow-up experienced distant brain recurrence. The median time to distant failure following SRS was 10 months (IQR = 1-16 months). Three patients received salvage SRS, and three patients received salvage WBRT. The median overall survival from diagnosis was 39 months (95% confidence interval = 24-54 months). KPS at the time of SRS was significantly correlated with time to progression (p = 0.002). The use of lenalidomide or pomalidomide after SRS was associated with improved overall survival after SRS (three vs. 14 months, p = 0.035). Consolidative etoposide and cytarabine after initial methotrexate-based chemotherapy was also associated with improved survival following SRS (eight vs. 47 months, p = 0.028). Conclusions SRS offers effective local tumor control for patients with PCNSL; however, the majority of patients experience distant progression. SRS may have a role in the salvage setting for patients with recurrence after WBRT, or allow deferral of WBRT in select patients, although systemic therapy appears to strongly influence outcomes in this cohort.

EBV-positive PCNSL in older patients: incidence, characteristics, tumor pathology, and outcomes across a large multicenter cohort.

The objective of this multicenter retrospective study was to examine the incidence, patient characteristics, pathology, and outcomes associated with Epstein-Barr virus (EBV)-related CNS lymphoma (CNSL) in older patients. Among 309 CNSL patients aged ≥60, 11.7% had EBV + tumors of which 72.2% were solid organ transplant (SOT)-related post-transplant lymphoproliferative disorders (PTLD). Younger age, SOT or autoimmune disease, and immunosuppressive treatment correlated highly with EBV-positivity. EBV + tumors were associated with absent C-MYC and BCL6 expression. EBV + PTLD was more likely to be associated with the absence of CD5 expression. EBV + non-PTLD had better median OS (not reached) compared to EBV + PTLD (10.8 months) and EBV-negative patients (43 months). Multivariable Cox regression analysis showed that age, performance status, and PTLD were negative predictors of OS. EBV status and immunosuppressive treatment were not correlated with OS. Our findings merit further investigation of EBV + PCNSL tumors and EBV-directed therapies.

Primary CNS lymphoma: update on molecular pathogenesis and therapy.

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin lymphoma that as a brain tumor poses a unique set of challenges in diagnosis and management. With the advent of next-generation sequencing, we review updates in the understanding of its molecular and genomic pathogenesis. We also highlight key issues in management, with a focus on emerging technologies and new biological therapies including monoclonal antibodies, IMiDs, BTK inhibitors, PD-1 inhibitors, and CAR-T therapy. Integration of these approaches will likely enhance induction and consolidation strategies to suppress NF-κB activation and the anti-tumor immune response, while minimizing the often noxious effects of genotoxic approaches.

Acquired factor VII inhibitor associated with primary central nervous system Lymphoma: A case report.

Paraneoplastic coagulopathies are uncommon in patients with lymphoma. We report the first case of an acquired coagulopathy in a patient with isolated primary central nervous system lymphoma (PCNSL) demonstrating large-cell histology. In our patient, a paraneoplastic factor VII inhibitor significantly delayed a diagnostic lumbar puncture despite fresh frozen plasma and inactivated prothrombin complex concentrate. While her coagulopathy was effectively overcome with recombinant activated factor VIIa and subsequently with lymphoma-directed therapy, her delayed diagnosis likely contributed to a poor outcome. Our case highlights the importance of rapidly identifying and correcting paraneoplastic coagulopathies when PCNSL is suspected.

Primary CNS Lymphoma: Progress With Dose-Intensive Consolidation.

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

A functional mammalian display screen identifies rare antibodies that stimulate NK cell-mediated cytotoxicity.

Therapies that boost the antitumor immune response have shown a great deal of success. Although most of these therapies have focused on enhancing T cell functions, there is a growing interest in developing therapies that can target other immune cell subsets. Like T cells, natural killer (NK) cells are cytotoxic effector cells that play a key role in the antitumor response. To advance the development of NK-based therapies, we developed a functional screen to rapidly identify antibodies that can activate NK cells. We displayed antibodies on a mammalian target cell line and probed their ability to stimulate NK cell-mediated cytotoxicity. From this screen, we identified five antibodies that bound with high affinity to NK cells and stimulated NK cell-mediated cytotoxicity and interferon-γ (IFN-γ) secretion. We demonstrate that these antibodies can be further developed into bispecific antibodies to redirect NK cell-mediated cytotoxicity toward CD20+ B cell lymphoma cells and HER2+ breast cancer cells. While antibodies to two of the receptors, CD16 and NCR1, have previously been targeted as bispecific antibodies to redirect NK cell-mediated cytotoxicity, we demonstrate that bispecific antibodies targeting NCR3 can also potently activate NK cells. These results show that this screen can be used to directly identify antibodies that can enhance antitumor immune responses.

Tumor metabolism and neurocognition in CNS lymphoma.

BACKGROUND: The mechanistic basis for neurocognitive deficits in central nervous system (CNS) lymphoma and other brain tumors is incompletely understood. We tested the hypothesis that tumor metabolism impairs neurotransmitter pathways and neurocognitive function. METHODS: We performed serial cerebrospinal fluid (CSF) metabolomic analyses using liquid chromatography-electrospray tandem mass spectrometry to evaluate changes in the tumor microenvironment in 14 patients with recurrent CNS lymphoma, focusing on 18 metabolites involved in neurotransmission and bioenergetics. These were paired with serial mini-mental state examination (MMSE) and MRI studies for tumor volumetric analyses. Patients were analyzed in the setting of the phase I trial of lenalidomide/rituximab. Associations were assessed by Pearson and Spearman correlation coefficient. Generalized estimating equation (GEE) models were also established, adjusting for within-subject repeated measures. RESULTS: Of 18 metabolites, elevated CSF lactate correlated most strongly with lower MMSE score (P < 8E-8, ρ = -0.67). High lactate was associated with lower gamma-aminobutyric acid (GABA), higher glutamate/GABA ratio, and dopamine. Conversely, high succinate correlated with higher MMSE scores. Serial analysis demonstrated a reproducible, time-dependent, reciprocal correlation between changes in lactate and GABA concentrations. While high lactate and low GABA correlated with tumor contrast-enhancing volume, they correlated more significantly with lower MMSE scores than tumor volumes. CONCLUSIONS: We provide evidence that lactate production and Warburg metabolism may impact neurotransmitter dysregulation and neurocognition in CNS lymphomas. We identify novel metabolomic biomarkers that may be applied in future studies of neurocognition in CNS lymphomas. Elucidation of mechanistic interactions between lymphoma metabolism, neurotransmitter imbalance, and neurocognition may promote interventions that preserve cognitive function.

Blood Coagulation Factor Fibrinogen in Tumor Pathogenesis of Central Nervous System B-Cell Lymphoma.

Central nervous system (CNS) lymphoma is an extranodal non-Hodgkin B-cell lymphoma characterized by malignant lymph tissue arising in the brain or spinal cord, associated with inflammation and blood-brain barrier (BBB) disruption. Although BBB disruption is known to occur in patients with CNS lymphoma, a direct link between these two has not been shown. Herein, abundant deposition of the blood coagulation protein fibrinogen around B-cell lymphoma was detected in CNS lymphoma patients and in the CNS parenchyma in an orthotopic mouse model. Functional enrichment analysis of unbiased cerebrospinal fluid proteomics of CNS B-cell lymphoma patients showed that coagulation protein networks were highly connected with tumor-associated biological signaling pathways. In vivo two-photon imaging demonstrated that lymphoma growth was associated with BBB disruption, and in vitro experiments identified a role for fibrinogen in promoting lymphoma cell adhesion. Overall, these results identify perivascular lymphoma clustering at sites of fibrinogen deposition, and suggest that fibrinogen may be a target for pharmacologic intervention in metastatic B-cell lymphoma associated with BBB disruption.

Consensus recommendations for MRI and PET imaging of primary central nervous system lymphoma: guideline statement from the International Primary CNS Lymphoma Collaborative Group (IPCG).

Advanced molecular and pathophysiologic characterization of primary central nervous system lymphoma (PCNSL) has revealed insights into promising targeted therapeutic approaches. Medical imaging plays a fundamental role in PCNSL diagnosis, staging, and response assessment. Institutional imaging variation and inconsistent clinical trial reporting diminishes the reliability and reproducibility of clinical response assessment. In this context, we aimed to: (1) critically review the use of advanced positron emission tomography (PET) and magnetic resonance imaging (MRI) in the setting of PCNSL; (2) provide results from an international survey of clinical sites describing the current practices for routine and advanced imaging, and (3) provide biologically based recommendations from the International PCNSL Collaborative Group (IPCG) on adaptation of standardized imaging practices. The IPCG provides PET and MRI consensus recommendations built upon previous recommendations for standardized brain tumor imaging protocols (BTIP) in primary and metastatic disease. A biologically integrated approach is provided to addresses the unique challenges associated with the imaging assessment of PCNSL. Detailed imaging parameters facilitate the adoption of these recommendations by researchers and clinicians. To enhance clinical feasibility, we have developed both "ideal" and "minimum standard" protocols at 3T and 1.5T MR systems that will facilitate widespread adoption.

Primary central nervous system lymphoma in older adults and the rationale for maintenance strategies: a narrative review.

OBJECTIVE: To provide a summary and analysis of the evidence for various agents applied as maintenance therapy and highlight ongoing trials or trials in development that evaluate the efficacy of maintenance therapy strategies in older patients with primary central nervous system lymphoma (PCNSL). BACKGROUND: PCNSL are rare neoplasms that can have an aggressive course with short-lived remissions when compared to systemic diffuse large B-cell lymphoma (DLBCL). There is currently a paucity of evidence on treatment in older adults with PCNSL, who may be unfit to tolerate effective therapies for PCNSL. Those who can tolerate these therapies and survive PCNSL are at increased risk from developing treatment-related toxicity, functional decline, and debilitating neurotoxicity. While there is no clearly defined role for maintenance therapy after treatment of systemic DLBCL, it should be considered in PCNSL because central nervous system (CNS) recurrence often has a devastating and irreversible impact on neurologic function. Therefore, at least theoretically, use of effective maintenance therapy in older adults with PCNSL, either in lieu of consolidation or after consolidation therapy, may be better tolerated and help delay tumor progression, resulting in an improved overall global neurologic function and quality of life. METHODS: We systematically searched MEDLINE (via PubMed) for all studies of drug treatments for maintenance therapy in PCNSL and also relied on expert opinion. We provide a summary and analysis of the evidence for various maintenance therapy agents, including methotrexate, rituximab, lenalidomide, temozolomide, ibrutinib, and procarbazine. We also highlight ongoing trials or trials in development that evaluate the efficacy of maintenance therapy in PCNSL. CONCLUSIONS: Prospective clinical studies focusing on PCNSL patients who are not candidates for intensive post-induction therapy are scarce. To date, there are no studies that clarify whether maintenance therapy can be used in lieu of consolidation therapy with autologous stem cell transplant or radiation. Prospective studies may provide critical data regarding the identification of optimal agents, whether consolidation therapy could be replaced by maintenance therapy, and the overall role of maintenance therapy as a means to potentially improve survival and preserve quality of life and function in a vulnerable, older patient population.

On point in primary CNS lymphoma.

Primary CNS lymphoma (PCNSL) is an aggressive brain tumor that represents a significant challenge both to elucidate its biological pathogenesis as well as to develop definitive precision medicines with minimal collateral toxicity. We highlight the key issues in diagnosis and treatment and focus on emerging technologies, current options among consolidation strategies, and biological agents. We anticipate that further development of molecular diagnostics and molecular imaging approaches that elucidate minimal residual disease in brain parenchyma, leptomeninges, intraocular compartments and even bone marrow will greatly impact the delivery and timing of cytotoxic and biological therapies. Implementation of these approaches is likely essential to clarify ongoing discrepancies in the interpretation of clinical trial results that currently are based on relatively unrefined definitions of response. While the results of early phase investigations involving ibrutinib and the IMiD agents, lenalidomide, pomalidomide, as well as avadomide, strongly support the hypothesis that the B-cell receptor (BCR) pathway, involving MYD88 and CD79B and NF-kB activation, is critical to the pathogenesis of PCNSL, much work is needed to elucidate mechanisms of resistance. Similarly, development of strategies to overcome immunosuppressive mechanisms that are upregulated in the tumor microenvironment is a high priority. Finally, ongoing evidence supports the hypothesis that the blood-brain barrier represents a significant impediment to efficient brain tumor penetration of novel therapeutic agents and innovative strategies of drug delivery remain essential to further improve outcomes.

An audit of retinal lymphoma treatment at the University of California San Francisco.

BACKGROUND/OBJECTIVES: To evaluate retinal lymphoma treatment at the University of California San Francisco. SUBJECTS/METHODS: Prospective observational audit. Patients were treated systemically, usually with: methotrexate, temozolomide, and rituximab induction; etoposide consolidation; and maintenance with lenalidomide or another immunomodulatory agent. Persistent disease was treated initially by ocular radiotherapy or intravitreal melphalan and latterly by vitrectomy. RESULTS: The cohort comprised eight females and two males. The median age was 58 years (range, 38-73). Ocular manifestations were initially unilateral in four patients. Vitreous and subretinal infiltrates were initially present in 16 and 12 eyes, respectively, with three eyes having vision of 20/200 or worse. Four patients had a history of central nervous system (CNS) lymphoma. The median ophthalmic follow-up was 37 months (range, 8-56). Diagnostic and therapeutic vitrectomy were performed in 10 and 2 eyes, respectively. All patients had systemic chemotherapy and eight received maintenance immunotherapy. Four patients underwent ocular radiotherapy, bilaterally in two. One patient received bilateral intravitreal melphalan injections. Two eyes of four patients developed lymphoma during the study and two patients developed CNS disease. At study close, subretinal deposits were subtle in nine eyes and more prominent in two, whereas vitreous infiltrates were minimal in nine eyes, mild in one and moderate in one. The latest visual acuity was significantly worse than at presentation in two eyes and better in two. All patients were alive with no active CNS disease. CONCLUSIONS: Subretinal lymphomatous infiltrates respond to systemic chemotherapy with immunomodulatory maintenance, but dense vitreous infiltrates require therapeutic vitrectomy.

THERAPEUTIC VITRECTOMY AS AN ADJUNCT TREATMENT TO SYSTEMIC CHEMOTHERAPY FOR INTRAOCULAR LYMPHOMA.

PURPOSE: To report the outcome of a previously vitrectomized eye having less lymphoma disease burden compared with the contralateral nonvitrectomized eye over the course of 3.5 years while on systemic chemotherapy. METHODS: Case report. RESULTS: A 51-year-old man with vitreoretinal lymphoma with central nervous system involvement underwent vitrectomy in his left eye. Over the following 3.5 years on systemic chemotherapy, the left eye had less lymphoma disease burden compared with the contralateral nonvitrectomized right eye. CONCLUSION: Therapeutic vitrectomy may be a useful adjunct to systemic chemotherapy in vitreoretinal lymphoma, particularly in cases of vitreous predominant disease manifestation.

Evolving Treatments for Primary Central Nervous System Lymphoma.

Primary central nervous system (CNS) lymphoma (PCNSL) is an aggressive form of non-Hodgkin lymphoma that remains confined to the CNS neuroaxis during its natural history of disease and is therefore considered stage IE disease. PCNSL is diffuse large B-cell lymphoma (DLBCL) morphology in more than 95% of patients and is designated primary diffuse large B-cell lymphoma of the CNS on the basis of the 2017 World Health Organization classification of hematopoietic and lymphoid tumors. Rapidly evolving therapeutic paradigms have been linked to evidence of progress in PCNSL, a disease long considered to be incurable. Increasing evidence supports the need for efficient diagnosis, staging, and initiation of therapy, ideally at centers with experience with this type of brain cancer. High-dose methotrexate (MTX) remains a cornerstone of induction regimens, and most data support the use of rituximab. However, clinical research challenges must address key questions, including the development of ever more effective and less toxic induction regimens and the selection of the most appropriate and effective consolidation approaches, as well as the fact that, increasingly, PCNSL affects older patients who do not tolerate strong genotoxic irradiation or high-dose chemotherapy (HDC)-based strategies. Maintenance therapy, immunotherapy, and the implementation of targeted agents on the basis of the molecular and biologic properties of the disease create opportunities for precision medicine and the potential for long-term disease-free survival and cure, with minimal treatment-related neurotoxicity, for a greater fraction of patients.

Insights from a Case of Vitreoretinal Lymphoma.

PURPOSE/BACKGROUND: The aim of this study was to report a patient with vitreoretinal lymphoma with clinical features providing hypothesis-generating insights into the pathophysiology of this disease. METHODS: Clinical history and imaging studies (i.e., fundus photography, optical coherence tomography, fundus autofluorescence, and fluorescein angiography) were documented. RESULTS: A 71-year-old woman presented with a 2-month history of blurred vision in the right eye and bilateral vitreous infiltrates unresponsive to topical and systemic steroids. Vitreous biopsy of the left eye was diagnostic for lymphoma. Bulky subretinal deposits in the right eye responded to systemic therapy. The left fundus showed diffuse hypoautofluorescence and punctate, hyperfluorescent sub-retinal pigment epithelial tumor deposits, which resolved leaving hypoautofluorescent atrophic retinal pigment epithelium (RPE) scars, except inferotemporally, where retinal vasculopathy had occurred. CONCLUSIONS: The clinical features suggest that occlusion of the inferotemporal retinal arteriole prevented sub-RPE lymphomatous deposits and subsequent RPE atrophy in this area of vascular nonperfusion. This suggests that "primary" vitreoretinal lymphoma is secondary to hematogenous spread from systemic loci. This finding, together with the ocular tumor control achieved entirely by systemic therapy, indicates scope for studies investigating systemic treatment protocols, especially those including immune-modulatory agents.