Second-line treatment for primary central nervous system lymphoma

Imaging Features of Immunodeficiency-Associated Primary CNS Lymphoma: A Review

In the immunocompromised setting, there are distinct radiologic findings of primary central nervous system lymphoma (PCNSL), including necrotic ring-enhancing lesions, increased propensity for intralesional haemorrhage, and multiplicity. In this clinical context, advanced imaging with MR perfusion, spectroscopy, and diffusion-weighted imaging can be used to increase accuracy in the diagnosis of lymphoma over mimics such as high-grade glioma, metastases, or infection. This review summarizes the histology and pathophysiology of PCNSL in immunodeficient hosts, which provide a basis for its imaging appearances, prognosis, and treatment. This discussion is important for the general radiologist as the incidence of immunodeficiency-related PCNSL may be increasing.

Bruton's tyrosine kinase inhibitor zanubrutinib-based regimens in relapsed/refractory primary diffuse large B-cell lymphoma of the central nervous system

Patients with relapsed/refractory primary central nervous system lymphoma (R/R PCNSL) usually have a poor prognosis and limited treatment options. We respectively reviewed 38 patients with R/R PCNSL treated with zanubrutinib-based regimens in our center. The overall response rate, complete response rate and disease control rate were 76.3%, 47.4% and 92.1%, respectively. The median progression-free survival (PFS) was 31.0 months, the median overall survival (OS) was not reached. Unitivariate analysis by Cox's proportional hazards model revealed that overall response (vs. no response, HR = 0.18, 95%CI:0.07,0.48, p = 0.001), long duration of zanubrutinib (≥6months vs 2-5 months, HR = 0.20, 95%CI:0.06,0.63, p = 0.006) were independent factors for prolonged PFS. The log-rank analysis indicated a prolongation of PFS among patients exhibiting a higher Tumor mutational burden (TMB, ≥14.75muts/Mb) following zanubrutinib-based treatment (p = 0.016). Our data showed promising efficacy with tolerable safety of zanubrutinib-based therapies in patients with R/R PCNSL. Long duration of zanubrutinib may be associated with prolonged PFS.

Outcomes and relapse patterns in primary central nervous system lymphoma: Longitudinal analysis of 559 patients diagnosed from 1983 to 2020

BACKGROUND

Contemporary outcomes and relapse patterns in primary CNS lymphoma (PCNSL) are lacking. We analyzed factors associated with relapse in a large cohort with extensive follow-up.

METHODS

T1-post-contrast-enhancing disease was characterized in immunocompetent PCNSL (diffuse large B-cell) patients from 1983 to 2020. Patients were stratified by response to induction and consolidation (complete/unconfirmed [CR/CRu], partial, stable, progression [POD]). Refractory was POD during (or relapse ≤3 months of) induction. Initial relapse site was categorized as local (involving/adjacent to baseline), distant intraparenchymal, leptomeningeal, or other. Progression-free (PFS) and overall survival (OS) were assessed with proportional hazards. Cumulative incidence with competing risks was used to assess local relapse.

RESULTS

Median follow-up was 7.4 years (N = 559). Most (321, 57%) were recursive partitioning analysis class 2 (age ≥50, Karnosfky Performance Status [KPS] ≥70). Most had supratentorial (420, 81%), multifocal (274, 53%), bilateral (224, 43%), and deep structure involvement (314, 56%). Nearly all received methotrexate-based induction (532, 95%). There was no difference in PFS or OS from consolidation based on initial response to induction (CR/CRu vs PR) in patients who ultimately achieved a CR/CRu to consolidation. PFS at 1-, 5 years for 351 patients with CR/CRu to consolidation was 80% (95% confidence interval [95% CI]: 76%-84%) and 46% (95% CI: 41%-53%), respectively; 1-year cumulative incidence of local versus nonlocal relapse was 1.8% versus 15%, respectively. For 97 refractory patients, 1-year cumulative incidence of local versus nonlocal relapse was 57% versus 42%, respectively. Deep structure involvement (HR 1.89, 95% CI: 1.10%-3.27%) was associated with local relapse in refractory patients.

CONCLUSIONS

We report the first comprehensive relapse patterns in a large PCNSL cohort. While relapses post-CR to consolidation are typically distant and unpredictable, refractory patients had a relatively high incidence of local relapse. These findings can help optimize multimodality therapy for this highest-risk population.

Machine learning-based pathomics signature of histology slides as a novel prognostic indicator in primary central nervous system lymphoma

PURPOSE

To develop and validate a pathomics signature for predicting the outcomes of Primary Central Nervous System Lymphoma (PCNSL).

METHODS

In this study, 132 whole-slide images (WSIs) of 114 patients with PCNSL were enrolled. Quantitative features of hematoxylin and eosin (H&E) stained slides were extracted using CellProfiler. A pathomics signature was established and validated. Cox regression analysis, receiver operating characteristic (ROC) curves, Calibration, decision curve analysis (DCA), and net reclassification improvement (NRI) were performed to assess the significance and performance.

RESULTS

In total, 802 features were extracted using a fully automated pipeline. Six machine-learning classifiers demonstrated high accuracy in distinguishing malignant neoplasms. The pathomics signature remained a significant factor of overall survival (OS) and progression-free survival (PFS) in the training cohort (OS: HR 7.423, p < 0.001; PFS: HR 2.143, p = 0.022) and independent validation cohort (OS: HR 4.204, p = 0.017; PFS: HR 3.243, p = 0.005). A significantly lower response rate to initial treatment was found in high Path-score group (19/35, 54.29%) as compared to patients in the low Path-score group (16/70, 22.86%; p < 0.001). The DCA and NRI analyses confirmed that the nomogram showed incremental performance compared with existing models. The ROC curve demonstrated a relatively sensitive and specific profile for the nomogram (1-, 2-, and 3-year AUC = 0.862, 0.932, and 0.927, respectively).

CONCLUSION

As a novel, non-invasive, and convenient approach, the newly developed pathomics signature is a powerful predictor of OS and PFS in PCNSL and might be a potential predictive indicator for therapeutic response.

Long-term survival after salvage pemetrexed for refractory primary T-cell lymphoma of the CNS

Primary T-cell CNS lymphoma is a rare and aggressive malignancy. High-dose methotrexate (MTX) based chemotherapy regimens are used as standard first-line treatment, followed by consolidative strategies to improve the duration of response. Although MTX-based therapy has been shown to be efficacious, treatment options for MTX-refractory disease are not well-defined. Here, we report a case of a 38-year-old man with refractory primary T-cell CNS lymphoma who demonstrated a complete response to pemetrexed treatment. He subsequently received conditioning chemotherapy consisting of thiotepa, busulfan and cyclophosphamide followed by autologous stem cell transplantation. The patient continues to remain recurrence-free to date at 9 years post-treatment.

Is CD19-directed chimeric antigen receptor T cell therapy a smart strategy to combat central nervous system lymphoma?

Primary central nervous system lymphoma (PCNSL) is a rare form and aggressive type of diffuse large B-cell lymphoma (DLBCL) that occurs in both immunocompetent and immunocompromised adults. While adding rituximab to chemotherapeutic regimens resulted in dramatic improvement in both progression-free survival and overall survival in patients with non-central nervous system (CNS) DLBCL, the outcomes of PCNSL are generally poor due to the immune-privileged tumor microenvironment or suboptimal delivery of systemic agents into tumor tissues. Therefore, more effective therapy for PCNSL generally requires systemic therapy with sufficient CNS penetration, including high-dose intravenous methotrexate with rituximab or high-dose chemotherapy followed by autologous stem cell transplantation. However, overall survival is usually inferior in comparison to non-CNS lymphomas, and treatment options are limited for elderly patients or patients with relapsed/refractory disease. Chimeric antigen receptor T (CAR-T) cell therapy has emerged as a cutting-edge cancer therapy, which led to recent FDA approvals for patients with B-cell malignancies and multiple myeloma. Although CAR-T cell therapy in patients with PCNSL demonstrated promising results without significant toxicities in some small cohorts, most cases of PCNSL are excluded from the pivotal CAR-T cell trials due to the concerns of neurotoxicity after CAR-T cell infusion. In this review, we will provide an overview of PCNSL and highlight current approaches, resistance mechanisms, and future perspectives of CAR-T cell therapy in patients with PCNSL.

Cerebrospinal fluid metabolic markers predict prognosis behavior of primary central nervous system lymphoma with high-dose methotrexate-based chemotherapeutic treatment

Background

Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin's B-cell lymphoma which normally treated by high-dose methotrexate (HD-MTX)-based chemotherapy. However, such treatment cannot always guarantee a good prognosis (GP) outcome while suffering several side effects. Thus, biomarkers or biomarker-based models that can predict PCNSL patient prognosis would be beneficial.

Methods

We first collected 48 patients with PCNSL and applied HPLC-MS/MS-based metabolomic analysis on such retrospective PCNSL patient samples. We then selected the highly dysregulated metabolites to build a logical regression model that can distinguish the survival time length by a scoring standard. Finally, we validated the logical regression model on a 33-patient prospective PCNSL cohort.

Results

Six metabolic features were selected from the cerebrospinal fluid (CSF) that can form a logical regression model to distinguish the patients with relatively GP (Z score ≤0.06) from the discovery cohort. We applied the metabolic marker-based model to a prospective recruited PCNSL patient cohort for further validation, and the model preformed nicely on such a validation cohort (AUC = 0.745).

Conclusions

We developed a logical regression model based on metabolic markers in CSF that can effectively predict PCNSL patient prognosis before the HD-MTX-based chemotherapy treatments.

Analysis of Key Factors Associated with Response to Salvage High-Dose Methotrexate Rechallenge in Primary Central Nervous System Lymphoma with First Relapse

Background: Primary central nervous system lymphoma (PCNSL) is a rare extranodal non-Hodgkin’s lymphoma that occurs in the central nervous system. Although sensitive to chemotherapy, 35–60% of PCNSL patients still relapse within 2 years after the initial treatment. High-dose methotrexate (HD-MTX) rechallenge is generally used in recurrent PCNSL, especially for patients who have achieved a response after initial methotrexate (MTX) treatment. However, the overall remission rate (ORR) of HD-MTX rechallenge is about 70–80%. Additionally, the side effects of HD-MTX treatment endanger the health of patients and affect their quality of life. Methods: This is a retrospective study of patients with first relapse PCNSL at Huashan Hospital, Fudan University between January 2000 and November 2020. By comparing the clinical characteristics and radiological manifestations of first relapsed PCNSL patients with remission and non-remission after receiving HD-MTX rechallenge, we screened out the key factors associated with HD-MTX rechallenge treatment response, to provide some help for the selection of salvage treatment strategies for patients with recurrent PCNSL. Additionally, patients with remission after HD-MTX rechallenge were followed up to identify the factors related to progression-free survival of the second time (PFS2) (time from the first relapse to second relapse/last follow-up). The Kruskal–Wallis and Pearson chi-square tests were performed to examine the univariate association. Further, multivariable logistic regression analysis was used to study the simultaneous effect of different variables. Results: A total of 207 patients were enrolled in the study based on the inclusion criteria, including 114 patients in the remission group (RG) and 81 patients in the non-remission group (nRG), and 12 patients were judged as having a stable disease. In Kruskal–Wallis and Pearson chi-square tests, progression-free survival rates for first time (PFS1) and whether the initial treatment was combined with consolidated whole brain radiotherapy (WBRT) were related to the response to HD-MTX rechallenge treatment, which was further validated in regression analysis. Further, after univariate analysis and regression analysis, KPS was related to PFS2. Conclusions: For PCNSL patients in their first relapse, HD-MTX rechallenge may be an effective salvage treatment. PFS1 and whether initial treatment was combined with consolidation WBRT were associated with HD-MTX rechallenge treatment response. In addition, patients with higher KPS at the time of the first relapse had a longer PFS2 after HD-MTX rechallenge treatment.

Pemetrexed Plus Lenalidomide for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Prospective Single-Arm Phase II Study

The prognosis of relapsed/refractory (R/R) primary central nervous system lymphoma (PCNSL) is dismal, and there are limited treatment options for these patients. This was a prospective single-arm phase II study of combined pemetrexed and lenalidomide for salvage treatment of R/R PCNSL. Patients with R/R PCNSL (n = 38) who had undergone two or more different therapeutic regimens and experienced disease progression or recurrence were enrolled. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Patients were followed up for a median of 18 (range, 1–36) months. ORR was 68.4%, with median PFS and OS of 6 and 18 months, respectively. Adverse events (AEs) included myelosuppression, fatigue, nausea, fever, infection, cardiac disease, and thrombogenesis. Commonly observed grade ≥ 3 AEs included neutropenia (5.3%), leukopenia (2.6%), thrombocytopenia (7.9%), and infection (2.6%). Elevated lactate dehydrogenase (LDH) levels (χ2 = 13.25; P = 0.0003) and bulky disease (P = 0.032; χ2 = 4.580) were associated with short PFS. Elevated serum LDH level (P = 0.011; χ2 = 6.560), abnormal lymphoma cells in the cerebrospinal fluid (CSF) [P = 0.011; χ2 = 6.445], and multiple lesions (P = 0.036; χ2 = 4.404) were significantly associated with poorer OS. Abnormal lymphoma cells in the CSF were an independent predictor of poor prognosis on multivariate analysis (P = 0.034; hazard ratio (HR) = 2.836; 95% confidence interval, 1.082–7.434). Our results indicate that pemetrexed plus lenalidomide is effective for heavily treated R/R PCNSL, with moderate toxicity. Trial registration: #ChiCTR1900028070.

Rituximab, Methotrexate, Carmustine, Etoposide, and Prednisone (RMBVP) for the treatment of relapsed/refractory primary central nervous system lymphoma: a retrospective single-center study

Relapsed/refractory Primary Central Nervous System Lymphoma (R/R PCNSL) has a poor prognosis with no established preferred treatment. We report the efficacy and toxicity of a combination chemotherapy regimen: methotrexate, carmustine, etoposide, and prednisone with or without rituximab (RMBVP). This retrospective study included thirty patients who received a median of two 28-day cycles (0.5-5). The median age was 66 years (23-81); median KPS was 70 (30-90); 14 (46.7%) were women. Patients received a median of 2 prior lines of therapy and all received prior methotrexate. Of 29 evaluable patients, the overall response rate was 73.3% (n = 22). Median progression-free survival (PFS) was 15.6 months. Patients who recurred or progressed <12 months since last chemotherapy had a shorter median PFS (7.6 vs 37.6 months). Toxicity was moderate with 20% rates of severe myelosuppression. RMBVP is a tolerable treatment option for R/R PCNSL, with favorable response rates in those with recurrent disease.

Central Nervous System Lymphoma: Novel Therapies

OPINION STATEMENT

Primary central nervous system lymphomas (PCNSLs) are very rare neoplasms and continue to be challenging to treat. While high-dose methotrexate (HD-MTX)-based regimens are the currently accepted standard first-line therapy for newly diagnosed patients, the optimal induction therapies are still unknown. The role of consolidation therapies continues to evolve with a variety of chemotherapy regimens, including high-dose chemotherapy with stem cell rescue and reduced or deferred whole brain radiotherapy being used. Importantly, several recent advances have been made in the treatment of PCNSL. The incorporation of targeted therapy and immune therapy remain promising strategies. Several agents, successfully used in treatment of systemic lymphomas, have shown activity in PCNSL, frequently leading to durable responses in the relapsed/refractory patients. Many ongoing studies will likely lead to a better understanding of the roles of these treatments, especially as the first line and potentially also as maintenance. In addition, the use of molecular profiling to predict disease response to targeted agents and understand relapse patterns will become increasingly important. Clinical trials in PCNSL are critical yet frequently challenging to conduct given the rarity of the condition and lack of suitable subjects. Therefore, multi-institutional and international collaboration is of utmost importance to accelerate progress in understanding the biology and design better treatments for this disease. It is critical to consider patients of all demographics in the design and study of future treatment algorithms to have the largest impact on patient care and outcomes.

Efficacy of Boron Neutron Capture Therapy in Primary Central Nervous System Lymphoma: In Vitro and In Vivo Evaluation

Background: Boron neutron capture therapy (BNCT) is a nuclear reaction-based tumor cell-selective particle irradiation method. High-dose methotrexate and whole-brain radiation therapy (WBRT) are the recommended treatments for primary central nervous system lymphoma (PCNSL). This tumor responds well to initial treatment but relapses even after successful treatment, and the prognosis is poor as there is no safe and effective treatment for relapse. In this study, we aimed to conduct basic research to explore the possibility of using BNCT as a treatment for PCNSL. Methods: The boron concentration in human lymphoma cells was measured. Subsequently, neutron irradiation experiments on lymphoma cells were conducted. A mouse central nervous system (CNS) lymphoma model was created to evaluate the biodistribution of boron after the administration of borono-phenylalanine as a capture agent. In the neutron irradiation study of a mouse PCNSL model, the therapeutic effect of BNCT on PCNSL was evaluated in terms of survival. Results: The boron uptake capability of human lymphoma cells was sufficiently high both in vitro and in vivo. In the neutron irradiation study, the BNCT group showed a higher cell killing effect and prolonged survival compared with the control group. Conclusions: A new therapeutic approach for PCNSL is urgently required, and BNCT may be a promising treatment for PCNSL. The results of this study, including those of neutron irradiation, suggest success in the conduct of future clinical trials to explore the possibility of BNCT as a new treatment option for PCNSL.

Survival prediction based on the gene expression associated with cancer morphology and microenvironment in primary central nervous system lymphoma

Dysregulation of cell morphology and cell-cell interaction results in cancer cell growth, migration, invasion, and metastasis. Besides, a balance between the extracellular matrix (ECM) and matrix metalloprotease (MMP) is required for cancer cell morphology and angiogenesis. Here, we determined gene signatures associated with the morphology and microenvironment of primary central nervous system lymphoma (PCNSL) to enable prognosis prediction. Next-generation sequencing (NGS) on 31 PCNSL samples revealed gene signatures as follows: ACTA2, ACTR10, CAPG, CORO1C, KRT17, and PALLD in cytoskeleton, CDH5, CLSTN1, ITGA10, ITGAX, ITGB7, ITGA8, FAT4, ITGAE, CDH10, ITGAM, ITGB6, and CDH18 in adhesion, COL8A2, FBN1, LAMB3, and LAMA2 in ECM, ADAM22, ADAM28, MMP11, and MMP24 in MMP. Prognosis prediction formulas with the gene expression values and the Cox regression model clearly divided survival curves of the subgroups in each status. Furthermore, collagen genes contributed to gene network formation in glasso, suggesting that the ECM balance controls the PCNSL microenvironment. Finally, the comprehensive balance of morphology and microenvironment enabled prognosis prediction by a combinatorial expression of 8 representative genes, including KRT17, CDH10, CDH18, COL8A2, ADAM22, ADAM28, MMP11, and MMP24. Besides, these genes could also diagnose PCNSL cell types with MTX resistances in vitro. These results would not only facilitate the understanding of biology of PCNSL but also consider targeting pathways for anti-cancer treatment in personalized precision medicine in PCNSL.

Central Nervous System Lymphoma: Approach to Diagnosis and Treatment

Central nervous system lymphoma (CNSL) is a rare form of extranodal non-Hodgkin lymphoma. Central nervous system lymphoma can be primary (isolated to the central nervous space) or secondary in the setting of systemic disease. Treatment of CNSL has improved since the introduction of high-dose methotrexate and aggressive consolidation regimens. However, results after treatment are durable in only half of patients, and long-term survivors may experience late neurotoxicity, impacting quality of life. Given the rarity of this disease, few randomized prospective trials exist. This leaves many questions unanswered regarding optimal first-line and salvage treatments. Recent advances in the knowledge of pathophysiology of CNSL will hopefully help the development of future treatments. This review gives an overview of the epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment of immunocompetent patients with CNSL.

Relapsed Primary Central Nervous System Lymphoma: Current Advances

Primary central nervous system lymphoma is an invasive malignant lymphoma confined to the central nervous system. Although patients undergoing first-line treatment can achieve complete response, most of them still relapse within two years. Relapsed lymphoma is derived from occult lymphoma cells, and B cell receptor pathway activation and immune escape are the key mechanisms for the pathogenesis of PCNSL. Most relapses are in the central nervous system, a small number of relapses are isolated systemic relapses, and clinical symptoms occur early and vary. Current treatments for relapse include high-dose methotrexate rechallenge and other regimens of chemotherapy, whole-brain radiation therapy, hematopoietic stem-cell transplantation, targeted therapy and immunotherapy, which have become promising treatments. The overall prognosis of relapsed PCNSL is very poor, although it is affected by many factors. This article summarizes the mechanisms, related factors, clinical features, follow-up, treatment and prognosis of relapsed primary central nervous system lymphoma.

Recent advances in the management of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal lymphoma primarily involving the brain, spinal cord, or leptomeninges. PCNSL is associated with a relatively poor prognosis compared to other extranodal diffuse large B-cell lymphomas. However, methotrexate-based induction chemotherapy followed by consolidative chemotherapy or high-dose therapy and autologous stem cell transplantation has improved the survival outcome, together with reduced neurotoxicity. Recent studies found that aberrant activation of the B-cell receptor-signaling pathway and activation of the NF-κB are frequent genetic alterations and could be good targets for the treatment of PCNSL. Herein, we have reviewed the current status and recent advances in the biology and management of PCNSL.

GSEA-assisted gene signatures valid for combinations of prognostic markers in PCNSL

Primary central nervous system lymphoma (PCNSL) is a brain malignant non-Hodgkin’s B-cell lymphoma. The standard treatments are high-dose methotrexate (MTX)-based chemotherapies and deferred whole brain radiotherapy. However, MTX resistance-dependent global expression and signaling pathway changes and their relationship with prognoses have not yet been elucidated. Here, we conducted a global expression analysis with next-generation sequencing and gene set enrichment analysis (GSEA) in MTX-resistant PCNSL cell lines (HKBML-MTX and TK-MTX) and PCNSL tissues. In rank scores, genes listed in HKBML-MTX and TK-MTX were enriched in PCNSL with poor prognoses. In fold changes, a part of differentially-expressed genes in PCNSL tissues were also detected in HKBML-MTX and TK-MTX cells; FOXD2-AS1 and MMP19 were commonly expressed in both HKBML-MTX and TK-MTX, FABP5 and CD70 were HKBML-MTX-specifically expressed, and CLCN2, HOXB9, INE1, and LRP5L were TK-MTX-specifically expressed, which may provide a combination of prognostic markers on MTX-sensitivities in PCNSL. Additionally, PCNSL subgroups, divided with hierarchical clustering and Kaplan-Meier methods, included twenty commonly expressed genes in both HKBML-MTX and TK-MTX, ten HKBML-MTX-specifically expressed genes, and two TK-MTX-specifically expressed genes. These results suggest that the GSEA-assisted gene signatures can provide a combination for prognostic markers in recurrent PCNSL with MTX resistances.

Advances and challenges in the treatment of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL), a rare variant of non-Hodgkin's lymphoma, is characterized by distinct biological characteristics and clinical behaviors, and patient prognosis is not satisfactory. The advent of high-dose (HD) methotrexate (HD-MTX) therapy has significantly improved PCNSL prognosis. Currently, HD-MTX-based chemotherapy regimens are recognized as first-line treatment. PCNSL is sensitive to radiotherapy, and whole-brain radiotherapy (WBRT) can consolidate response to chemotherapy; however, WBRT-associated delayed neurotoxicity leads to neurocognitive impairment, especially in elderly patients. Other effective approaches include rituximab, temozolomide, and autologous stem-cell transplantation (ASCT). In addition, new drugs against PCNSL such as those targeting the B-cell receptor signaling pathway, are undergoing clinical trials. However, optimal therapeutic approaches in PCNSL remain undefined. This review provides an overview of advances in surgical approaches, induction chemotherapy, radiotherapy, ASCT, salvage treatments, and novel therapeutic approaches in immunocompetent patients with PCNSL in the past 5 years. Additionally, therapeutic progress in elderly patients and in those with relapsed/refractory PCNSL is also summarized based on the outcomes of recent clinical studies.

Comprehensive approach to diagnosis and treatment of newly diagnosed primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma that affects the brain parenchyma, spinal cord, eyes, and cerebrospinal fluid without evidence of systemic, non-CNS involvement. PCNSL is uncommon and only a few randomized trials have been completed in the first-line setting. Over the past decades, the prognosis of PCNSL has improved, mainly due to the introduction and widespread use of high-dose methotrexate, which is now the backbone of all first-line treatment polychemotherapy regimens. Despite this progress, durable remission is recorded in only 50% of patients, and therapy can be associated with significant late neurotoxicity. Here, we overview the epidemiology, clinical presentation, staging evaluation, prognosis, and current up-to-date treatment of immunocompetent PCNSL patients.

Differential expression of N-linked oligosaccharides in methotrexate-resistant primary central nervous system lymphoma cells

Background

Oligosaccharides of glycoprotein, particularly negatively-charged sialylated N-glycans, on the surface of lymphomas play important roles in cell–cell interactions and bind immunoglobulin-like lectins, causing inflammatory responses and bioregulation. However, their characterizations have largely been unknown in central nervous system (CNS) lymphoma.

Methods

Here, we investigated expression patterns of N-linked oligosaccharides of glycoproteins in cells derived from CNS lymphomas and clinical specimens.

Results

We first generated methotrexate (MTX)-resistant cells derived from HKBML and TK as CNS lymphoma, and RAJI as non-CNS lymphoma and determined N-linked oligosaccharide structures in these cells and other non-CNS lymphoma-derived cells including A4/FUK, OYB, and HBL1. Major components of the total oligosaccharides were high-mannose type N-glycans, whose level increased in MTX-resistant HKBML and TK but decreased in MTX-resistant RAJI. We also detected sialylated biantennary galactosylated N-glycans with α1,6-fucosylation, A2G2F, and A2G2FB from HKBML, TK, and RAJI. Sialylated A4G4F was specifically isolated from RAJI. However, the ratios of these sialylated N-glycans slightly decreased against MTX-resistant compared to non-resistant cells. Interestingly, almost all complex-type oligosaccharides were α2,6-sialylated.

Discussion

This is the first study for the expression profile of N-oligosaccharides on MTX-resistant primary CNS lymphoma-derived cells HKBML and TK, and tumor tissues resected from patients with CNS lymphoma,

Conclusion

These results propose a possibility that the differential expression of high-mannose types and sialylated A2G2F, A2G2FB, and A4G4F on the surface of CNS lymphomas may provide a hint for targets for diagnoses and treatments of the oligosaccharide type-specific lymphomas.

Cell-type-specific sensitivity of bortezomib in the methotrexate-resistant primary central nervous system lymphoma cells

BACKGROUND

Methotrexate (MTX) is used in first-line treatment of primary central nervous system lymphoma (PCNSL), but most cases result in relapse-acquired resistance to MTX. However, only few studies have reported on internal changes and chemotherapies in PCNSL.

METHODS

In this study, we generated two MTX-resistant PCNSL cell lines, designated MTX-HKBML and MTX-TK, in addition to a MTX-resistant Burkitt lymphoma cell line, designated MTX-RAJI. We examined gene expression changes and drug sensitivity to a proteasome inhibitor, bortezomib, in these cells.

RESULTS

Cytotoxic tests revealed that the 50% inhibitory concentration for MTX in MTX-HKBML is markedly higher than that in the other two cell lines. Expression of the genes in MTX and folate metabolisms, including gamma-glutamyl hydrolase and dihydrofolate reductase, are upregulated in both MTX-HKBML and MTX-TK, whereas the gene expression of folylpolyglutamate synthetase, thymidylate synthase, and methylenetetrahydrofolate dehydrogenase 1 were upregulated and downregulated in MTX-HKBML and MTX-TK, respectively, on the other hand, bortezomib sensitivity was observed in MTX-TK, as compared with control TK, but not in MTX-HKBML.

CONCLUSION

These results indicate the cell-type-specific changes downstream of metabolic pathways for MTX and folate, bortezomib sensitivity, and purine and pyrimidine syntheses, in each PCNSL cell line. The MTX-resistant lymphoma cell lines established may be useful for in vitro relapse models for MTX and development of salvage chemotherapy and drug discovery.

Primary Central Nervous System Lymphoma: Molecular Pathogenesis and Advances in Treatment

Primary central nervous system lymphoma (PCNSL) is a group of extranodal non-Hodgkin lymphoma that exhibits specific biological characteristics and clinical behavior, with an aggressive disease course and unsatisfactory patient outcomes. It is of great importance to identify aberrant genetic loci and important molecular pathways that might suggest potential targets for new therapeutics and provide prognostic information. In this review, we listed various genetic and epigenetic alterations that are involved in PCNSL pathogenesis. In the aspect of treatment, we summarized the related literatures and evaluated the efficacy of surgery, induction chemotherapy, radiotherapy, intrathecal chemotherapy, and autologous stem cell transplantation in PCNSL. We also proposed the possible new agents for recurrent and relapse PCNSL based on the result of recent clinical researches.

Management of primary central nervous system lymphoma

A rare tumor, primary central nervous system lymphoma can affect immunocompetent and immunocompromised patients. While sensitive to radiotherapy or chemotherapy crossing the blood-brain barrier, it often recurs. Modern treatment consists of high-dose methotrexate-based induction chemotherapy, often followed by consolidation with either radiotherapy or further chemotherapy. Neurotoxicity is however a concern with radiotherapy, especially for patients older than 60 years. The benefit of the addition of rituximab to chemotherapy is unclear. Targeted therapies and immunotherapy have been effective in some patients and are tested on a larger scale. Survival has improved in the last decade, but remains poor in older patients.

Treatment of Primary Central Nervous System Lymphoma: From Chemotherapy to Small Molecules

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that is typically confined to the brain, eyes, and cerebrospinal fluid (CSF) without evidence of systemic spread. PCNSL is an uncommon tumor, and only four randomized trials and one phase III trial have been completed so far, all in the first-line setting. The prognosis of patients with PCNSL has improved during the past few decades with the introduction of high-dose methotrexate (HD-MTX), which now serves as the backbone of all first-line treatment regimens. Despite recent progress, results after treatment are durable in half of patients, and therapy can be associated with late neurotoxicity. Novel insights into the pathophysiology of PCNSL have identified the B-cell receptor (BCR) pathway as a key mechanism in the pathogenesis of PCNSL. The use of novel agents targeting components of the BCR pathway, namely the Bruton tyrosine kinase (BTK) inhibitor ibrutinib, and immunomodulatory drugs (IMIDs) like lenalidomide and pomalidomide, has so far been limited to patients who have recurrent/refractory PCNSL with promising high response rates. Within the past 5 years, there has been a peak in clinical trials investigating small molecules and novel reagents in the recurrent/refractory setting, including immune checkpoint inhibitors, IMIDs, and BTK and PI3K/AKT/mTOR inhibitors.

Immunochemotherapy using rituximab (RTX) and high-dose methotrexate (HD-MTX): an evaluation of the addition of RTX to HD-MTX in recurrent primary central nervous system lymphoma (PCNSL)

Background

There is increasing evidence that MTX-based chemotherapy is superior to HD-MTX alone. Rituximab (RTX) is effective in a variety of B-cell lymphomas and may enter the brain. The purpose of this study is to evaluate the addition of RTX to HD-MTX in recurrent primary central nervous system lymphoma (PCNSL).

Methods

Patients diagnosed with recurrent PCNSL at our institution between 2004 and 2009 were treated with HD-MTX (3.5-5.5 g/m2) every 2 weeks. From 2010, RTX (375 mg/m2) was administered every 2 weeks along with HD-MTX.

Results

Fifteen recurrences in 10 patients were treated with HD-MTX alone (MTX group). Another 15 recurrences in 10 patients were treated with RTX and HD-MTX (RTX group). In 13 (86.6%) of the 15 recurrences in both groups the pre-planned chemotherapy cycles were completed. In the MTX group, 10/15 (66.6%) recurrences achieved a complete response (CR/CRu), 2/15 (13.3%) recurrences achieved a partial response (PR) and 3/15 (20%) recurrences had progressive disease (PD). In the RTX group, the CR/CRu, PR and PD rates were the same as that in the MTX group. The median time to tumor progression (mTTP) was 9.1 months (range, 1.4-120.9 months) in the MTX group and 7.8 months (range, 0.9-52.3 months) in the RTX group. We found no significant difference in mTTP (9.1 vs. 7.8 months, HR 1.02, 95% CI 0.48-2.18, P = 0.94) between the two groups. All treatment-related toxicities were manageable without any severe events.

Conclusions

The addition of RTX to HD-MTX may not be a promising strategy for recurrent PCNSL. A future study with a larger sample size, longer follow-up, or different RTX dosing/schedule is warranted.

Primary CNS Lymphoma

Primary CNS lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that is typically confined to the brain, eyes, and cerebrospinal fluid without evidence of systemic spread. The prognosis of patients with PCNSL has improved during the last decades with the introduction of high-dose methotrexate. However, despite recent progress, results after treatment are durable in half of patients, and therapy can be associated with late neurotoxicity. PCNSL is an uncommon tumor, and only four randomized trials and one phase III trial have been completed so far, all in the first-line setting. To our knowledge, no randomized trial has been conducted for recurrent/refractory disease, leaving many questions unanswered about optimal first-line and salvage treatments. This review will give an overview of the presentation, evaluation, and treatment of immunocompetent patients with PCNSL.

Ibrutinib in PCNSL: The Curious Cases of Clinical Responses and Aspergillosis

In this issue of Cancer Cell, Lionakis et al. demonstrate that the combination of temozolomide, etoposide, doxorubicin, dexamethasone, rituximab, and the Bruton tyrosine kinase (BTK) inhibitor ibrutinib induced frequent responses in patients with primary central nervous system lymphoma but was associated with significant toxicity, including pulmonary and cerebral aspergillosis infections.

Immunotherapy of Nivolumab with Dendritic Cell Vaccination Is Effective against Intractable Recurrent Primary Central Nervous System Lymphoma: A Case Report

We report effective treatment with nivolumab of a patient with recurrent primary central nervous system lymphoma (PCNSL) after multiple therapies. A 41-year-old woman with a right parietal PCNSL underwent treatment with high-dose methotrexate and radiotherapy. After recurrence in the left frontal lobe, the patient received several chemotherapies, including methotrexate and rituximab, and underwent surgery. The tumor was refractory to these treatments, and the patient then underwent intensity-modulated radiotherapy (IMRT). Multiple small, new recurrent tumors appeared in the right frontal lobe and the left frontoparietal region 2 months after IMRT. The patient received nivolumab 3 mg/kg with dendritic cell vaccination. Complete remission of the tumors was achieved after six cycles of nivolumab, and remission was maintained for 10 months after the initiation of nivolumab. Nivolumab could be a novel treatment for intractable recurrent PCNSL in the future.

Primary CNS lymphoma at first relapse/progression: characteristics, management, and outcome of 256 patients from the French LOC network

BACKGROUND

Treatment of relapsed/refractory (R/R) primary CNS lymphoma (PCNSL) is poorly defined, because randomized trials and large studies are lacking. The aim of this study was to analyze the characteristics, management, and outcome of R/R PCNSL patients after first-line therapy in a nationwide cohort.

METHODS

We analyzed R/R PCNSL patients following first-line treatment who had been prospectively registered in the database of the French network for oculocerebral lymphoma (LOC) between 2011 and 2014.

RESULTS

Among 563 PCNSL patients treated with first-line therapy, we identified 256 with relapsed (n = 93, 16.5%) or refractory (n = 163, 29.0%) disease. Patients who were asymptomatic at relapse/progression (25.5%), mostly diagnosed on routine follow-up neuroimaging, tended to have a better outcome. Patients who received salvage therapy followed by consolidation (mostly intensive chemotherapy plus autologous hematopoietic stem cell transplantation [ICT + AHSCT]) experienced prolonged survival compared with those who did not receive salvage or consolidation therapy. Independent prognostic factors at first relapse/progression were: KPS ≥ 70 vs KPS < 70), sensitivity to first-line therapy (relapsed vs refractory disease), duration of first remission (progression-free survival [PFS] ≥1 y vs <1 y), and management at relapse/progression (palliative care vs salvage therapy). Patients who relapsed early after first-line therapy (ie, PFS < 1 y) had a poor outcome, comparable to that of refractory patients. Conversely, patients experiencing late relapses (PFS ≥ 1 y) and/or undergoing consolidation with ICT + AHSCT experienced prolonged survival.

CONCLUSIONS

About a third of PCNSL patients are primary refractory to first line treatment. We identified several independent prognostic factors that can guide the management of R/R PCNSL patients.

Efficacy of Procarbazine, Lomustine, and Vincristine Chemotherapy for Recurrent Primary Central Nervous System Lymphomas

Background

Optimal treatment for recurrent primary central nervous system lymphomas (PCNSLs) has not been defined yet and there is no general consensus about the salvage chemotherapy after high-dose methotrexate (HD-MTX)-based chemotherapy. The purpose of the present study was to evaluate the efficacy and safety of procarbazine, lomustine, and vincristine (PCV) chemotherapy for recurrent PCNSLs.

Methods

We reviewed eight immunocompetent patients (five males/three females, mean age: 56 years) who received salvage PCV chemotherapy (procarbazine 60 mg/m², days 8 through 21: CCNU 110 mg/m², day 1: vincristine 2 mg, days 8 and 28) for recurrent PCNSL and two patients switched to PCV chemotherapy due to severe adverse effects of HD-MTX chemotherapy. Radiologic responses, survival, and adverse effects were analyzed.

Results

Of the eight recurrent PCNSLs, three patients (37.5%) showed radiologic complete response, one patient (12.5%) showed partial response, and four patients (50%) showed progressive disease after PCV chemotherapy. Median progression free survival (PFS) from the first administration of PCV to relapse or last follow-up was 7 months (range 5-32 months) and median overall survival was 8 months (range 2-41 months). The two patients who switched to PCV chemotherapy showed PFS of 9 and 5 months from the beginning of PCV to relapse. The common side effects were thrombocytopenia, neutropenia, and peripheral neuropathy. There were 4 grade III or IV myelo-suppression, but no fatal complications, including severe hemorrhage or infection, were observed.

Conclusion

Salvage PCV chemotherapy has a moderate anti-lymphoma activity for recurrent PCNSLs after the HD-MTX-based chemotherapy with tolerable toxicity.

Pemetrexed plus rituximab as second-line treatment for primary central nervous system lymphoma

The aim of the study was to determine the efficacy and toxicity of pemetrexed plus rituximab in patients with primary central nervous system lymphoma, who had undergone treatment with high-dose (HD) methotrexate-based regimens. Patients who had failed HD methotrexate-based regimens treatment had ECOG performance status ranging from 0 to 2. Twenty-seven patients received pemetrexed plus rituximab as second-line treatment. Rituximab 375 mg/m(2) was administered on day 0 and pemetrexed 500 mg/m(2) was administered on day 1 every 3 weeks. Six patients (22.2 %) experienced CR, 11 patients (40.7 %) had PR, eight patients (29.6 %) had SD, and two patients had PD. The response rate was 62.9 %. The median time to progression (PFS) was 6.9 months (95 % CI, 5.6-8.3), and the median overall survival was 11.2 months (95 % CI, 9.1-13.4). In the subgroup analysis, PFS had a significant difference among the low level of serum miR-21 and high level of serum miR-21. PFS was 9.0 (95 % CI, 6.3-11.6) and 5.7 months (95 % CI, 4.6-6.9, log rank = 0.015), respectively. None of the patient experienced grade 4 toxicity. A regimen of pemetrexed combined with rituximab is marginally effective and well tolerated in patients with PCNSL who had failed HD methotrexate-based regimens first-line treatment.

18F-FDG PET in the diagnosis and treatment of primary central nervous system lymphoma

This paper summarizes the usefulness and limitation of positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) in the diagnosis and treatment of primary central nervous system lymphoma (PCNSL). The (18)F-FDG uptake in typical PCNSL is about 2.5 times higher than that in the normal gray matter, and the tumor can usually be identified visually. The (18)F-FDG uptake pattern and value provide useful information for differentiating PCNSL from other enhancing malignant brain tumors especially glioblastoma (GB). The (18)F-FDG uptake in typical PCNSL is usually homogenous, and the uptake value is significantly higher than that in GB. However, (18)F-FDG PET often fails to show the presence of tumor in the brain as (18)F-FDG uptake is faint in atypical PCNSL such as disseminated or nonenhancing lesions. (18)F-FDG PET is also useful for evaluating the treatment response at a very early stage after the initial treatment. Pretreatment and posttreatment (18)F-FDG uptake values may have a prognostic value in patients with PCNSL. In conclusion, (18)F-FDG PET is very useful in the diagnosis of typical PCNSL and can differentiate PCNSL from other malignant brain tumors. However, the usefulness of (18)F-FDG PET is limited in the diagnosis of atypical PCNSL.

Primary CNS lymphoma: a clinician's guide

Primary CNS lymphoma is a high malignant disease of the brain which can lead rapidly to death if diagnosis and/or the start of treatment is delayed. The age at time of diagnosis is a strong factor influencing prognosis so that in younger patients <65 years of age long-term survival may be achieved in a substantial percentage of patients, while in elderly patients long-term survival is seen much more rarely. First-line therapy consists of high-dose methotrexate-based (poly)chemotherapy. This review provides an overview of clinical presentation, steps to diagnosis, detailed information about current treatment concepts and specific information for particular clinical situations.

Central nervous system recurrence of systemic lymphoma in the era of stem cell transplantation--an International Primary Central Nervous System Lymphoma Study Group project

Autologous stem cell transplantation has greatly improved the prognosis of systemic recurrent non-Hodgkin's lymphoma. However, no prospective data are available concerning the feasibility and efficacy of this strategy for systemic lymphoma relapsing in the central nervous system. We, therefore, we performed an international multicenter retrospective study of patients with a central nervous system recurrence of systemic lymphoma to assess the outcome of these patients in the era of stem cell transplantation. We collected clinical and treatment data on patients with a first central nervous system recurrence of systemic lymphoma treated between 2000 and 2010 in one of five centers in four countries. Patient- and treatment-related factors were analyzed and compared descriptively. Primary outcome measures were overall survival and percentage of patients transplanted. We identified 92 patients, with a median age of 59 years and a median Eastern Cooperative Oncology Group/World Health Organization performance status of 2, of whom 76% had diffuse large B-cell histology. The majority (79%) of these patients were treated with systemic chemotherapy with or without intravenous rituximab. Twenty-seven patients (29%) were transplanted; age and insufficient response to induction chemotherapy were the main reasons for not being transplanted in the remaining 65 patients. The median overall survival was 7 months (95% confidence interval 2.6-11.4), being 8 months (95% confidence interval 3.8-5.2) for patients ≤ 65 years old. The 1-year survival rate was 34.8%; of the 27 transplanted patients 62% survived more than 1 year. The Memorial Sloan Kettering Prognostic Index for primary central nervous system lymphoma was prognostic for both undergoing transplantation and survival. In conclusion, despite the availability of autologous stem cell transplantation for patients with central nervous system progression or relapse of systemic lymphoma, prognosis is still poor. Long-term survival is, however, possible and more likely in patients able to undergo stem cell transplantation.

Salvage therapy for refractory AIDS-related primary central nervous system lymphoma

A 27-year-old male patient presented with speech disorders and multiple brain masses on MRI evaluation. He tested positive for HIV. A sterotactic biopsy diagnosed primary central nervous system lymphoma (diffuse large B-cell lymphoma). After two cycles of high-dose metotrexate (HD-MTX-)-based chemotherapy, the tumor progressed. He underwent whole brain radiotherapy achieving complete response. Six cycles of consolidating immunochemotherapy with rituximab-temozolomide were administered after radiation. Forty-three months after remission, he has not recurred and his neurological status is optimal. Younger HIV patients with refractory PCNSL and preserved immune function can face salvage therapy successfully achieving long term remissions with no remarkable neurotoxicity.

Salvage treatment with temozolomide in refractory or relapsed primary central nervous system lymphoma and assessment of the MGMT status

High-dose methotrexate (HD-MTX) is effective in the initial treatment of primary central nervous system lymphoma (PCNSL). Because treatment options in patients with progressive or recurrent PCNSL are limited, prognosis is poor. Temozolomide, a well-tolerated oral alkylating agent that permeates the blood brain barrier (BBB), is effective against malignant glioma and recurrent PCNSL. The gene for the deoxyribonucleic acid (DNA) repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT), which is closely related to cellular sensitivity to alkylating agents, is inactivated by promoter hypermethylation. We evaluated the results of temozolomide treatment and the methylation status of the promoter region of the MGMT gene in 17 patients (median age 68 years) with refractory or relapsed PCNSL. They were immunocompetent and had received initial treatment with HD-MTX (3.5 g/m(2)) with or without irradiation. All were treated with temozolomide 150-200 mg/m(2), for 5 days in the course of 28 days; treatment was continued until disease progression. We observed five complete remissions, five partial responses (PRs) with stable disease (SD), and seven with disease progression. Median overall survival after the temozolomide treatment was 6.7 months. One patient manifested grade 3 neutropenia and thrombocytopenia. Eleven tumor specimens were available for MGMT analysis. MGMT promoter methylation (mMGMT) in the tumor tissue was found in 4 (36.4%), the other seven harbored a non-methylated MGMT promoter (nmMGMT). There was no statistically significant difference in median overall survival between patients with mMGMT (11.1 months) and nmMGMT (6.7 months) (P = 0.63). Although some patients were elderly and had been heavily pre-treated, temozolomide resulted in a complete response (CR) in 29% and was well tolerated without any major toxicity.

Late relapse in primary central nervous system lymphoma: clonal persistence

Recurrence of primary central nervous system lymphoma (PCNSL) after initial diagnosis and treatment occurs within 2 years in most patients, and relapse after 5 years is rare. We evaluated late relapse in our PCNSL population. We identified 10 patients from our database of 378 patients (268 achieved a complete response and 230 had relapse) with PCNSL who had relapse ≥5 years after initial diagnosis. At initial diagnosis, their median age was 47 years; all patients had brain involvement and achieved a complete response to initial therapy (9 received high-dose methotrexate). Median time to first relapse was 7.4 years (range, 5.2-14.6 y). Eight patients had relapse in the brain, 1 had ocular relapse, and 1 had a systemic relapse. The histologic specimens at initial diagnosis and relapse were examined for clonal rearrangement in 3 patients; 1 had the identical clone at initial diagnosis and relapse 13.8 years later, and the other 2 were uninformative. All patients received salvage therapy (9 received systemic therapy and 1 received intraocular chemotherapy. Nine patients achieved a complete response to salvage therapy and 1 achieved a partial response. Four patients had relapse a second time. The median progression-free survival after first relapse was 31 months (range, 7.9-82.4). Late relapses accounted for 4% of all recurrences (10 of 230 patients) in our PCNSL population. Long-term persistence of the PCNSL clone was observed in one patient. Patients with late relapses have a good response to salvage therapy and prolonged survival.

Management of immunocompetent patients with primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma (PCNSL) is a non-Hodgkin lymphoma that arises within and is confined to the CNS. Recent data have suggested an increasing incidence in immunocompetent individuals, with a peak of incidence between 60 and 70 years of age. Patients with PCNSL present mostly with symptoms of increased intracranial pressure. The clinical management of these patients remains controversial, and the optimal treatment for patients with PCNSL has not yet been defined. Surgery, even if macroscopically radical, does not improve survival because of the multifocal and infiltrative nature of PCNSL; furthermore, the deep location of most of these tumors makes patients susceptible to serious and irreversible neurologic sequelae. Corticosteroids have a specific role in the treatment of patients with PCNSL, whose disease is sensitive to them as a chemotherapeutic agent. PCNSL is an extremely radiation-sensitive neoplasm; whole-brain radiation therapy plus corticosteroids was the first modality of treatment for patients with this neoplasm until 10 years ago, with a low cure rate and a high local recurrence rate. PCNSL is also a chemosensitive neoplasm; while the optimal choice, sequence, and combination of appropriate agents for efficacious treatment of patients with PCNSL has yet to be determined. An essential component of therapy must include an adequate drug delivery behind a normal blood-brain barrier. Methotrexate is the agent with the most proven activity in PCNSL. Combined-modality therapy has improved survival, but relapse is still common, and late neurologic toxicity is a significant complication, especially in older patients, who represent the majority of immunocompetent patients with PCNSL.

Salvage therapy and late neurotoxicity in patients with recurrent primary CNS lymphoma treated with a modified ProMACE-MOPP hybrid regimen

We report the efficacy of salvage therapy with a modified ProMACE-MOPP combined with radiation in patients with primary central nervous system lymphoma (PCNSL). Thirty-two immunocompetent patients were treated with a regimen of pirarubicin, cyclophosphamide, etoposide, vincristin, and methotrexate (MTX: 500 mg/m(2)) administered in 21-day cycles. Patients received 20 Gy of whole-brain radiotherapy after three cycles of chemotherapy. A single cycle of chemotherapy was repeated every four months for two years. Nine patients with CNS relapse were retreated with additional cycles of the ProMACE-MOPP hybrid regimen with a 90% objective response rate. Median complete response (CR) duration was 13.2 months and median survival time (MST) for the nine patients treated after initial relapse was 30 months. One of 17 patients (5.8%) who had less than 20 Gy of whole brain irradiation developed dementia. In contrast, six of seven (85.7%) patients who had more than 30 Gy of whole brain radiotherapy became demented. Maintaining a moderate dose of MTX, while adding chemotherapeutic agents and 20 Gy of whole brain radiation therapy, improved disease control and overall survival and lowered the incidence of delayed neurologic toxicity in patients with PCNSL. Additional treatment with a ProMACE-MOPP hybrid regimen is still effective for relapsed disease.

A successful treatment of relapsed primary CNS lymphoma patient with intraventricular rituximab followed by high-dose chemotherapy with autologous stem cell rescue

The prognosis for patients with primary central nervous system (CNS) lymphoma (PCNSL) who relapse after the initial response is usually poor. A standard treatment for relapsed PCNSL has not yet been identified because of the heterogeneity of the therapies employed and the lack of large, prospective clinical trials. We describe a 46-year-old relapsed PCNSL patient who was successfully treated with intraventricular applications of rituximab to minimize neurotoxicity, 2 cycles of salvage chemotherapy with etoposide, ifosfamide, and cytarabine (VIA) regimen and high-dose chemotherapy with autologous stem cell rescue. The high-dose chemotherapy consisted of bischloroethylnitrosourea, etoposide, cytarabine, and melphalan (BEAM) regimen. Partial remission was detected after intraventricular rituximab therapy and the patient has been in complete remission without evidence of neurotoxicity for 28 months after high-dose chemotherapy with autologous stem cell rescue. This case indicates a new appropriate treatment guideline in relapsed PCNSL patient after initial intensive chemo-radiotherapy.

Study of radiolabeled indium-111 and yttrium-90 ibritumomab tiuxetan in primary central nervous system lymphoma

BACKGROUND

Therapeutic options for refractory or recurrent primary central nervous system lymphoma (PCNSL) are limited. The blood-brain barrier makes many agents used in systemic lymphomas ineffective in CNS lymphomas. The objective of this study was to determine whether intravenous radioimmunotherapy using anti-CD20 antibody can be delivered to PCNSL.

METHODS

This was a single-institution prospective study. Indium-111 ibritumomab tiuxetan was used for imaging and dosimetry. Yttrium-90 ibritumomab tiuxetan at doses of 0.3 to 0.4 mCi/kg were subsequently given for the treatment of recurrent or refractory PCNSL. 111In data were used to estimate radiation doses to lesions delivered by 90Y ibritumomab tiuxetan therapy.

RESULTS

Six patients (4 men, 2 women) with a median age of 60 years and median Karnofsky performance status of 70 received both indium-111 and yttrium-90 ibritumomab tiuxetan. The median absorbed dose delivered to the CNS lymphoma was 701 cGy compared with 70 cGy to normal brain. The median progression-free and overall survival times were 6.8 weeks and 14.3 weeks, respectively.

CONCLUSIONS

The results from this study suggest that it may be feasible to deliver radiolabeled monoclonal anti-CD20 antibodies as a component of therapy for PCNSL.

Primary central nervous system lymphomas: salvage treatment after failure to high-dose methotrexate

This review analyzes the major methodological caveats related to the design and conduction of trials addressing new active drugs in patients with failed primary CNS lymphoma (PCNSL) and provides some recommendations for their therapeutic management. The enrollment of patients in well-designed prospective trials is the best option at failure. In the clinical practice, radiotherapy is an option for unirradiated patients and re-treatment with high-dose methotrexate (HD-MTX) can be suggested to relapsing patients who experienced a prolonged lymphoma remission after first-line chemotherapy containing HD-MTX. Salvage monochemotherapy with temozolomide or topotecan in patients previously managed with a radiotherapy-containing approach is supported by prospective trials, while the combination chemotherapy remains investigational. High-dose chemotherapy supported by stem cell autotransplant and intrathecal chemotherapy in meningeal failure have to be further investigated in prospective trials.

Complete response to temozolomide treatment in an elderly patient with recurrent primary central nervous system lymphoma--case report

An 80-year-old woman presented with primary central nervous system (CNS) lymphoma manifesting as progressive disorientation and loss of activity. She received three cycles of high-dose methotrexate. The tumor shrank after two cycles and her mental status improved, but she suffered tumor recurrence. The second-line treatment consisted of four cycles of rituximab but the tumor enlarged. She was then treated with three cycles of temozolomide. Magnetic resonance imaging revealed no evidence of disease. Her mental status and performance status improved, and she suffered no toxicity. She is able to pursue her daily life without recurrence after 16 cycles of temozolomide. Temozolomide may be effective against relapsed primary CNS lymphoma without causing neurotoxicity in the elderly.

Primary central nervous system lymphoma

Primary central nervous system lymphomas (PCNSL) are aggressive malignancies that arise in distinct anatomical sites, which display unique structural, biological and immunological conditions. So far, despite recent therapeutic advances, these malignancies exhibit one of the worst prognoses among all non-Hodgkin lymphomas (NHL). For a long time, radiotherapy (RT) has been the standard treatment, producing a response rate of 60-65% and a notable neurological improvement in most cases. However, relapse usually occurred within a few months after RT, with a median survival of 14 months and a 5-year survival of approximately 15-24%. Although the introduction of systemic chemotherapy has consistently improved survival, the prognosis of PCNSL is still dismal, with high rates of local relapse and consequent death. Defining the optimum therapeutic management is difficult because of potential selection biases in large retrospective reviews and the limited number of prospective studies. Although studies published on PCNSL are increasing, several therapeutic questions still remain unanswered after a decade of research.

Temozolomide as salvage treatment in primary brain lymphomas

Methotrexate (MTX)-based chemotherapy extends survival in patients with primary brain lymphomas, but it is not clear whether multiagent chemotherapy is superior to MTX alone. Treatment options for patients with recurrent primary brain lymphoma are limited; there is no standard second-line chemotherapy. New chemotherapeutic agents with clear activity in brain lymphoma are needed for treatment of recurrent disease. We report the results of a phase II trial assessing activity of the alkylating agent temozolomide in immunocompetent patients with recurrent primary brain lymphomas, previously treated with high-dose MTX-containing chemotherapy and/or radiotherapy. A median of two courses (range 1–12) of temozolomide 150 mg m⁻² day⁻¹, for 5 days every 4 weeks was administered to 36 patients yielding nine complete and two partial responses (response rate: 31%; 95% confidence interval 16–46%). One-year survival was 31% (95% confidence interval 16–46%). Toxicity was negligible. We conclude that temozolomide is active in recurrent primary brain lymphomas and should further be evaluated in this disease, perhaps in combination with MTX as initial treatment.

An Update on Primary Central Nervous System Lymphoma

The most important recent advance in treatment of primary central nervous system lymphoma has been the introduction of high-dose methotrexate-based chemotherapy. Convincing data demonstrate that the regimens of such chemotherapy improve survival compared with historical controls treated with radiotherapy alone. However, the optical treatment approach is still unclear and therapy can be associated with long-term neurotoxicity. Current research focuses on maximizing survival while minimizing neurologic sequelae.