High-dose methotrexate and rituximab with deferred radiotherapy for newly diagnosed primary B-cell CNS lymphoma

First-line induction chemotherapy with high-dose methotrexate versus teniposide in patients with newly diagnosed primary central nervous system lymphoma: a retrospective, multicenter cohort study

BACKGROUND

This study aimed to compare the efficacy and safety of high-dose methotrexate (HD-MTX) versus teniposide (TEN) in patients with newly diagnosed immunocompetent primary central nervous system lymphomas (PCNSLs).

METHODS

The study included immunocompetent, adult patients with newly diagnosed PCNSL at 22 centers in China from 2007 to 2016. The patients received HD-MTX or TEN as first-line induction therapy. The objective response rate, progression-free survival, and overall survival were analyzed for each patient cohort.

RESULTS

A total of 96 patients were eligible: 62 received HD-MTX, while 34 received teniposide. The overall response rate was 73.2% and 72.7% in the MTX and the TEN cohorts, respectively (P = 0.627). The median progression-free survival was 28.4 months [95% confidence interval (CI): 13.7-51.2] in the MTX cohort and 24.3 months (95% CI: 16.6-32.1) in the TEN cohort (P = 0.75). The median overall survival was 31 months (95% CI: 26.8-35.2) in the MTX cohort and 32 months (95% CI: 27.6-36.4) in the TEN cohort (P = 0.77). The incidence of any grade of coagulopathy/deep-vein thrombosis and gastrointestinal disorders was significantly higher in the MTX cohort than in the TEN cohort; no significant difference was found in the incidence of other adverse events between the two cohorts.

CONCLUSIONS

This was the first multicenter study using TEN as the main agent compared with HD-MTX in newly diagnosed primary CNS lymphoma. The TEN-based regimen was non-inferior to the HD-MTX-based regimen with similar overall responses.

CLASSIFICATION OF EVIDENCE

This study provided Class III evidence that the teniposide-based regimen was non-inferior to high-dose methotrexate - based regimen with similar overall responses and long-time survival in immunocompetent patients with PCNSL.

Genomic Profiling Reveals Differences in Primary Central Nervous System Lymphoma and Large B-Cell Lymphoma, With Subtyping Suggesting Sensitivity to BTK Inhibition

BACKGROUND

B-cell primary central nervous system (CNS) lymphoma (PCL) is diffuse large B-cell lymphoma (DLBCL) confined to the CNS. Less than 50% of patients with PCL achieve complete remission with current therapies. We describe the findings from comprehensive genomic profiling (CGP) of a cohort of 69 patients with PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL to highlight their differences and characterize the PCL cohort. In addition, we highlight the differences in frequency of germinal center B-cell like (GCB) and non-GCB subtypes and molecular subtypes, particularly MCD and EZH subtypes, between PCL and DLBCL.

MATERIALS AND METHODS

Sixty-nine cases of B-cell PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL were evaluated by CGP of 405 genes via DNAseq and 265 genes via RNAseq for fusions (FoundationOne Heme). Tumor mutational burden (TMB) was calculated from 1.23 Mb of sequenced DNA.

RESULTS

Genomic alterations with significant differences between PCL and DLBCL included MYD88, ETV6, PIM1, PRDM1, CXCR4, TP53, and CREBBP, while only MYD88 was significantly different between SCL and DLBCL. PCL cases were significantly enriched for the MCD molecular subtypes, which have an excellent response to BTKi. We report a patient with a durable complete response to BTKi consistent with their genomic profile. EBV status, CD274 amplification, and TMB status suggest that 38% of PCL patients may benefit from ICPI; however further study is warranted.

CONCLUSION

CGP of PCLs reveals biomarkers, genomic alterations, and molecular classifications predictive of BTKi efficacy and potential ICPI efficacy. Given the limitations of standard of care for PCL, CGP is critical to identify potential therapeutic approaches for patients in this rare form of lymphoma.

Resection versus biopsy for management of primary central nervous system lymphoma: a meta-analysis

The role of surgery in the management of primary central nervous system lymphomas (PCNSL) is currently confined to diagnosis. However, over recent years, an increasing number of papers have suggested a possible positive prognostic impact of surgery in selected cases. The present work aims to perform a meta-analysis of the available literature evidence. A meta-analysis with meta-regression on the role of surgical resection compared to biopsy in the management of PCNSL was conducted according to the PRISMA statement, searching MEDLINE via PubMed and Embase. The random effect model was used. The quality of evidence was assessed using the GRADE framework. After screening 1395 records, we included 11 papers in our analysis. Patients who underwent surgical resection harbored superficial and single-lesion tumors. At 1-, 2-, and 5-year follow-up, progression-free survival did not differ between the two groups, while overall survival favored resection, even if in a non-significant fashion. Meta-regression analysis showed that the overall survival rate at 2 years, but not at 1 or 5 years, was significantly influenced by tumor location. There were no differences in terms of age, sex, Karnofsky performance status, adjuvant therapy, or procedure-related complications. Overall, the quality of evidence is low. The results of the present meta-analysis do not change the current standard of care for PCNSL. However, surgery could be non-inferior to biopsy with an acceptable risk profile in selected patients harboring single and superficial lesions. The low quality of evidence prompts future randomized studies.

European Association of Neuro-Oncology (EANO) guidelines for treatment of primary central nervous system lymphoma (PCNSL)

The management of primary central nervous system (PCNSL) is one of the most controversial topics in neuro-oncology because of the complexity of the disease and the limited number of controlled studies available. In 2021, given recent advances and the publication of practice-changing randomized trials, the European Association of Neuro-Oncology (EANO) created a multidisciplinary task force to update the previously published evidence-based guidelines for immunocompetent adult patients with PCNSL and added a section on immunosuppressed patients. The guideline provides consensus considerations and recommendations for the treatment of PCNSL, including intraocular manifestations and specific management of the elderly. The main changes from the previous guideline include strengthened evidence for the consolidation with ASCT in first-line treatment, prospectively assessed chemotherapy combinations for both young and elderly patients, clarification of the role of rituximab even though the data remain inconclusive, of the role of new agents, and the incorporation of immunosuppressed patients and primary ocular lymphoma. The guideline should aid the clinicians in everyday practice and decision making and serve as a basis for future research in the field.

Cerebrospinal fluid soluble programmed death‐ligand 1 is a useful prognostic biomarker in primary central nervous system lymphoma

The increased expression of programmed death-ligands 1 and 2 (PD-L1 and PD-L2, respectively) on tumour cells contributes to immune evasion, suggesting that these proteins are attractive therapeutic targets. This study aimed to evaluate the validity of cerebrospinal fluid (CSF) soluble PD-L1 (sPD-L1) and soluble PD-L2 (sPD-L2) as biomarkers for primary central nervous system lymphoma (PCNSL). We determined the CSF concentrations of sPD-L1 and sPD-L2 in 46 patients with PCNSL using enzyme-linked immunosorbent assays (ELISAs). A control group comprised 153 patients with other brain tumours, inflammatory/infectious status, or neurodegenerative diseases. Only CSF sPD-L1 levels were significantly higher in patients with PCNSL relative to the controls. CSF sPD-L1 also exhibited superior overall discrimination performance compared to CSF sPD-L2 in diagnosing PCNSL. Compared with patients with PCNSL with low CSF sPD-L1 levels, more patients with high levels had high serum lactate dehydrogenase levels, leptomeningeal involvement, and deep-brain involvement. Furthermore, CSF sPD-L1 could predict poor survival in PCNSL but CSF sPD-L2 could not. Intriguingly, CSF sPD-L1 levels were correlated with disease status and their dynamic changes post treatment could predict time to relapse. In conclusion, this study identified CSF sPD-L1 as a promising prognostic biomarker, indicating a therapeutic potential of PD-L1 blockade in PCNSL.

Surgical resection versus biopsy in the treatment of primary central nervous system lymphoma: a systematic review and meta-analysis

PURPOSE

Despite the improvement in treatment and prognosis of primary central nervous system lymphoma (PCNSL) over the last decades, the 5-year survival rate is approximately 30%; thus, new therapeutic approaches are needed to improve patient survival. The study's aim was to evaluate the role of surgical resection of PCNSL.

METHODS

Primary outcomes were the overall survival (OS) and progression-free survival (PFS) of patients with PCNSL who underwent surgical resection versus biopsy alone. The meta-analysis was conducted to calculate pooled hazard ratios (HRs) under a random-effects model for the time-to-event variables. The odds ratios (ORs) were calculated for binary, secondary outcome parameters.

RESULTS

Seven studies (n = 1046) were included. We found that surgical resection was associated with significantly better OS (HR 0.63 [95% CI 0.51-0.77]) when compared with biopsy. PFS was also significantly improved (HR 0.64 [95% CI 0.49-0.85]) in patients who underwent resection compared with those who underwent biopsy. The heterogeneity for OS and PFS was low (I2 = 7% and 24%, respectively). We also found that patients who underwent biopsy more often had multiple (OR 0.38 [95% CI 0.19-0.79]) or deep-seated (OR 0.20 [95% CI 0.12-0.34]) lesions compared with those who underwent surgical resection. There were no significant differences in chemotherapy or radiotherapy use or the occurrence of postoperative complications between the two groups.

CONCLUSION

In selected patients, surgical resection of PCNSL is associated with significantly better overall survival and progression-free survival compared with biopsy alone.

High-dose methotrexate dosing strategy in primary central nervous system lymphoma

The backbone induction therapy for primary central nervous system lymphoma (PCNSL) is high dose methotrexate (HD-MTX) and rituximab, which can be combined with other chemotherapeutic agents. The optimal dose of HD-MTX remains unclear, as doses between 3 and 8 g/m² have been shown to be effective. In this retrospective study, HD-MTX dosed at 3-5 g/m² demonstrated an overall response of 81.8%, with 11 (50%) complete responses. The median overall survival was not met at 29 months and median progression free survival was 12.5 months.There were two discontinuations due to nephrotoxicity. The most common adverse event was hepatotoxicity (18.5%), with no treatment-related mortality events observed.Overall, HD-MTX dosed at 3-5 g/m² demonstrated similar efficacy and lower toxicity compared to higher doses in PCNSL patients. Reducing the initial HD-MTX dose may help ensure tolerability and completion of induction therapy, especially in patients with co-morbidities or older age who have poorer outcomes.

Continued-Maintenance Therapy with High-dose Methotrexate Improves Overall Survival of Patients with Primary Central Nervous System Lymphoma

BACKGROUND

PCNSL is mainly treated with HD-MTX-based chemotherapy with or without WBRT. However, As WBRT is associated with delayed neurotoxicity leading to dementia in the elderly, many institutes reported benefits of intensive chemotherapy or high-dose chemotherapy with ASCT. We investigated whether treatment with HD-MTX and rituximab, followed by continued-maintenance HD-MTX monotherapy (3.5g / m2), improves overall survival (OS).

METHODS

In this retrospective, single-center trial 52 immunocompetent patients with newly diagnosed PCNSL were included. All were treated between January 2005 and December 2017. The controls were 18 patients who, between 2005 and 2011, had received 3 cycles of HD-MTX and then adjuvant treatment with WBRT. In 2011 we started HD-MTX continued-maintenance therapy to treat 34 PCNSL patients. In the induction phase, these patients received HD-MTX every 14 days until a complete response (CR) was observed. When CR was obtained, maintenance therapy with HD-MTX (3.5g / m2) was delivered every three months.

RESULTS

In 3-year overall survival (OS) there was a statistically significant difference between the two groups [controls : 33.1% (95%, CI 12.4 - 55.7%) ; maintenance group : 74.9% (95%, CI 55.6 - 86.7%) (p < 0.02)]. Conclusion : The induction of HD-MTX based chemotherapy followed by continued-maintenance HD-MTX monotherapy improved OS compared with chemoradiotherapy consisting of HD-MTX followed by WBRT. J. Med. Invest. 68 : 286-291, August, 2021.

Update on Novel Therapeutics for Primary CNS Lymphoma

Simple Summary

Primary central nervous system lymphoma is a rare and aggressive form of non-Hodgkin lymphoma. While it is highly responsive to first-line chemo and radiation treatments, rates of relapse are high, demonstrating the need for improved therapeutic strategies. Recent advancements in the understanding of the pathophysiology of this disease have led to the identification of new potential treatment targets and the development of novel agents. This review aims to discuss different targeted strategies and review some of the data supporting these approaches, and discusses recently completed and ongoing clinical trials using these novel agents.

Abstract

Primary central nervous system lymphoma (PCNSL) is a rare lymphoma isolated to the central nervous system or vitreoretinal space. Standard treatment consists of cytotoxic methotrexate-based chemotherapy, with or without radiation. Despite high rates of response, relapse is common, highlighting the need for novel therapeutic approaches. Recent advances in the understanding of PCNSL have elucidated mechanisms of pathogenesis and resistance including activation of the B-cell receptor and mammalian target of rapamycin pathways. Novel treatment strategies such as the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, phosphatidylinositol-3 kinase (PI3K) inhibitors, and immunomodulatory drugs are promising. Increasingly, evidence suggests immune evasion plays a role in PCNSL pathogenesis and several immunotherapeutic strategies including checkpoint inhibition and targeted chimeric antigen receptor T (CAR-T) cells are under investigation. This review provides a discussion on the challenges in development of targeted therapeutic strategies, an update on recent treatment advances, and offers a look toward ongoing clinical studies.

Current and emerging therapies for primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma (PCNSL) is a rare type of extranodal lymphoma exclusively involving the CNS at the onset, with diffuse large B-cell lymphoma (DLBCL) as the most common histological subtype. As PCNSL is a malignancy arising in an immune-privileged site, suboptimal delivery of systemic agents into tumor tissues results in poorer outcomes in PCNSL than in non-CNS DLBCLs. Commonly used regimens for PCNSL include high-dose methotrexate-based chemotherapy with rituximab for induction therapy and intensive chemotherapy followed by autologous hematopoietic stem cell transplantation or whole-brain radiotherapy for consolidation therapy. Targeted agents against the B-cell receptor signaling pathway, microenvironment immunomodulation and blood-brain barrier (BBB) permeabilization appear to be promising in treating refractory/relapsed patients. Chimeric antigen receptor-T cells (CAR-T cells) have been shown to penetrate the BBB as a potential tool to manipulate this disease entity while controlling CAR-T cell-related encephalopathy syndrome. Future approaches may stratify patients according to age, performance status, molecular biomarkers and cellular bioinformation. This review summarizes the current therapies and emerging agents in clinical development for PCNSL treatment.

Primary central nervous system lymphoma: a narrative review of ongoing clinical trials and goals for future studies

Primary central nervous system lymphoma (PCNSL) is a rare disease of the brain, spine, cerebrospinal fluid (CSF) and/or vitreoretinal space. PCNSL is chemo and radiosensitive but relapse is common even years after initial treatment. Outside of consensus regarding the use of high-dose methotrexate (HD-MTX) for first line treatment, there is little uniformity in the management of newly diagnosed or relapsed PCNSL. The lack of consensus is driven by a paucity of randomized trials in this disease. Prospective studies are troubled by low enrollment, the lack of a standard induction regimen, and a varied approach to consolidation strategies. Moreover, the PCNSL patient population is heterogeneous and includes a high proportion of elderly or frail patients and consists of patients manifesting disease in varied compartments of the central nervous system (CNS). As a result, current treatment strategies vary widely and are often dictated by physician and institutional preference or regional practice. This review provides an overview of recently completed and ongoing therapeutic studies for patients with newly diagnosed and recurrent or refractory PCNSL. It discusses the existing evidence behind common approaches to induction and consolidation or maintenance regimens as well as the recent data regarding management of recurrent disease. Finally, it highlights the complexity of trial design in this disease and provides a framework for the design of future studies, which are needed to identify patient populations likely to benefit from specific induction, consolidation, or maintenance therapies.

A single-center retrospective analysis of outcome measures and consolidation strategies for relapsed and refractory primary CNS lymphoma

BACKGROUND

Relapsed or refractory primary CNS lymphoma (rrPCNSL) is a rare and challenging malignancy for which better evidence is needed to guide management.

METHODS

We present a retrospective cohort of 66 consecutive patients with rrPCNSL treated at the University of Washington between 2000 and 2020. Immunosuppressed and secondary CNS lymphoma patients were excluded.

RESULTS

During a median follow-up of 40.5 months from initial diagnosis, median OS for relapsed disease was 14.1 (0.2-88.5) months and median PFS was 11.0 (0.2-73.9) months. At diagnosis (r² = 0.85, p < 0.001), first relapse (r² = 0.69, p < 0.001), multiple relapses (r² = 0.97, p < 0.001) PFS was highly correlated with OS. In contrast, there was no correlation between the duration of subsequent progression-free intervals. No difference in PFS or OS was seen between CSF or intraocular relapse and parenchymal relapse. Patients reinduced with high-dose methotrexate-based (HD-MTX) regimens had an overall response rate (ORR) of 86.7%. Consolidation with autologous stem cell transplant (ASCT) was associated with longer PFS compared to either no consolidation (p = 0.01) and trended to longer PFS when compared to other consolidation strategies (p = 0.06). OS was similarly improved in patients consolidated with ASCT compared with no consolidation (p = 0.04), but not compared with other consolidation (p = 0.22). Although patients receiving ASCT were younger, KPS, sex, and number of recurrences were similar between consolidation groups. A multivariate analysis confirmed an independent effect of consolidation group on PFS (p = 0.01), but not OS.

CONCLUSIONS

PFS may be a useful surrogate endpoint which predicts OS in PCNSL. Consolidation with ASCT was associated with improved PFS in rrPCNSL.

Chemoradiotherapy with temozolomide after high-dose methotrexate for primary CNS lymphoma: a multicenter phase I study of a response-adapted strategy

This study aimed to define the maximum tolerated dose (MTD) of temozolomide (TMZ) concurrent with radiotherapy (RT) after high-dose methotrexate (HD-MTX) for newly diagnosed primary central nervous system lymphoma (PCNSL). Adult patients with PCNSL were treated according to a response-adapted strategy. HD-MTX (3.5 g/m²) was followed by concomitant RT and escalating TMZ (50-60-75 mg/m²/day, 5 days/week). The total radiation dose was modulated according to the patient's response to HD-MTX. All patients received 30 Gy to the whole brain plus leptomeninges to C2, including the third posterior of the orbital cavity (clinical target volume 2; CTV2), plus 6, 10, or 16 Gy to the primary site, including the residual mass (CTV1), if a complete response (CR), partial response (PR)/stable disease (SD), or progressive disease (PD) was observed, respectively. Acute toxicities were graded according to the RTOG-EORTC criteria. Dose-limiting toxicity (DLT) was defined as grade 4 hematological toxicity or grade 3-4 hepatic toxicity, although 75 mg/m²/day was the maximum dose regardless of DLT. Neurocognitive function was evaluated using the Mini-Mental State Examination. Three patients were enrolled at each TMZ dose level (total = 9 patients). Twelve lesions were treated. Six patients received 2 cycles of HD-MTX, while 3 received only 1 cycle because of hepatic or renal toxicity. All patients completed chemoradiotherapy without interruptions. No DLT events were recorded. TMZ appears to be tolerable at a dose of 75 mg/m²/day when administered concomitantly with radiotherapy and after HD-MTX.

The Role of Rituximab in Primary Central Nervous System Lymphoma

Purpose of Review

The treatment of primary central nervous system lymphoma (PCNSL) is still under debate. One of the issues is the role of rituximab in improving the outcome. Here, we summarize the existing evidence, and comment on the literature on this topic.

Recent Findings

Two randomized controlled studies have been published recently, with conflicting results. Although the evidence of the benefit of rituximab is limited, it is already incorporated into many treatment regimens, both in studies and in standard clinical practice.

Summary

The use of rituximab in PCNSL is still a matter of debate. A positive effect on the outcome is uncertain. However, there are no clinical signs of significantly increased toxicity. The uncertain positive effect should therefore be weighed against the increased costs of the treatment.

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.

Rapid infusion rituximab is well tolerated in patients with primary CNS lymphoma

Aim:

To establish the safety and feasibility of rapidly infusing rituximab over 90 min in patients with primary CNS lymphoma (PCNSL).

Patients & methods:

We retrospectively reviewed all patients with PCNSL who received rapid rituximab infusions (RRI) from January 2016 to January 2017. Primary end point was incidence of infusion reactions.

Results & conclusion:

11 patients received a total of 44 RRIs. Rituximab was dosed at 500 or 750 mg/m². Premedication included acetaminophen and diphenhydramine. No infusion reactions occurred during any RRI. Two infusions were administered with steroids for neurologic symptoms at baseline (4.5%). Rapid administration of rituximab was safe and feasible for patients with PCNSL and at the higher doses received.

Improving outcomes in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive disease with previously poor prognosis. The advent of high-dose methotrexate-based induction regimens as well as use of consolidation therapy has greatly improved this prognosis in recent decades, but durable remission still eludes half of patients. In this review, we summarize the progress made in the treatment of PCNSL as well as the challenges that remain, with a focus on defining optimal induction and consolidation regimens, including the promise of developing biotherapies. Future studies will help delineate the best combination of existing and novel treatment strategies, with the goal of expanding the cohort of patients achieving a cure.

Impact of front line relative dose intensity for methotrexate and comorbidities in immunocompetent elderly patients with primary central nervous system lymphoma

Primary central nervous system lymphomas (PCNSL) are non-Hodgkin lymphomas strictly localized to the CNS, occurring mainly in elderly patients with comorbidities. Current treatment in fit patients relies on high-dose methotrexate and high-dose cytarabine. The aim of this study was to evaluate the efficacy and feasibility of this treatment in elderly patients and to assess potential prognostic factors associated with survival. We conducted a retrospective study in two centers between January 2008 and September 2015 including 35 elderly immunocompetent patients who received first-line treatment with high-dose methotrexate. With a median follow-up of 19.8 months (range: 1.7-73.4 months), median overall survival (OS) was 39.5 months (95% confidence interval (95% CI): 18.3-60.7) and median progression-free survival (PFS) was 25.8 months (95% CI: 5.2-46.4). In univariate analysis, administration of high-dose cytarabine and achieving a relative dose intensity for methotrexate > 75% were associated with increased OS (p = 0.006 and p = 0.003, respectively) and PFS (p = 0.003 and p = 0.04, respectively) whereas comorbidities, defined by a CIRS-G score ≥ 8, were associated with decreased OS and PFS (p = 0.02 and p = 0.04, respectively). A high MSKCC score was associated with decreased OS (p = 0.02). In multivariate analysis, administration of high-dose cytarabine was associated with increased OS and PFS (p = 0.02 and p = 0.007, respectively). Comorbidities and relative dose intensity for methotrexate are important for the prognosis of elderly patients with PCNSL. These results must be confirmed in prospective trials.

Response-adapted radiation therapy for newly diagnosed primary diffuse large B-cell lymphoma of the CNS treated with methotrexate-based systemic therapy

Background

For patients with primary diffuse large B-cell lymphoma of the central nervous system (PCNSL), whole-brain radiation therapy (WBRT) to doses of ≥45 Gy are often given after a partial response (PR) to methotrexate-based induction chemotherapy. We conducted an exploratory analysis to determine whether lower-dose WBRT, given with a boost to sites of persistent disease, might be a reasonable alternative.

Methods and materials

We retrospectively reviewed the records of 22 patients with PCNSL who received WBRT, with or without a boost, after methotrexate-based induction chemotherapy. Outcomes were compared among patients according to response to chemotherapy using the Kaplan-Meier method.

Results

Median follow-up was 52 months. All patients with a complete response (CR) (n = 5) received WBRT to 23.4 Gy. One CR patient died after an in-field relapse. Patients with partial response (PR) (n = 10) received a median whole-brain dose of 23.4 Gy with (n = 8) or without (n = 2) a boost; there were 2 relapses within the central nervous system (CNS). All PR patients were alive at the time of analysis. The overall survival (P = .127) and freedom from relapse within the CNS (P = .967) were not different for patients with CR versus PR. Baseline and follow-up neurocognitive evaluations were available for 4 PR patients, and there were no significant differences between pre- and post-treatment evaluations (P > .05 for language, memory, visual-spatial, attention, or motor functions). All patients who progressed or did not respond to chemotherapy and then received WBRT had died at a median time of 3.4 months. Patients who progressed or did not respond to chemotherapy had worse overall survival (P = .001) and freedom from CNS relapse (P = .005) compared with CR patients.

Conclusions

Among patients with a PR to induction chemotherapy, reduced-dose WBRT with a boost to residual PCNSL may be a viable treatment approach that merits further investigation.

The diagnostic role and dynamic changes in cerebrospinal fluid neopterin during treatment of patients with primary central nervous system lymphoma

This study aimed at evaluating the diagnostic and prognostic role of neopterin (Npt) concentration in the cerebrospinal fluid (CSF) of patients with primary central nervous system lymphoma (PCNSL). Ninety‐nine patients were enrolled in this retrospective study; these included patients with PCNSL (n = 21), other brain tumors (n = 44), and inflammatory diseases (n = 34). CSF Npt concentration was measured using ELISA. Receiver operating characteristic (ROC) curve analysis was performed to assess the discriminative ability of CSF Npt concentration for the diagnosis of PCNSL. CSF Npt concentration in patients with PCNSL was significantly higher than that in patients with other brain tumors and inflammatory diseases (P < .001). On ROC curve analysis, the optimal cutoff CSF Npt level of 10.77 ng/mL for the diagnosis of PCNSL and the diagnostic yield of MRI were increased when used in conjunction with CSF Npt concentration. The CSF Npt concentrations in PCNSL patients with multiple lesions were significantly higher than those in patients with a single lesion. Changes in CSF Npt concentration were consistent with post‐treatment changes in tumor sizes. The CSF Npt concentration may be a good biomarker for the diagnosis, for monitoring of disease course, and for prognostic evaluation of patients with PCNSL.

Methotrexate-cytarabine-dexamethasone combination chemotherapy with or without rituximab in patients with primary central nervous system lymphoma

Purpose

High-dose methotrexate based chemotherapy is the standard treatment for patients with newly diagnosed primary central nervous system lymphoma (PCNSL). The role of rituximab is controversial because of its large size, which limits its penetration of the blood-brain barrier. In this study, we investigated the efficacy and tolerability of adding rituximab to methotrexate-cytarabine-dexamethasone combination therapy (RMAD regimen).

Results

The patients treated with RMAD had a complete remission rate of 66.7% after induction chemotherapy; this rate was only 33.3% in patients treated with MAD alone (p = .011). The most common grade 1–3 adverse events were similar and included hematologic toxicity, increased aminotransferase levels, and gastrointestinal reactions. Multivariate analysis revealed that rituximab treatment was associated with longer progression-free survival (PFS, p = .005) but not overall survival (OS). Additionally, we observed that elevated serum lactate dehydrogenase was associated with shorter OS and PFS.

Materials and Methods

We retrospectively analyzed 60 immunocompetent patients with newly diagnosed PCNSL at Beijing Tiantan Hospital, Capital Medical University from January 2010 to June 2016. Twenty-four patients received 3–6 courses of 3.5 g/m² methotrexate on day 1; 0.5–1 g/m² cytarabine on day 2; and 5–10 mg dexamethasone on days 1, 2 and 3. Thirty-six patients received the same combination plus rituximab 375 mg/m² on day 0. All patients repeated the treatment every 3 weeks.

Conclusions

High-dose methotrexate based chemotherapy with rituximab yields a higher complete remission rate and does not increase serious toxicities. PFS benefits from the addition of rituximab. OS has an increasing trend in patients treated with rituximab without statistical significance.

Novel biomarker, phosphorylated T-LAK cell-originated protein kinase (p-TOPK) can predict outcome in primary central nervous system lymphoma

This study aimed to assess whether T-lymphokine-activated killer cell-originated protein kinase (TOPK) can be a potent novel biomarker to predict the outcome in patients with primary central nervous system lymphoma (PCNSL). This study enrolled 20 patients who were histologically diagnosed as having diffuse large B-cell type PCNSL between 2005 and 2015. Using surgical specimens, the expression of TOPK and phosphorylated TOPK (p-TOPK) was analyzed on immunohistochemistry. Clinical features such as age, sex, Karnofsky performance status (KPS), ocular involvement, deep brain structure involvement, the number of lesions, chemotherapy and radiation therapy were also collected. Impacts of TOPK/p-TOPK expression on their progression-free survival (PFS) and overall survival (OS) were examined with multivariate analysis. Median PFS/OS were 24.2 and 39.0 months, respectively. On immunostaining, the mean percentage of TOPK-positive cells was 35.5 ± 20.8%, and the mean number of p-TOPK-positive cells was 13.7 ± 15.7 cells/mm² . The higher expression of p-TOPK was significantly related to multiple lesions (P = 0.003). Multivariate analysis demonstrated that only the higher expression of p-TOPK was an independent predictor to shorten both PFS (P = 0.029; hazard ratio (HR), 5.5; 95% confidential interval (CI), 1.2-25.3) and OS (P = 0.014; HR, 7.7; 95% CI, 1.5-41.3). These findings strongly suggest that p-TOPK may be a potent biomarker to determine the outcome of patients with PCNSL and to develop novel drugs to treat PCNSL.

The possible role of maintenance treatment for primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive brain tumor. The prognosis is poor, with high rates of relapse and disease progression after treatment. In addition, PCNSL affects a largely older population, so that a significant proportion of patients are ineligible for intensive therapies and high-dose chemotherapy. The elderly patients are also susceptible to the accelerated and detrimental cognitive side effects of whole-brain irradiation which is an alternative consolidation to high-dose chemotherapy. Maintenance therapy has been shown to be a promising strategy to prolong remission time in other hematopoietic malignancies. Herein, we discuss the place of maintenance treatment in PCNSL in view of perspective obtained from hematological malignancies and non-Hodgkin's lymphoma.

Balancing relapses versus cognitive impairment in primary central nervous system lymphoma: a single-center experience

OBJECTIVES

The outcomes of primary central nervous system lymphoma (PCNSL) are much improved with multi-modality regimens. Unfortunately, in limited-resource countries, chemo-radiotherapy is the only option of curative-intent treatment. This study aimed to evaluate the effects of low-dose whole brain radiotherapy (WBRT) as a consolidation on disease control and long-term neurocognitive functions.

METHODS

We conducted a retrospective single-center study enrolling PCNSL patients from 2011 to May 2016 to evaluate the real-life treatment outcome and neurotoxicity from treatment especially radiotherapy.

RESULTS

Thirty-seven newly diagnosed immunocompetent PCNSL patients were treated with a high-dose methotrexate-based regimen with or without WBRT. The median age was 56 (range 16-78) years old. After chemotherapy, the overall response and complete response (CR) rates were 59.5% and 43.2%, respectively. All 6 partial response (PR) patients and 6 of 16 CR patients underwent radiotherapy. In 22 patients who achieved CR, the progression-free survival (PFS) of patients without WBRT was significantly inferior to the WBRT group with the hazard ratio of 4.7 (95% confidence interval 1.14-19.82, p = 0.03). The 3-year PFS were 35% and 78.75%, respectively, but there was no difference in overall survival. The serial Montreal Cognitive Assessment evaluations (20-72 months post chemotherapy) of 10 long-term CR patients revealed one dementia among three patients without WBRT and five mild cognitive impairments in seven patients with WBRT. Except for the dementia case, all the other patients can perform daily activities without assistance.

CONCLUSION

The low-dose WBRT consolidation is associated with lower PCNSL relapses with only mild neurocognitive toxicity.

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.

Phase II study of rituximab given in conjunction with standard chemotherapy in primary central nervous system lymphoma (PCNSL): a trial of the ECOG-ACRIN cancer research group (E1F05)

Background

Therapy of primary CNS lymphoma (PCNSL) has focused on multi-agent chemotherapy designed to cross the blood brain barrier. Rituximab has demonstrated activity in PCNSL. E1F05 is an ECOG-ACRIN multicenter phase 2 prospective trial of rituximab with high-dose methotrexate (HD-MTX)-based chemotherapy similar to the RTOG 93-10 regimen, omitting radiotherapy.

Methods

Immunocompetent patients with newly diagnosed PCNSL received HD-MTX 3.5g/m2 with vincristine every two weeks for 5 doses; procarbazine for 7 days in weeks 1, 5, and 9; cytarabine 3g/m2/day IV for 2 days in weeks 11 and 14; a dexamethasone taper over 6 weeks; and rituximab 375mg/m2 IV infusion 3 times per week for weeks 1-4. Subjects with CSF involvement received intrathecal methotrexate 12mg every two weeks.

Results

Twenty-six patients were enrolled; median age was 57. Sixteen subjects (65%) completed treatment per protocol; the most common reason for discontinuation was adverse events, and 2 subjects discontinued due to progressive disease (PD). Complete response (CR) + unconfirmed CR (CRu) was 16/25 (64%), overall response rate was 20/25 (80%), and 4/25(16%) had PD as best response. Median progression free survival (PFS) was 34 months, and median overall survival has not been reached at 40 months’ median follow up. Two year PFS was 63%. The most common grade 3-4 toxicities were hematologic.

Conclusion

The addition of rituximab to multi-agent chemotherapy is well tolerated. Outcomes are comparable to or better than those seen in RTOG 93-10, which included RT. These and other results suggest rituximab has activity in the CNS. [ECOG-ACRIN E1F05]

Clinical Trial Registration

NCT00335140, clinicaltrials.gov

Advances in the treatment of newly diagnosed primary central nervous system lymphomas

Primary central nervous system lymphoma (PCNSL) is a type of highly invasive non-Hodgkin lymphoma. With a growing number of organ transplantation and immunosuppressant therapy, the incidence of PCNSL has been growing rapidly in recent years, which is attributed to the increased incidence of HIV/AIDS, a prominent risk factor for developing PCNSL. The rising rate of PCNSL incidence is the highest among the intracranial tumors. In the past 20 years, dozens of clinical trials related to PCNSL have been registered, but adequate therapeutics are still challenging. Currently, the chemotherapy regimens based on high-dose methotrexate and whole-brain radiotherapy are the two main therapeutic options; however, the toxicity associated with those is the main problem that challenges medical researchers. Novel agents and therapeutic strategies have been developed in recent years. In the current review, we describe advances in the treatment of PCNSL and discuss novel therapeutic approaches currently in development, such as the use of rituximab, disruption of the blood-brain barrier, and state-of-the-art radiotherapy.

A single institutional retrospective evaluation for younger patients with primary central nervous lymphomas on a modified R-MPV regimen followed by radiotherapy and high dose cytarabine

We conducted a retrospective analysis of patients younger than 60 years (N = 10, median age 54.5) with newly diagnosed primary central nervous system lymphoma (PCNSL) at the University of Tsukuba Hospital from January 2008 to November 2016. All the patients were scheduled to receive a single regimen without registration to any clinical trials. This was based on a phase 2 study by Memorial Sloan-Kettering Cancer Center (MSKCC); induction chemotherapy with rituximab, methotrexate, procarbazine, and vincristine (R-MPV) (five to seven cycles), followed by whole-brain radiotherapy (rd-WBRT) (23.4 Gy) and two high-dose cytarabine (HD-AC) cycles as a consolidation. The median age was 54.5 years, and median follow up duration was 33.1 months. The 3-year overall survival (OS) and progression-free survival (PFS) were 69% (95% CI 31-89%) and 56% (95% CI 20-81%). The median OS and PFS were not reached, respectively. Acute and delayed toxicities were manageable. In particular, OS and PFS of seven patients who achieved CR by the R-MPV induction chemotherapy were significantly superb (3-year OS, 100%; 3-year PFS, 80%), implying that a large proportion of patients in CR after the completion of this treatment may achieve durable disease control. On the other hand, all of the three patients who had progressive disease during this treatment died of disease progression within 1 year after diagnosis without achieving CR. Identifying the patients having a risk of failure in the R-MPV induction chemotherapy is important, and may allow us to consider a potentially more effective regimen.

Case-based review: primary central nervous system lymphoma

Primary CNS lymphoma (PCNSL) is a rare diffuse large B-cell lymphoma originating within the central nervous system. The overall incidence of PCNSL is rising, particularly in the elderly population. Immunosuppression is a strong risk factor, but most patients with this tumor are apparently immunocompetent. Diagnosis of PCNSL can be challenging. Non-invasive or minimally invasive tests such as ophthalmological evaluation and spinal fluid analysis may be useful, but the majority of patients require tumor biopsy for definitive diagnosis. Our knowledge concerning optimum treatment of PCNSL is fragmentary due to paucity of adequately sized trials. Most patients are now initially treated with high-dose-methotrexate-based chemotherapy alone, as the addition of whole-brain radiotherapy at standard doses has not been shown to increase survival and does increase the risk of neurological toxicity. Ongoing trials are addressing issues such as the roles of reduced-dose radiotherapy, the addition of the CD20 antibody rituximab to chemotherapy, high-dose chemotherapy followed by autologous stem cell transplantation, and maintenance therapy in the primary management of PCNSL.

Role of rituximab in treatment of patients with primary central nervous system lymphoma: a retrospective analysis of the Czech lymphoma study group registry

We have investigated whether the addition of rituximab to methotrexate, procarbazine, vincristine, radiotherapy and cytarabine was associated with improved outcome of primary central nervous system lymphomas (PCNSL). Of 164 patients, 49 received rituximab. Median age was 63 years, median Karnofsky performance score (KPS) was 60 and median follow-up of living patients was 59.5 months. 1- and 2-year PFS were 49.7 and 37.9%, 1- and 2-year OS were 57.0 and 45.3%. Median progression-free survival (PFS), but not overall survival (OS) was significantly better for patients treated with rituximab (22.9 vs. 10.9 months, p = 0.037). In multivariate analysis, age ≤70 years and KPS ≥90 were predictive for PFS and OS, rituximab was an independent prognostic factor for PFS only. In landmark analyses, rituximab was not found beneficial for long-term survivors and no group particularly benefited from rituximab. In conclusion, addition of rituximab was associated with improved PFS, but not OS in this unselected cohort of PCNSL patients.

Primary central nervous system lymphoma treated with high-dose methotrexate and rituximab: A single-institution experience

Rituximab (RTX) improves the outcome in patients with systemic diffuse large B-cell lymphoma (DLBCL), but its benefit in primary central nervous system lymphoma (PCNSL) is unclear. In the present study, a single-institution retrospective analysis was performed for 12 patients with newly diagnosed PCNSL treated with combined high-dose methotrexate (HD-MTX) and RTX. MTX was administered biweekly at 8 g/m²/dose until a complete response (CR) was achieved or for a maximum of eight doses. RTX was provided for a total of eight weekly doses at 375 mg/m²/dose. Following a median of 11 cycles of MTX, the radiographic overall response rate was 91% and the CR rate was 58%. A CR was achieved after a median 6 cycles of MTX. The median progression-free survival time was 22 months and the median overall survival time has not yet been attained. These results compare favorably to single-agent HD-MTX and suggest a role for immunochemotherapy in the treatment of PCNSL.

Central nervous system involvement by Waldenström macroglobulinaemia (Bing-Neel syndrome): a multi-institutional retrospective study

Bing-Neel syndrome (BNS) is a rare complication seen in patients with Waldenström macroglobulinaemia (WM), in which lymphoplasmacytic lymphoma cells colonize the central nervous system. In this retrospective multi-centre study, we present the clinicopathological features, imaging findings, therapy, response and outcomes of 34 patients with BNS. The median time from WM diagnosis to BNS diagnosis was 3 years, 15% of patients were diagnosed with BNS at the time of WM diagnosis, and 22% of patients developed BNS when responding to active treatment for WM. Patients with BNS presented with variable clinical features including limb motor deficits, change in mental status and cranial nerve palsies. The diagnosis was made using a combination of cerebrospinal fluid cytology, flow cytometry and detection of the MYD88 L265 mutation, and magnetic resonance imaging. The estimated 3-year overall survival rate was 59%. Of the survivors, 40% have evidence of pathological and/or radiological persistence of disease. Age older than 65 years, platelet count lower than 100 × 10(9) /l, and treatment for WM prior to BNS diagnosis were associated with worse outcome. Exposure to rituximab for treatment of BNS was associated with a better outcome. Multi-institutional collaboration is warranted to improve treatment and outcomes in patients with BNS.

High-dose cytarabine salvage therapy for recurrent primary CNS lymphoma

Treatment of recurrent primary CNS lymphoma (PCNSL) though not standardized most often utilizes whole brain radiotherapy, re-challenge with high-dose methotrexate, or administration of an alkylating chemotherapy. High-dose cytarabine (HD-araC) has been advocated as an active agent in PCNSL but limited information exists regarding single agent activity in the recurrent setting. A retrospective review of 14 patients (10 males, 4 females: median age 60 years) with recurrent PCNSL treated at second recurrence with single agent HD-araC. HD-araC was administered at 3gm/m(2) over a 3-h infusion every 12 h for a total of 4 doses (defined as a cycle of therapy). GM-CSF was administered at conclusion of HD-araC. Patients were clinically and radiographically evaluated every 4-weeks. Common toxicity criteria Grade 3 or 4 toxicity included thrombocytopenia (11 patients; 79%), anemia (10; 71%), fatigue (8; 57%), mucositis (8; 57%), neutropenia (8; 57%) and neutropenic fever (5; 36%). No patient discontinued therapy due to toxicity nor were there any treatment-related deaths. Best response to HD-araC was stable disease in 6 patients (43%), partial response in 5 (36%) and progressive disease in 3 (21%). Median progression free survival 3 months (range 2-5 months; 95% CI 2-4 months) and progression free survival was 0% at 6-months. Median survival after onset of HD-araC was 12 months (range 3-18+ months; 95% CI 3-15 months). Single agent HD-araC has limited activity in recurrent PCNSL and is associated with significant toxicity in this small retrospective study.

HIV-related hematological malignancies: a concise review

HIV (Human Immunodeficiency Virus) and its consequence, AIDS (acquired immunodeficiency syndrome) are responsible for a human tragedy of incalculable proportions. Patients afflicted by it are susceptible due to an early senescence of the immune system to opportunistic infections and malignancies. Since the introduction in 1996 of highly active anti-retroviral therapy (HAART), the landscape of malignancies associated to HIV/AIDS has changed in a significant manner as a direct result of significant improvement in the morbidity, mortality and life expectancy of HIV infected patients. While there has been a significant decrease in developed countries of malignancies such as Kaposi's sarcoma and Primary CNS lymphomas associated to the pre-HAART HIV-related immunodeficiency, hematological malignancies, particularly non-Hodgkin lymphomas continue to be the most common cancer-related cause of death in HIV infected individuals. This concise review of the subject highlights aspects of the natural history of HIV disease as it relates to the cause of malignancies with emphasis in the management and treatment of HIV-related hematological malignancies.

Objective cerebrospinal fluid response to intraventricular rituximab in indolent CNS lymphoma

Indolent CNS lymphomas (CNSLs) are rare and no guidelines exist for management. Recent literature highlights the potential for safe and tolerable intrathecal (IT) delivery of rituximab, a large anti-CD20 monoclonal antibody, for aggressive CNSL. We report a patient with relapsed indolent CNSL who failed systemic rituximab and could not tolerate IT chemotherapies, but had an objective response of 6 months duration to IT rituximab.

Primary central nervous system lymphoma: current state of anti-CD20 therapy and appraisal of reported response criteria

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin's lymphoma which is confined to the central nervous system and may also affect intraocular structures. Despite high initial rates of response to methotrexate-based chemotherapy, more than 50% of patients will experience relapse and about 10% have disease that is refractory to chemotherapy. Outcome in patients who fail treatment is very poor, and therefore new therapeutic approaches that may increase the rate of complete response and the proportion of durable remission are sought. Based on the pivotal role that anti-CD20 therapy now plays in the treatment outcome of aggressive systemic B-cell lymphomas, a similar approach is commonly being adapted for PCNSL despite the lack of evidence for its effectiveness. This review examines the current status and level of evidence for the use of monoclonal antibodies against the CD20 surface antigen, which is present on normal and malignant B-cells in PCNSL. The review covers both systemic and local (intracerebrospinal fluid or intravitreal) administration of CD20 monoclonal antibodies in PCNSL. In addition, it scrutinizes the response criteria commonly reported for evaluation of treatment outcome. The importance of differentiating unconfirmed complete response from partial response is outlined and the lack of consensus on response criteria for atypical imaging presentations of PCNSL is delineated.

High-dose methotrexate with or without rituximab in newly diagnosed primary CNS lymphoma

OBJECTIVE

To evaluate the efficacy of rituximab (R) when added to high-dose methotrexate (HD-MTX) in patients with newly diagnosed immunocompetent primary CNS lymphomas (PCNSLs).

METHODS

Immunocompetent adults with newly diagnosed PCNSL treated at The Johns Hopkins Hospital between 1995 and 2012 were investigated. From 1995 to 2008, patients received HD-MTX monotherapy (8 g/m2 initially every 2 weeks and after complete response [CR] monthly to complete 12 months of therapy). From 2008 to 2012, patients received the same HD-MTX with rituximab (375 mg/m2) with each HD-MTX treatment. CR rates and median overall and progression-free survival were analyzed for each patient cohort in this single-institution, retrospective study.

RESULTS

A total of 81 patients were identified: 54 received HD-MTX (median age 66 years) while 27 received HD-MTX/R (median age 65 years). CR rates were 36% in the HD-MTX cohort and 73% in the HD-MTX/R cohort (p = 0.0145). Median progression-free survival was 4.5 months in the HD-MTX cohort and 26.7 months in the HD-MTX/R cohort (p = 0.003). Median overall survival was 16.3 months in the HD-MTX cohort and has not yet been reached in the HD-MTX/R cohort (p = 0.01).

CONCLUSIONS

The addition of rituximab to HD-MTX appears to improve CR rates as well as overall and progression-free survival in patients with newly diagnosed PCNSL. Comparisons of long-term survival in the 2 cohorts await further maturation of the data.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in immunocompetent patients with PCNSL, HD-MTX plus rituximab compared with HD-MTX alone improves CR and overall survival rates.

Clinical outcomes of patients with newly diagnosed primary central nervous system lymphoma are comparable on treatment with high-dose methotrexate plus temozolomide and with high-dose methotrexate plus cytarabine: a single-institution experience

The role of temozolomide in untreated PCNSL patients has not yet been clearly defined. The purpose of this study was to compare the efficacy and toxicity of MT and MC chemotherapy in this population. A total of 41 consecutive patients were enrolled from March 2001 to July 2011. The ORR and CRR for MT vs. MC were 70% vs. 61.9% and 45% vs. 38.1% on ITT basis, (p = NS); 73.7% vs. 68.4% and 47.4% vs. 42.1% on PP basis, respectively (p = NS). Grade 3-4 hematological toxicities were more common in MC than in MT group (85.7% vs. 15%, p = 0.0001). One treatment-related death was observed in each group. The 5-year PFS and OS of MT (36% and 62.2%) were comparable to MC (32.6% and 46.7%), (p = NS). In summary, our preliminary results suggest that MT combination may be a simplified and effective regimen comparable to MC for newly diagnosed PCNSL.