Primary central nervous system lymphoma: the Memorial Sloan-Kettering Cancer Center prognostic model

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.

Rituximab is associated with improved survival for aggressive B cell CNS lymphoma

BACKGROUND

The optimal treatment strategy in patients with aggressive B cell central nervous system lymphoma suitable to receive intensive therapy is unknown. The benefit of incorporating rituximab in systemic therapy remains unclear. We performed a retrospective study examining the impact of rituximab in the context of concomitant therapies, including methotrexate, cytarabine, and radiotherapy, in patients treated with curative intent at 4 university teaching hospitals during 1996-2011.

METHODS

A retrospective study of CNS lymphoma cases treated at the participating institutions was performed in accordance with institutional ethical guidelines. Patients were included if they received a diagnosis of primary diffuse large B cell lymphoma of the CNS, were HIV negative, and were treated with curative intent.

RESULTS

One hundred twenty patients aged 21-81 years were identified. Rituximab recipients and nonrecipients were similar, except for rituximab recipients being more likely to have received a diagnosis after 2004. The median follow-up of surviving patients was 30 months. The 5-year overall survival was 46%. Univariate analysis revealed age ≤60 years, ECOG performance status ≤1, normal lactate dehydrogenase, diagnosis after 2004, and treatment with cytarabine and rituximab as predictive of favorable overall survival. Multivariate analysis identified age to be an independent predictor of overall survival, with a trend toward improved survival from the other variables that were significant in univariate analyses.

CONCLUSIONS

In this retrospective analysis, the addition of rituximab to high-dose methotrexate-based chemotherapy in patients with aggressive B cell CNS lymphoma was associated with improved overall survival. Further studies are underway to prospectively validate these findings.

Prognosis of patients with primary central nervous system lymphoma after high-dose chemotherapy followed by autologous stem cell transplantation

High-dose chemotherapy followed by autologous stem cell transplantation has been shown to be feasible and highly effective in newly diagnosed primary central nervous system lymphoma. In this retrospective multicenter study, we investigated prognosis and baseline risk factors in patients with primary central nervous system lymphoma who underwent this treatment approach. We retrospectively analyzed 105 immunocompetent patients with primary central nervous system lymphoma who underwent high-dose chemotherapy followed by autologous stem cell transplantation with or without whole brain radiotherapy as first-line consolidation treated at 12 German centers between 1997 and 2011. We estimated survival rates and investigated the impact of age, performance status, serum lactate dehydrogenase level, and deep brain involvement on overall and progression-free survival. Patients were additionally categorized into three prognostic groups according to the Memorial Sloan Kettering Cancer Center prognostic model. After a median follow up of 47 months, median progression-free survival and overall survival was reached after 85 and 121 months; 2- and 5-year survival rates were 82% and 79%, respectively. The Memorial Sloan Kettering Cancer Center prognostic model did not predict survival. Only age revealed some evidence of prognostic relevance. Overall response rate was 95%; of those patients with progressive disease before high-dose chemotherapy, 7 of 20 achieved ongoing complete remission after therapy without whole brain radiation therapy. Transplantation-associated mortality was 2.8%. High-dose chemotherapy followed by autologous stem cell transplantation is a highly effective and safe treatment modality for selected primary central nervous system lymphoma patients. Superiority compared to standard chemotherapy still warrants further investigation.

18F-FDG PET is an independent outcome predictor in primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma is an aggressive non-Hodgkin lymphoma with poor prognosis. We evaluated pretreatment (18)F-FDG PET as a prognostic marker in primary CNS lymphoma.

METHODS

Forty-two immunocompetent patients with newly diagnosed primary CNS lymphoma who underwent pretreatment (18)F-FDG PET were retrospectively analyzed. Baseline status and response to treatment were evaluated by MR imaging. Tumor maximum standardized uptake values were assessed by volume-of-interest analyses using an automatic isocontour definition. A 10-step semiquantitative visual rating system (metabolic imaging lymphoma aggressiveness scale, or MILAS) was used to assess primary CNS lymphoma metabolism as a marker of clinical aggressiveness. Logistic regression, log-rank testing, and multivariable Cox regression were used to investigate the association between (18)F-FDG uptake and tumor response and survival.

RESULTS

Mean maximum standardized uptake value correlated linearly with MILAS. The distribution of patients according to MILAS (0-9) was 0%, 28.6%, 23.8%, 21.4%, 11.9%, 4.8%, 7.1%, 0%, 0%, and 2.4%. There was no correlation between MILAS and response to treatment. Respective 2- and 5-y survival rates were 52% and 32% for progression-free survival (PFS) and 64% and 50% for overall survival (OS). A cutoff at MILAS 3 was a good separator for PFS (median: 54.7 mo [≤3], 3.8 mo [>3], P = 0.0272) and OS (median: not reached [≤3], 13.8 mo [>3], P = 0.131). In multivariable analyses, increasing MILAS was significantly associated with shorter PFS (hazard ratio, 1.49, P = 0.006) and OS (hazard ratio, 1.43, P = 0.018).

CONCLUSION

Increased pretreatment (18)F-FDG uptake may offer new opportunities for baseline risk evaluation in untreated primary CNS lymphoma.

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.

Association of transcobalamin c. 776C>G with overall survival in patients with primary central nervous system lymphoma

Background:

Chemotherapy for primary central nervous system lymphoma (PCNSL) is based on methotrexate (MTX), which interferes with both nucleic acid synthesis and methionine metabolism. We have reported previously that genetic variants with influence on methionine metabolism are associated with MTX side effects, that is, the occurrence of white matter lesions as a sign of MTX neurotoxicity. Here, we investigated whether such variants are associated with MTX efficacy in terms of overall survival in MTX-treated PCNSL patients.

Methods:

We analysed seven genetic variants influencing methionine metabolism in 68 PCNSL patients treated with systemic and facultative intraventricular MTX-based polychemotherapy (Bonn protocol).

Results:

Median age at diagnosis was 59 years (range: 28–77), 32 patients were female. Younger age (Wald=8.9; P=0.003) and the wild-type C (CC) allele of the genotype transcobalamin c (Tc2). 776C>G (Wald=6.7; P=0.010) were associated with longer overall survival in a multivariate COX regression analysis.

Conclusion:

This observation suggests that the missense variant Tc2. 776C>G influences both neurotoxicity and efficacy of MTX in the Bonn PCNSL protocol.

Outcomes of the oldest patients with primary CNS lymphoma treated at Memorial Sloan-Kettering Cancer Center

Up to 20% of all primary CNS lymphoma (PCNLS) patients are aged 80 years or older, yet data are limited on how best to treat this rapidly growing population. Despite demographic pressures and the proven efficacy of methotrexate (MTX)-based regimens, automatic de-escalation of care based on age is standard practice outside of tertiary care centers. We performed a retrospective review of all PCNSL patients aged 80 years or older treated at Memorial Sloan-Kettering Cancer Center from 1993 to 2011. Demographic and clinical variables were evaluated as predictors of survival by multivariate analysis. Twenty-three of 24 patients were treated with chemotherapy (92% with high-dose MTX, typically in combination with vincristine and procarbazine). One patient received ocular radiation alone for disease limited to the eyes. Response to treatment was noted in 62.5% of patients; 9 (37.5%) had refractory disease. Median overall survival was 7.9 months (95% confidence interval [CI]: 5.8-53), and median progression-free survival was 6.5 months (95% CI: 4.4-29.5). Two-year survival rate was 33%; 3-year survival rate was 17%. Three patients lived more than 4 years postdiagnosis. Most patients tolerated therapy well, and despite low baseline creatinine clearance, no significant renal toxicity was noted. Response status and deep brain involvement were identified as the most important predictors of survival. Multidrug regimens containing high-dose MTX are feasible and efficacious among the oldest patients, particularly those who achieve a complete response by their fifth treatment cycle. Aggressive therapy should be offered to select patients irrespective of advanced age.

Pathogenesis and management of primary CNS lymphoma

Primary CNS lymphoma (PCNSL), a rare variant of extranodal non-Hodgkin's lymphoma, may cause various neurological symptoms and signs. The best therapeutic strategy is still a matter of debate. High-dose methotrexate (HD-MTX) is the most active compound and should be used as the backbone for any chemotherapy applied. Several other chemotherapeutic drugs have been assessed in combination with HD-MTX, but no standard has yet been defined. Whole-brain radiotherapy is active against PCNSL, but typically does not confer long-lasting remission and is associated with significant neurotoxicity in many patients. The recently published G-PCNSL-SG1 trial has shown that consolidating whole-brain radiotherapy after HD-MTX-based chemotherapy does not prolong overall survival and may therefore be deferred. Combined systemic and intraventricular polychemotherapy, or high-dose chemotherapy followed by stem cell transplantation may offer cures to younger patients. Improving treatment regimens without adding significant (neuro-)toxicity should be the focus of ongoing and future studies.

Central nervous system marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type involving the brain and spinal cord parenchyma

We present a case of a 53-year-old HIV negative man with a 2-month history of progressive recent memory disturbance, gait disturbance and urinary incontinence. On MRI, an infiltrative tumor in the brain and spinal cord was noted. Subsequent positron emission tomography studies along with bone marrow biopsy and serum protein electrophoresis showed no evidence of systemic disease. Open brain biopsy results revealed a small lymphocytic infiltrate with scattered plasma cells in a predominantly perivascular growth pattern. The morphology was consistent with involvement by a low-grade B-cell lymphoma. Immunohistochemical findings showed CD20+, CD10-, CD5-, TdT-, EBV-encoded RNA in situ- and IgM-. The above findings were consistent with involvement by a non-dural extranodal marginal zone B-cell lymphoma (MZBCL) primary to the brain and spinal cord. This is a case report of a CNS MZBCL of mucosa-associated lymphoid tissue type involving the brain and spinal cord parenchyma.

Prognostic impact of meningeal dissemination in primary CNS lymphoma (PCNSL): experience from the G-PCNSL-SG1 trial

BACKGROUND

We evaluated the frequency and prognostic impact of meningeal dissemination (MD) in immunocompetent adult patients with primary central nervous system lymphoma treated in a randomized phase III trial.

PATIENTS AND METHODS

MD was evaluated at study entry and defined by lymphoma proof in the meningeal compartment detected by at least one of the following methods: cerebrospinal fluid (CSF) cytomorphology, detection of clonal B cells by IgH PCR in CSF or contrast enhancement of the leptomeninges on magnetic resonance imaging (MRI).

RESULTS

Data on MD were available in 415 patients, of those, MD was detected in 65 (15.7%): in 44/361 (12.2%) by CSF cytomorphology, in 16/152 (10.5%) by PCR and in 17/415 (4.1%) by MRI. Major patients' characteristics and therapy did not significantly differ between patients with MD (MD+) versus those without MD (MD-). There was a significant correlation of MD with CSF pleocytosis (>5/μl; P < 0.0001), but no correlation with CSF protein elevation (>45 mg/dl). Median progression-free survival was 6.7 months [95% confidence interval (CI) 0-14.5] in MD+ and 8.3 months (5.7-10.8) in MD- patients (P = 0.95); median overall survival was 21.5 months (95% CI 16.8-26.1) and 24.9 months (17.5-32.3), respectively (P = 0.98).

CONCLUSION

MD was detected infrequently and had no impact on outcome in this trial.

Gene expression signature-based prognostic risk score in patients with primary central nervous system lymphoma

PURPOSE

Better understanding of the underlying biology of primary central nervous system lymphomas (PCNSL) is critical for the development of early detection strategies, molecular markers, and new therapeutics. This study aimed to define genes associated with survival of patients with PCNSL.

EXPERIMENTAL DESIGN

Expression profiling was conducted on 32 PCNSLs. A gene classifier was developed using the random survival forests model. On the basis of this, prognosis prediction score (PPS) using immunohistochemical analysis is also developed and validated in another data set with 43 PCNSLs.

RESULTS

We identified 23 genes in which expressions were strongly and consistently related to patient survival. A PPS was developed for overall survival (OS) using a univariate Cox model. Survival analyses using the selected 23-gene classifiers revealed a prognostic value for high-dose methotrexate (HD-MTX) and HD-MTX-containing polychemotherapy regimen-treated patients. Patients predicted to have good outcomes by the PPS showed significantly longer survival than those with poor predicted outcomes (P < 0.0001). PPS using immunohistochemical analysis is also significant in test (P = 0.0004) and validation data set (P = 0.0281). The gene-based predictor was an independent prognostic factor in a multivariate model that included clinical risk stratification (P < 0.0001). Among the genes, BRCA1 protein expressions were most strongly associated with patient survival.

CONCLUSION

We have identified gene expression signatures that can accurately predict survival in patients with PCNSL. These predictive genes should be useful as molecular biomarkers and they could provide novel targets for therapeutic interventions.

Current and emerging pharmacotherapies for primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) constitutes a rare group of extranodal non-Hodgkin's lymphoma (NHL) primarily of B cell origin. It occurs in both immuno-competent and immune-compromised patients. High dose m ethotrexate (HD-MTX) based chemotherapy is the standard therapy. Chemotherapy with whole brain radiation therapy (WBRT) improves response rates and survival compared with WBRT alone. However, due to the increased risk for neurotoxicity with WBRT, recent studies have focused on using chemotherapy alone. Methotrexate based multi-agent chemotherapy without WBRT is associated with similar t reatment rates and survival compared with regimens that include WBRT although controlled trials have not been performed. Because of the low incidence of this disease, it is difficult to conduct randomized controlled trials. In this article we have discussed about the past, present and emerging treatment options in patients with PCNSL.

The prognostic value of serum methotrexate area under curve in elderly primary CNS lymphoma patients

Studies on pharmacokinetics and pharmacodynamics of high-dose methotrexate chemotherapy (HD-MTX) in elderly primary central nervous system lymphoma (PCNSL) patients are rare. MTX exposure time has recently been proposed as an outcome determining factor in PCNSL. We investigated 49 immunocompetent PCNSL patients (female N=30, male N=19, median age 73 years) who were treated according to HD-MTX-based protocols. A two-compartment pharmacokinetic model was used to describe the MTX clearance. Response to treatment was assessed by MRI. We used multivariable models to investigate the association between MTX exposure and tumor response as well as survival. Dose normalized MTX peak serum levels [C (max), μmol/L g] and dose normalized area under the curve [AUC(dn), μmol h/L g] were higher in females than in males, respectively [59.4 (f) vs. 48.1 (m), P<0.001; 373.2 (f) vs. 271.9 (m), P=0.008]. Increasing AUC was inversely correlated with tumor response. AUC values above 2,126 h μmol/L were independently associated with shorter overall and progression-free survival [hazard ratio (HR), 4.56, 95 % CI 1.74-11.94; HR 2.87, 95 % CI 1.18-7.00]. Exceedingly high MTX AUC levels can have a negative impact on progression-free and overall survivals in elderly PCNSL patients.

Relapse pattern and prognostic factors for patients with primary central nervous system lymphoma

Background

Primary central nervous system lymphoma (PCNSL) rarely relapses in extracranial sites, and no specialized guidelines for follow-up evaluation have been proposed.

Methods

We analyzed 65 patients with newly diagnosed PNCSL to evaluate the pattern of relapse and prognostic factors.

Results

Of the 65 patients analyzed, 55 had only parenchymal brain disease, and 10 had both intracranial and extracranial lesions. As a first-line treatment, 29 patients received chemotherapy only (CTx), 13 received chemotherapy followed by whole brain radiotherapy (CTx-WBRT), 18 received chemotherapy followed by autologous stem cell transplantation (CTx-ASCT), 2 received palliative WBRT, and 3 received best supportive care. The overall response rate to the initial treatment was 75.8%, with specific response rates of 62.1% to CTx, 84.6% to CTx-WBRT, and 100% to CTx-ASCT. The complete response (CR) rate was higher with CTx-ASCT than in the absence of ASCT (77.8% vs. 43.2%; P=0.025). After a median follow-up of 18.8 months, the median failure-free survival (FFS) and overall survival (OS) were 13.0 and 36.1 months, respectively. No systemic relapse without a CNS lesion was noted. Multivariate analysis showed that ASCT was predictive of better FFS but not of OS. Age and the Memorial-Sloan Kettering Cancer Center prognostic score were predictive of survival.

Conclusion

We observed no systemic relapse without a CNS lesion, suggesting that regular systematic evaluation of extracranial sites may not always be necessary. Age was prognostic of survival irrespective of treatment scheme. ASCT may improve CR rate and FFS.

Immunochemotherapy with intensive consolidation for primary CNS lymphoma: a pilot study and prognostic assessment by diffusion-weighted MRI

PURPOSE

We evaluated a novel therapy for primary central nervous system lymphoma (PCNSL) with induction immunochemotherapy with high-dose methotrexate, temozolomide, and rituximab (MT-R) followed by intensive consolidation with infusional etoposide and high-dose cytarabine (EA). In addition, we evaluated the prognostic value of the minimum apparent diffusion coefficient (ADC(min)) derived from diffusion-weighted MRI (DW-MRI) in patients treated with this regimen.

EXPERIMENTAL DESIGN

Thirty-one patients (median age, 61 years; median Karnofsky performance score, 60) received induction with methotrexate every 14 days for 8 planned cycles. Rituximab was administered the first 6 cycles and temozolomide administered on odd-numbered cycles. Patients with responsive or stable central nervous system (CNS) disease received EA consolidation. Pretreatment DW-MRI was used to calculate the ADC(min) of contrast-enhancing lesions.

RESULTS

The complete response rate for MT-R induction was 52%. At a median follow-up of 79 months, the 2-year progression-free and overall survival were 45% and 58%, respectively. For patients receiving EA consolidation, the 2-year progression-free and overall survival were 78% and 93%, respectively. EA consolidation was also effective in an additional 3 patients who presented with synchronous CNS and systemic lymphoma. Tumor ADC(min) less than 384 × 10(-6) mm(2)/s was significantly associated with shorter progression-free and overall survival.

CONCLUSIONS

MT-R induction was effective and well tolerated. MT-R followed by EA consolidation yielded progression-free and overall survival outcomes comparable to regimens with chemotherapy followed by whole-brain radiotherapy consolidation but without evidence of neurotoxicity. Tumor ADC(min) derived from DW-MRI provided better prognostic information for PCNSL patients treated with the MTR-EA regimen than established clinical risk scores.

Current strategies in the diagnosis of diffuse large B-cell lymphoma of the central nervous system

Lymphomas can arise within the central nervous system (CNS) as primary CNS lymphoma (PCNSL) typically involving the brain and less often the leptomeninges, eyes, and spinal cord. In contrast to PCNSL, secondary CNS lymphoma (SCNSL) is considered to originate as quasi metastasis from systemic lymphoma spreading to the CNS. Both types of CNS lymphomas are predominantly tumours of the diffuse large B-cell type and represent aggressive diseases necessitating a rapid diagnosis. Following neuroimaging based on magnetic resonance imaging, stereotaxy and histopathological diagnosis of CNS lymphoma currently remain obligatory to plan treatment. However, progress in cytopathological, immunophenotypic, and molecular genetic analyses of the cerebrospinal fluid (CSF) has been achieved recently and potentially will facilitate lymphoma diagnosis in the future. This review describes the diagnostic procedures in patients with suspected CNS lymphomas, primarily PCNSL. In addition to a summary of the standard diagnostic work-up, an overview and discussion of current data on different techniques for evaluation of the CSF in CNS lymphoma are given.

Neuro-oncology: a selected review of ASCO 2011 abstracts

American Society of Clinical Oncology (ASCO), the largest clinical oncology meeting in the USA, meets annually and consistently provides an exciting forum to present new cancer clinical trials and research data. The ASCO 2011 neuro-oncology session, comprising of 3 days of presentations and over 100 abstracts, provided an overview of neuro-oncology, including both metastatic diseases of the CNS and primary brain tumors. This brief article attempts to highlight select abstracts presented at this years meeting in an organizational manner that will hopefully provide a portrait of the large and multifaceted meeting.

[Management of primary central nervous system lymphoma]

Primary CNS lymphoma is the malignant brain tumor whose prognosis has improved the most the two past decades. The majority of the patients achieve a complete remission with treatment and a substantial minority may hope to be cured. The treatment includes high-dose methotrexate polychemotherapy combined or not with whole brain radiotherapy (WBRT). Elderly patients who are exposed to a high risk of treatment induced neurotoxicity need a specific management avoiding or defering WBRT. In young patients, the main questions concerning the treatment are the role of consolidation WBRT and intensive chemotherapy with peripheral blood stem cell rescue in the initial treatment of PCNSL. As recently shown, national and international collaborative efforts make now possible randomized trials for this rare disease, which would contribute to better define the treatment strategy. New insights in PCNSL tumorigenesis would help to better understand the heterogeneity of outcome and to develop efficient targeted therapies.

Clinical behavior and treatment outcome of primary nasal diffuse large B-cell lymphoma

BACKGROUND

Nasal diffuse large B-cell lymphoma (DLBCL) is rare. The objective of this study was to evaluate the clinical features and treatment outcomes of patients with nasal DLBCL.

METHODS

Twenty-five patients were included in the study. All patients received combination chemotherapy with or without radiotherapy.

RESULTS

Patients with nasal DLBCL usually were older and were predominantly men with early stage disease, low frequency of B symptoms and elevated lactate dehydrogenase (LDH), good performance status, and a low-risk international prognostic index (IPI) score. The overall response rate after initial treatment was 76%, the 3-year overall survival (OS) rate for the whole group was 44%, and the median OS was 35 months. Performance status and IPI were significant prognostic factors for OS. For patients with IPI scores of 0 or 1, the 3-year OS rate was 54%, and the median OS was 52 months compared with 17% and 11 months, respectively, for patients with IPI scores of 2 or 3 (P = .033). The prognosis for patients who achieved a complete response (CR) was significantly better than that for patients who did not achieve a CR. Extranodal spread was the primary pattern of failure.

CONCLUSIONS

The current results indicated that primary nasal DLBCL appears to have distinct clinical features; its poor outcome and propensity for extranodal failure illustrate the need for innovative therapies.

Modern concepts in the biology, diagnosis, differential diagnosis and treatment of primary central nervous system lymphoma

Recent studies addressing the molecular characteristics of PCNSL, which is defined as malignant B-cell lymphoma with morphological features of DLBCL, have significantly improved our understanding of the pathogenesis of this lymphoma entity, which is associated with an inferior prognosis as compared with DLBCL outside the CNS. This unfavorable prognosis stimulated intense efforts to improve therapy and induced recent series of clinical studies, which addressed the role of radiotherapy and various chemotherapeutic regimens. This review combines the discussion of diagnosis, differential diagnosis and recent progress in studies addressing the molecular pathogenesis as well as therapeutic options in PCNSL.

How I treat primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is a rare malignancy with peculiar clinical and biologic features, aggressive course, and unsatisfactory outcome. It represents a challenge for multidisciplinary clinicians and scientists as therapeutic progress is inhibited by several issues. Molecular and biologic knowledge is incomplete, limiting the identification of new therapeutic targets, and the particular microenvironment of this malignancy, and sanctuary sites where tumor cells grow undisturbed, strongly affects treatment efficacy. Moreover, active treatments are known to be associated with disabling neurotoxicity, posing the dilemma of whether to intensify therapy to improve the cure rate or to de-escalate treatment to avoid sequels. The execution of prospective trials is also difficult because of the rarity of the tumor and the impaired general condition and poor performance status of patients. Thus, level of evidence is low, with consequent uncertainties in therapeutic decisions and lack of consensus on primary endpoints for future trials. Despite this unfavorable background, laboratory and clinical researchers are coordinating efforts to develop new ideas, resulting in the recent publication of studies on PCNSL's biology and molecular mechanisms and of the first international randomized trials. Herein, these important contributions are analyzed to provide recommendations for everyday practice and the rationale for future trials.

Primary CNS lymphoma

Primary CNS Lymphoma (PCNSL) accounts for 3% of all primary brain tumors with a median age at onset of about 62 years. In the vast majority of cases, PCNSL presents as unifocal or multifocal enhancing lesions on MRI, frequently adjacent to the ventricles. Stereotactic biopsy is the diagnostic procedure of choice revealing high-grade malignant non-Hodgkin's B-cell lymphoma in more than 90% of cases. Therapy is not evidence based. When eligible, patients should be included in clinical trials. In patients younger than 60 years cure is the aim. Polychemotherapy based on high-dose methotrexate (MTX) or alternatively high-dose chemotherapy with autologous stem cell rescue should be offered to patients eligible for this regimens. For patients over 60 years of age no curative regimen with acceptable toxicity has yet been established. An MTX-based chemotherapy, for example, in combination with temozolomide, is recommended. The role of radiotherapy as part of the initial treatment is not established; however, the combination of radiotherapy with MTX-based chemotherapy potentially leads to severe long-term neurotoxic sequelae. Therefore, radiotherapy as part of the initial therapy is not recommended by the author outside clinical trials. At relapse or in cases of refractory disease, patients will frequently benefit of salvage therapy, which depends on the initial treatment.

Long-term survival in patients with newly diagnosed primary central nervous system lymphoma treated with dexamethasone, etoposide, ifosfamide and carboplatin chemotherapy and whole-brain radiation therapy

In the present study, we aimed to evaluate the safety and efficacy of DeVIC (dexamethasone, etoposide, ifosfamide and carboplatin) chemotherapy for the treatment of patients with primary central nervous system lymphoma (PCNSL). We retrospectively examined 21 patients with newly diagnosed PCNSL who received DeVIC chemotherapy followed by whole-brain radiation therapy (WBRT). The median progression-free survival (PFS) in all patients was 37.4 months and the median duration of overall survival (OS) was 47.8 months. Notably, the median duration of OS was significantly longer in patients who achieved a complete response (CR) after DeVIC chemotherapy (49.0 months) than in those without CR (12.8 months). Furthermore, we found that the overall response rate to the initial DeVIC chemotherapy was 95.2%. No treatment-related deaths were observed. Our study investigated the efficacy of DeVIC chemotherapy in PCNSL patients, and found it to result in favorable survival outcomes in these patients, thus warranting further investigation of it as a therapeutic measure against PCNSL.

Methotrexate area under the curve as a prognostic factor in primary central nervous system lymphoma treated with immunochemoradiotherapy

A higher methotrexate area under the curve (MTX AUC) observed during the first chemotherapy cycle has been associated with improved tumor control in patients with primary central nervous system lymphoma. To confirm these findings, we conducted a post hoc analysis of data from a prospective phase II trial of rituximab, methotrexate, procarbazine, vincristine, cytarabine, and low-dose radiotherapy. Thirty-nine patients were included (24 men; 15 women). The median age was 60 years (range 30-76) and median Karnofsky performance status (KPS) score was 70 (range 50-100). There was substantial inter-individual variability in MTX AUC (median: 795.5 µM*h/L, range 44.8-8326.44). However, there were no differences in progression-free survival (PFS) in patients below and above the median MTX AUC (2-year PFS 78% vs. 85% respectively; p = 0.51). Similarly, there were no differences in response rates or overall survival according to MTX AUC, suggesting that intra-patient dose escalation to increase MTX exposure is unnecessary when our regimen is utilized.

Primary central nervous system lymphomas: a validation study of array-based comparative genomic hybridization in formalin-fixed paraffin-embedded tumor specimens

PURPOSE

Only a limited number of genetic studies have been conducted in primary central nervous system lymphomas (PCNSL), partly due to the rarity of the tumors and the very limited amount of available tissue. In this report, we present the first molecular characterization of copy number abnormalities (CNA) of newly diagnosed PCNSL by array-based comparative genomic hybridization (aCGH) in formalin-fixed paraffin-embedded (FFPE) specimens and compare the results with matched, frozen tumor specimens.

EXPERIMENTAL DESIGN

We conducted aCGH in FFPE tissues from PCNSL. Results were compared with matched, paired, frozen tumors.

RESULTS

Our analysis confirmed the good to fair quality and reliability of the data generated from limited amounts of tumoral FFPE tissue. Overall, all PCNSL cases were characterized by highly complex karyotypes, with a median of 23 CNAs per patient (range, 17-47). Overall, 20 chromosomal regions were recurrently found in more than 40% of cases. Deletions of 6p21, 6q, and 9p21.3 and gain of 12q12-q24.33 were the commonest CNAs. Other minimal affected regions were defined, and novel recurrent CNAs affecting single genes were identified in 3q26.32 (TBL1XR1) and 8q12.1 (TOX).

CONCLUSIONS

The results obtained are encouraging. Larger archival tissue collections can now be analyzed to complement the still fragmented knowledge we have of the genetic basis of the PCNSL.

Primary CNS lymphoma other than DLBCL: a descriptive analysis of clinical features and treatment outcomes

Diffuse large B-cell lymphoma (DLBCL) constitutes most primary central nervous system (CNS) lymphoma (PCNSL), whereas T-cell, low-grade and Burkitt’s lymphomas (BL) are rarely encountered. Due to the paucity of cases, little is known about the clinical features and treatment outcomes of PCNSL other than DLBCL. The objective of this study was to describe the clinical characteristics and outcomes for patients with PCNSL other than DLBCL. Fifteen patients, newly diagnosed with PCNSLs other than DLBCL between 2000 and 2010, were included. The male to female ratio was 0.67:1 with a median age of diagnosis of 31 years (range 18–59). Pathologic distributions were as follows: peripheral T-cell lymphoma (PTCL; n = 7), marginal zone B-cell lymphoma (MZBCL; n = 1), lymphoplasmacytic lymphoma (LPL; n = 2), Burkitt’s lymphoma (n = 1), other unspecified (T-cell lineage, n = 2; B-cell lineage, n = 2). Thirteen patients (87%) showed Eastern Cooperative Oncology Group performance score (ECOG PS) 1–2. The remaining two were one PTCL patient and one Burkitt’s lymphoma patient. Of the nine patients with T-cell lymphoma, five (56%) had multifocal lesions, and one (20%) with LPL of the five patients with B-cell lymphoma showed a single lesion. Leptomeningeal lymphomatosis was identified in two patients (one with Burkitt’s lymphoma and one with unspecified B-cell lymphoma). Two patients (22%) with T-cell lymphoma died 7.7 and 23.3 months later, respectively, due to disease progression, despite HD-MTX-based therapy. Six patients with T-cell lymphoma (6/9, 66.7%) and four patients with low-grade B-cell lymphoma (4/5, 80%) achieved complete response and have survived without relapse (Table 3). One patient with Burkitt’s lymphoma showed poor clinical features with ECOG PS 3, deep structure, multifocal, and leptomeningeal lymphomatosis, and died 7.6 months after the initiation of treatment. In comparison with previously reported DLBCLs (median OS 6.4 years, 95% CI 3.7–9.1 years), T-cell lymphoma showed equivocal or favorable clinical outcomes and low-grade B-cell lymphomas, such as MZBCL and LPL, had a good prognosis. However, primary CNS Burkitt’s lymphoma presented poor clinical outcomes and showed a comparatively aggressive clinical course. In conclusion, primary CNS lymphoma other than DLBCL occurred more in younger patients and showed a generally good prognosis, except for Burkitt’s lymphoma. Further research on treatment strategies for Burkitt’s lymphoma is needed.

YKL-40 and MMP-9 as serum markers for patients with primary central nervous system lymphoma

OBJECTIVE

To evaluate YKL-40 and MMP-9 proteins as tumor biomarkers in serum samples from patients with primary central nervous system lymphoma (PCNSL).

METHODS

In this prospective longitudinal study, serum samples from consecutive patients with histologically confirmed PCNSL were collected concurrently with magnetic resonance imaging (MRI) scans at multiple time points and were analyzed for levels of YKL-40 and MMP-9 by enzyme-linked immunosorbent assay. Marker levels were correlated to disease status and survival.

RESULTS

Forty-five patients with PCNSL were accrued. Median follow-up for survivors was 25 months, and 21 (47%) died during the study. A total of 230 serum samples were collected, and 93% had corresponding MRI scans. PCNSL patients without evidence of radiographic disease (29 patients, 131 samples) had significantly lower levels of serum YKL-40 and MMP-9 than patients with active tumor (n = 34 patients, 84 samples; p = 0.03 and 0.01, respectively). There was a significant inverse correlation between survival and doubling of the YKL-40 level (hazard ratio, 1.7; p = 0.01).

INTERPRETATION

In patients with PCNSL, serum levels of YKL-40 and MMP-9 are associated with radiographic disease status. Longitudinal increase in serum levels of YKL-40, but not MMP-9, predicts survival in patients with PCNSL.

Clinical importance of Bcl-6-positive non-deep-site involvement in non-HIV-related primary central nervous system diffuse large B-cell lymphoma

In several studies of primary central nervous system lymphoma (PCNSL), deep-site involvement of the brain, as well as age and performance status (PS), were found to be independent prognostic factors. In immunocompetent patients, most primary central nervous system lymphomas (PCNSL) are diffuse large B-cell lymphomas (DLBCL), and recent studies have shown that Bcl-6 would be a favorable prognostic biomarker in PCNS-DLBCL. The objective of this study is to evaluate the clinical importance of the central nervous system (CNS) involvement pattern combined with Bcl-6 expression in PCNS-DLBCL patients. This study included 65 immunocompetent patients with PCNS-DLBCL who underwent treatment with high-dose methotrexate with whole-brain radiotherapy. Immunochemistry was performed for the Bcl-6 and Ki-67 antigens. Forty-four patients were male and 21 patients were female, with median age of 59 years. During the median follow-up period of 26 months, progression-free survival (PFS) was 25% and overall survival (OS) was 31%. Of 65 cases that could be subclassified, 31 patients were Bcl-6 positive and 34 patients were negative. Deep-site involvement of the brain was observed in 31 patients. The Bcl-6-positive group and the group having non-deep-site involvement of the brain were associated with favorable progression-free survival (PFS) (P < 0.001; P < 0.001) and overall survival (OS) (P = 0.001; P < 0.001). Results of univariate analysis showed that age above 60 years, Eastern Cooperative Oncology Group (ECOG) PS above 2, elevated lactate dehydrogenase (LDH) state, complete response (CR), and Bcl-6-positive and deep-site involvement were prognostic factors associated with PFS and OS. Results of multivariate analysis revealed that age above 60 years, ECOG above 2, elevated LDH state, Bcl-6 positivity, and deep-site involvement were independent prognostic factors for prediction of outcome. According to the combined prognostic value of Bcl-6 expression and the deep-site involvement pattern, the subgroup having Bcl-6-positive non-deep-site involvement of the brain showed more favorable PFS and OS than the other subgroups (P < 0.001, P < 0.001), whereas differences of survival among the other three subgroups were not significant (P = 0.054, P = 0.056). Bcl-6 positivity was found to be an independent prognostic factor for survival. Bcl-6 expression was associated with higher PFS and OS in patients having non-deep-site involvement. However, this was counteracted in the group of patients having deep-site involvement of the brain.

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.

Immunochemotherapy with rituximab, methotrexate, procarbazine, and lomustine for primary CNS lymphoma (PCNSL) in the elderly

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is an aggressive extranodal non-Hodgkin lymphoma confined to the central nervous system. In this article, we report the results of a pilot trial adding rituximab to the established regimen consisting of methotrexate, procarbazine, and lomustine (R-MCP).

DESIGN AND METHODS

PCNSL patients ≥65 years without Karnofsky performance score (KPS) limit were included. R-MCP regimen consisted of rituximab (375 mg/m(2) i.v. on days -6, 1, 15, and 29), methotrexate (3 g/m(2) i.v., days 2, 16, and 30) followed by folinic rescue, procarbazine (60 mg/m(2) orally, days 2-11), and lomustine (110 mg/m(2) orally, day 2). A maximum of three 43-day cycles were applied. Primary end point was response to treatment obtained by magnetic resonance imaging. Secondary end points were overall survival (OS) and progression-free survival (PFS).

RESULTS

Twenty-eight patients were included (median age 75, median KPS 60%). Best documented response: complete remission in 18 of 28 (64%), partial remission in 5 of 28 (18%), stable disease in 1 of 28 (4%), and progressive disease in 2 of 28 (7%) patients. Response was not assessed in two patients. Two treatment-associated deaths were observed. After a median follow-up of 36 months, the 3-year PFS and OS was 31%.

CONCLUSION

R-MCP regimen is well tolerated and active in elderly patients with newly diagnosed PCNSL.

Influence of methotrexate exposure on outcome in patients treated with MBVP chemotherapy for primary central nervous system lymphoma

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Although treated using the same high-dose methotrexate (HD-MTX)-based multiagent chemotherapy, patients with primary central nervous system lymphoma (PCNSL) have significant differences in outcome. However, little information has been published about factors influencing outcome in PCNSL. As it is known that the pharmacokinetics of MTX vary considerably between subjects leading to different exposure in patients receiving the same dose, it is important to evaluate its role in response to chemotherapy.

WHAT THIS STUDY ADDS

This study is the first to evaluate the exposure-response relationship in patients treated with MBVP chemotherapy. We found that patients who were early non-responders to MBVP chemotherapy had poor survival, whatever the salvage regimen. Tumour response at early evaluation was not associated with MTX pharmacokinetics and increasing the dose would probably not improve results.

AIMS

Although the standard treatment for primary central nervous system lymphoma (PCNSL) consists of three cycles of MBVP (methotrexate, BCNU, VP16, methylprednisolone) and radiotherapy, early failure of treatment may require modification of the treatment. However, our understanding of the outcome in such patients and of the factors involved in early failure of treatment is poor. In addition to known prognostic factors, we evaluated the influence of methotrexate (MTX) exposure on the response to MBVP chemotherapy in patients treated for PCNSL after the first two cycles.

METHODS

We retrospectively analyzed all patients with PCNSL treated with the MBVP regimen over the previous 10 years. Clinical, personal data and known prognostic factors were studied. The parameters of MTX exposure were estimated using a population pharmacokinetic approach with NONMEM. Objective response (OR), overall survival (OS) and failure-free survival (FFS) were evaluated in all patients.

RESULTS

Thirty-seven patients were studied. We observed lower FFS and OS (0.49 years) in patients who were not able to receive the planned treatment (group 1, n=12) than in those who received three cycles (8.04 years) (group 2, n=25). Known prognostic factors were comparable in both groups, but mean dose of MTX and mean AUC tended to be lower in patients who failed prematurely or showed no response after two cycles.

CONCLUSIONS

We found that patients who were early non-responders to MBVP chemotherapy had poor survival, without major influence of MTX exposure. It is thus probably unlikely that increasing the dose of MTX would improve outcome.

Primary central nervous system lymphoma

PURPOSE OF REVIEW

This review will summarize recent advances in the understanding and treatment of primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

The molecular and genetic characteristics that distinguish PCNSL are beginning to be elucidated. New tools such as flow cytometry and PET are improving the diagnosis and management of PCNSL. Although the current standard of care is high-dose methotrexate-based chemotherapy alone or in combination with whole brain radiotherapy, multiple questions remain regarding the optimal treatment of PCNSL, in general, and unusual variants of PCNSL.

SUMMARY

Although recent advances have improved our understanding of PCNSL, the need for additional collaborative research is critical.

Primary intramedullary histiocytic sarcoma

Intramedullary primary central nervous system lymphoma (PCNSL) is a rare central nervous system (CNS) malignancy affecting mostly the brain, but it may also involve the leptomeninges, eyes, and spinal cord. A 71-year-old woman presented with back pain and progressive unilateral lower extremity weakness owing to an intramedullary primary histiocytic sarcoma of the spine, a rare PCNSL subtype. To the authors' knowledge, this is the first case of an intramedullary PCNSL caused by histiocytic sarcoma.

Primary CNS lymphoma in children and adolescents: a descriptive analysis from the International Primary CNS Lymphoma Collaborative Group (IPCG)

PURPOSE

To describe the demographic and clinical features and outcomes for children and adolescents with primary CNS lymphoma (PCNSL).

EXPERIMENTAL DESIGN

A retrospective series of children and adolescents with PCNSL was assembled from 10 cancer centers in 3 countries.

RESULTS

Twenty-nine patients with a median age of 14 years were identified. Sixteen (55%) had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 1 or greater. Frontline therapy consisted of chemotherapy only in 20 patients (69%), while 9 (31%) had chemotherapy plus cranial radiotherapy. Most patients received methotrexate (MTX)-based regimens. Overall response rate was 86% (complete remission 69%, partial remission 17%). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 61% and 86%, respectively; the 3-year OS was 82%. Univariate analyses were conducted for age (≤ 14 vs. >14 years), PS (0 or 1 vs. >1), deep brain lesions, MTX dose, primary treatment with chemotherapy alone, intrathecal chemotherapy, and high-dose therapy. Primary treatment with chemotherapy alone was associated with better overall response rates with an odds ratio (OR) of 0.125 (P = 0.02). There was a marginally significant relationship between higher doses of MTX and response (OR = 1.5, P = 0.06). ECOG-PS of 0 to 1 was the only factor associated with better outcome with hazard ratios of 0.136 (P = 0.017) and 0.073 (P = 0.033) for PFS and OS, respectively.

CONCLUSION

This is the largest series collected of pediatric PCNSL. The outcome of children and adolescents seems to be better than in adults. PS of 0 to 1 is associated with better survival.

Primary central nervous system lymphoma: a clinicopathological study of 75 cases

AIMS

Pathological and clinical data in a large series of immunocompetent patients with primary lymphoma of the central nervous system (PCNSL) were analysed.

METHODS

We immunostained tumour specimens of 75 patients for CD3, CD4, CD5, CD8, CD10, CD20, CD30, CD79a, Bcl-2, Bcl-6, CD138, MUM1, TDT, PAX5, FOXP1 and Ki-67 and performed in situ hybridisation for Epstein-Barr virus (EBV) RNA. Eleven cases were investigated for rearrangements of BCL6, immunoglobulin heavy chain (IGH) and FOXP1 genes using fluorescent in situ hybridisation (FISH).

RESULTS

Histologically, most cases were classified as diffuse large B-cell lymphoma (80.2%) predominantly of centroblastic type. Immunophenotypic profiling revealed that 96% and 4% of cases corresponded to non-germinal centre and germinal centre type, respectively. FISH analysis showed t(3;14)/IGH-BCL6 in 2/11 cases and trisomy 3 in 2/11 cases. FOXP1 rearrangements were not found. At survival analysis, Karnofsky index >80 and presence of Bcl-6 expression showed independent significant association with favourable patient outcome.

CONCLUSIONS

PCNSL represents a histologically and immunophenotypically very homogeneous lymphoma type, probably derived from germinal centre exit B cells. The frequent overexpression of FOXP1 appears not to be related to FOXP1 gene rearrangement. Survival analyses disclosed Bcl-6 expression and high Karnofsky performance score as independent prognostic parameters associated with favourable outcome.

Characteristics and outcomes of elderly patients with primary central nervous system lymphoma: the Memorial Sloan-Kettering Cancer Center experience

BACKGROUND

Approximately 50% of all patients with primary central nervous system lymphoma (PCNSL) are aged ≥65 years; however, this group is relatively understudied, and to the authors's knowledge, optimal treatment for older patients is not well defined.

METHODS

This was a retrospective review of PCNSL patients aged ≥65 years who were treated at Memorial Sloan-Kettering Cancer Center between 1986 and 2008. A multivariate analysis of demographic and clinical variables on prognosis and receipt of treatment was performed.

RESULTS

One hundred seventy-four patients between the ages of 65 and 89 years were identified; there was a slight predominance of women (52.9%). One hundred forty-eight patients were treated with chemotherapy at the time of diagnosis (98% with methotrexate-based therapy) and 31 of these patients also received whole-brain radiotherapy (WBRT). Sixteen patients received WBRT alone. A radiographic response to chemotherapy was noted in 76% of patients. Ninety patients developed disease progression after initial treatment; 74 received salvage therapy and 48% of these patients responded to salvage treatment. The median overall survival was 25 months (range, 18-33 months), and the 3-year survival rate was 36%. Approximately 20.1% of patients were alive for ≥11 years. WBRT was delivered more frequently before 1998, and patients with a history of prior malignancy were less likely to receive WBRT. Age and performance status were identified as the most important predictors of survival. Treatment-related neurotoxicity at 2 years was strongly associated with receipt of WBRT (P=.0002).

CONCLUSIONS

PCNSL in the elderly remains sensitive to methotrexate-based chemotherapy and aggressive treatment may be warranted both at the time of diagnosis and disease recurrence.

High-dose methotrexate with or without whole brain radiotherapy for primary CNS lymphoma (G-PCNSL-SG-1): a phase 3, randomised, non-inferiority trial

BACKGROUND

High-dose methotrexate is the standard of care for patients with newly diagnosed primary CNS lymphoma. The role of whole brain radiotherapy is controversial because delayed neurotoxicity limits its acceptance as a standard of care. We aimed to investigate whether first-line chemotherapy based on high-dose methotrexate was non-inferior to the same chemotherapy regimen followed by whole brain radiotherapy for overall survival.

METHODS

Immunocompetent patients with newly diagnosed primary CNS lymphoma were enrolled from 75 centres and treated between May, 2000, and May, 2009. Patients were allocated by computer-generated block randomisation to receive first-line chemotherapy based on high-dose methotrexate with or without subsequent whole brain radiotherapy, with stratification by age (<60 vs ≥60 years) and institution (Berlin vs Tübingen vs all other sites). The biostatistics centre assigned patients to treatment groups and informed local centres by fax; physicians and patients were not masked to treatment group after assignment. Patients enrolled between May, 2000, and August, 2006, received high-dose methotrexate (4 g/m(2)) on day 1 of six 14-day cycles; thereafter, patients received high-dose methotrexate plus ifosfamide (1·5 g/m(2)) on days 3-5 of six 14-day cycles. In those assigned to receive first-line chemotherapy followed by radiotherapy, whole brain radiotherapy was given to a total dose of 45 Gy, in 30 fractions of 1·5 Gy given daily on weekdays. Patients allocated to first-line chemotherapy without whole brain radiotherapy who had not achieved complete response were given high-dose cytarabine. The primary endpoint was overall survival, and analysis was per protocol. Our hypothesis was that the omission of whole brain radiotherapy does not compromise overall survival, with a non-inferiority margin of 0·9. This trial is registered with ClinicalTrials.gov, number NCT00153530.

FINDINGS

551 patients (median age 63 years, IQR 55-69) were enrolled and randomised, of whom 318 were treated per protocol. In the per-protocol population, median overall survival was 32·4 months (95% CI 25·8-39·0) in patients receiving whole brain radiotherapy (n=154), and 37·1 months (27·5-46·7) in those not receiving whole brain radiotherapy (n=164), hazard ratio 1·06 (95% CI 0·80-1·40; p=0·71). Thus our primary hypothesis was not proven. Median progression-free survival was 18·3 months (95% CI 11·6-25·0) in patients receiving whole brain radiotherapy, and 11·9 months (7·3-16·5; p=0·14) in those not receiving whole brain radiotherapy. Treatment-related neurotoxicity in patients with sustained complete response was more common in patients receiving whole brain radiotherapy (22/45, 49% by clinical assessment; 35/49, 71% by neuroradiology) than in those who did not (9/34, 26%; 16/35, 46%).

INTERPRETATION

No significant difference in overall survival was recorded when whole brain radiotherapy was omitted from first-line chemotherapy in patients with newly diagnosed primary CNS lymphoma, but our primary hypothesis was not proven. The progression-free survival benefit afforded by whole brain radiotherapy has to be weighed against the increased risk of neurotoxicity in long-term survivors.

Primary central nervous system lymphoma in the elderly: a multicentre retrospective analysis

Elderly patients with primary central nervous ystem lymphoma (PCNSL) do not tolerate treatment with combined radio-chemotherapy well because of leuco-encephalopathy; they are usually treated initially with chemotherapy or radiotherapy alone. Little is known about the efficacy and toxicity of these treatments outside clinical studies. This study was a retrospective analysis of all patients aged 60 years or over who were admitted with PCNSL to one of five Dutch centers between 1998 and 2007. A total of 74 patients were identified. Twenty-nine were treated with radiotherapy only (Group A), in 36 the intended treatment was chemotherapy alone (Group B), and nine were planned to receive chemotherapy followed by radiotherapy (Group C). Median overall survival was 20 months; 4 months in patients with a Karnofsky performance status (KPS) <70, 25 months in patients with a KPS ≥ 70 (P < 0·001). Treatment modality was not an independent prognostic factor. Forty patients were treated with methotrexate 3 g/m(2) : there were two toxic deaths. Ten patients discontinued chemotherapy because of toxicity. Delayed encephalopathy was reported in 10 patients. In conclusion, community hospitals still frequently utilize whole brain radiotherapy in elderly PCNSL patients, though a majority tolerates chemotherapy well. Performance status was the most important variable determining prognosis. Short and long term toxicities must be weighed against possible clinical benefits of each treatment, making treatment decisions a highly individualized process.