Primary central nervous system non-Hodgkin's lymphoma (PCNSL): survival advantages with combined initial therapy? A final report of the North Central Cancer Treatment Group (NCCTG) Study 86-72-52

Advances in Primary Central Nervous System Lymphoma

PURPOSE OF REVIEW

Optimal initial management can have a significant impact in long-term outcome in primary CNS lymphoma. This article reviews recent advances and the state of the field.

RECENT FINDINGS

Genomic analysis of CSF cell-free DNA has emerged as a new diagnostic tool for PCNSL. Treatment options have likewise evolved, with mature data from first-line chemotherapy-based prospective trials disclosing excellent results in younger (< 60-65) patients, with a cure achieved in a majority. However, results in older patients remain dismal, with several new salvage options under investigation including BTK pathway-targeted therapies, and CAR-T cell treatments. Meanwhile, low-dose radiation has emerged as an additional alternative for consolidation therapy. For younger PCNSL patients, the goal of treatment is now a cure, with the next frontier being the development of therapies affording optimized neurocognitive outcome and lower toxicity. Treatment for older patients remains however an unmet need, with several promising clinical trials ongoing.

ACT001 inhibits primary central nervous system lymphoma tumor growth by enhancing the anti-tumor effect of T cells

Primary central nervous system lymphoma (PCNSL) is a group of malignant brain tumors with a poor prognosis, and new therapeutic approaches for this tumor urgently need to be investigated. Formulated from a long-standing anti-inflammatory drugs, ACT001 has demonstrated in clinical research to be able to pass through the blood-brain barrier (BBB) and affect the central nervous system. The effects of ACT001 on PCNSL cell apoptosis, proliferation and immune-related indexes were detected by flow cytometry, and the efficacy of ACT001 was verified in vivo by constructing a mouse PCNSL tumor model. ACT001 significantly inhibited PCNSL cell proliferation and induced apoptosis in vitro. In addition, ACT001 can significantly inhibit the PD-1/PD-L1 expression and restore the function of T cells, so that the immune system cannot allow tumor cells to escape. In vivo experiments show that co-infusion of ACT001 and T cells effectively inhibits PCNSL tumor growth in NSG mice. Our work describes the inhibitory effect of ACT001 on the PCNSL cell line and demonstrated the inhibitory effect of ACT001 on immune checkpoints.

Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphomatous malignancy that affects the brain, spinal cord, leptomeninges, or vitreoretinal space, without evidence of systemic involvement. The diagnosis of PCNSL requires a high level of suspicion because clinical presentation varies depending upon involved structures. Initiation of treatment is time sensitive for optimal neurologic recovery and disease control. In general, the prognosis of PCNSL has improved significantly over the past few decades, largely as a result of the introduction and widespread use of high-dose methotrexate (MTX) chemotherapy, which is considered the backbone of first-line polychemotherapy treatment. Upon completion of MTX-based treatment, a consolidation strategy is often required to prolong duration of response. Consolidation can consist of radiation, maintenance therapy, nonmyeloablative chemotherapy, or myeloablative treatment followed by autologous stem cell transplant. Unfortunately, even with consolidation, relapse is common, and 5-year survival rates stand at only 30% to 40%. Novel insights into the pathophysiology of PCNSL have identified key mechanisms in tumor pathogenesis, including activation of the B-cell receptor pathway, immune evasion, and a suppressed tumor immune microenvironment. These insights have led to the identification of novel small molecules targeting these aberrant pathways. The Bruton tyrosine kinase inhibitor ibrutinib and immunomodulatory drugs (lenalidomide or pomalidomide) have shown promising clinical response rates for relapsed/refractory PCNSL and are increasingly used for the treatment of recurrent disease. This review provides a discussion of the clinical presentation of PCNSL, the approach to work-up and staging, and an overview of recent advancements in the understanding of the pathophysiology and current treatment strategies for immunocompetent patients.

High-dose methotrexate and rituximab induction regimen in immunocompetent patients with primary CNS lymphoma: a retrospective single-center study of survival predictors

PURPOSE

Primary Central Nervous System Lymphoma (PCNSL) is an aggressive tumor that is confined to the CNS. Although the provision of high-dose methotrexate (HD-MTX) has remarkably improved outcomes in PCNSL patients, the optimal treatment regimens and standard MTX dose for induction therapy have been largely controversial. Herein, we sought to explore the impact of adjuvant rituximab and different dosages of induction HD-MTX on survival outcomes of immunocompetent patients with PCNSL.

METHODS

In this study, we examined patients with PCNSL treated at a single NCI-designated comprehensive cancer center to evaluate their survival outcomes. We conducted a retrospective analysis of 51 immunocompetent patients with PCNSL who received their induction chemotherapy at the University of Alabama at Birmingham (UAB) between 2001 and 2019. Only adult patients with a confirmed diagnosis of PCNSL who had either HD-MTX alone or in combination with rituximab were included. Patients' demographics, clinical characteristics, and survival data were collected and analyzed.

RESULTS

There is no significant difference in survival among patients who received MTX alone versus MTX plus rituximab (HR = 0.996 (95% CI: 0.398-2.493), p = 0.994). Lower doses of MTX were associated with worse survival outcomes (HR = 0.680 (95% CI: 0.530-0.872), p = 0.002); however, this difference in survival was not significant when adjusted to age (HR = 0.797 (95% CI: 0.584-1.088), p = 0.153).

CONCLUSION

Our experience challenges the role of rituximab in PCNSL during induction therapy. Our study also highlights the shorter survival in elderly patients with PCNSL which can be related, to some extent, to the relatively lower doses of HD-MTX. There is an unmet need to establish a consensus on the most effective upfront regimen in PCNSL through prospective studies.

Treatment Regimens for Immunocompetent Elderly Patients with Primary Central Nervous System Lymphoma: A Scoping Review

BACKGROUND

Most patients diagnosed with primary central nervous system lymphoma (PCNSL) are older than 60 years. Despite promising treatment options for younger patients, prognosis for the elderly remains poor and efficacy of available treatment options is limited.

MATERIALS AND METHODS

We conducted a scoping review to identify and summarize the current study pool available evaluating different types and combinations of (immuno) chemotherapy with a special focus on HCT-ASCT in elderly PCNSL. Relevant studies were identified through systematic searches in the bibliographic databases Medline, Web of Science, Cochrane Library and ScienceDirect (last search conducted in September 2020). For ongoing studies, we searched ClinicalTrials.gov, the German study register and the WHO registry.

RESULTS

In total, we identified six randomized controlled trials (RCT) with 1.346 patients, 26 prospective (with 1.366 patients) and 24 retrospective studies (with 2.629 patients). Of these, only six studies (one completed and one ongoing RCT (with 447 patients), one completed and one ongoing prospective single arm study (with 65 patients), and two retrospective single arm studies (with 122 patients)) evaluated HCT-ASCT. Patient relevant outcomes such as progression-free and overall survival and (neuro-)toxicity were adequately considered across almost all studies. The current study pool is, however, not conclusive in terms of the most effective treatment options for elderly. Main limitations were (very) small sample sizes and heterogeneous patient populations in terms of age ranges (particularly in RCTs) limiting the applicability of the results to the target population (elderly).

CONCLUSIONS

Although it has been shown that HCT-ASCT is probably a feasible and effective treatment option, this approach has never been investigated within a RCT including a wide range of elderly patients. A RCT comparing conventional (immuno) chemotherapy with HCT-ASCT is crucial to evaluate benefit and harms in an un-biased manner to eventually provide older PCNSL patients with the most effective treatment.

Improving the antitumor activity of R-CHOP with NGR-hTNF in primary CNS lymphoma: final results of a phase 2 trial

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment of diffuse large B-cell lymphoma (DLBCL). Primary DLBCL of the central nervous system (CNS) (primary central nervous system lymphoma [PCNSL]) is an exception because of the low CNS bioavailability of related drugs. NGR-human tumor necrosis factor (NGR-hTNF) targets CD13+ vessels, enhances vascular permeability and CNS access of anticancer drugs, and provides the rationale for the treatment of PCNSL with R-CHOP. Herein, we report activity and safety of R-CHOP preceded by NGR-hTNF in patients with PCNSL relapsed/refractory to high-dose methotrexate-based chemotherapy enrolled in a phase 2 trial. Overall response rate (ORR) was the primary endpoint. A sample size of 28 patients was considered necessary to demonstrate improvement from 30% to 50% ORR. NGR-hTNF/R-CHOP would be declared active if ≥12 responses were recorded. Treatment was well tolerated; there were no cases of unexpected toxicities, dose reductions or interruptions. NGR-hTNF/R-CHOP was active, with confirmed tumor response in 21 patients (75%; 95% confidence interval, 59%-91%), which was complete in 11. Seventeen of the 21 patients with response to treatment received consolidation (ASCT, WBRT, and/or lenalidomide maintenance). At a median follow-up of 21 (range, 14-31) months, 5 patients remained relapse-free and 6 were alive. The activity of NGR-hTNF/R-CHOP is in line with the expression of CD13 in both pericytes and endothelial cells of tumor vessels. High plasma levels of chromogranin A, an NGR-hTNF inhibitor, were associated with proton pump inhibitor use and a lower remission rate, suggesting that these drugs should be avoided during TNF-based therapy. Further research on this innovative approach to CNS lymphomas is warranted. The trial was registered as EudraCT: 2014-001532-11.

Central Nervous System Lymphoma: Approach to Diagnosis and Treatment

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

High-dose methotrexate-based regimens and post-remission consolidation for treatment of newly diagnosed primary CNS lymphoma: meta-analysis of clinical trials

With the exception of high-dose methotrexate (HD-MTX), there is currently no defined standard treatment for newly diagnosed primary central nervous system lymphoma (PCNSL). This review focused on first-line induction and consolidation treatment of PCNSL and aimed to determine the optimal combination of HD-MTX and the long-term beneficial consolidation methods. A comprehensive literature search of MEDLINE identified 1407 studies, among which 31 studies met the inclusion criteria. The meta-analysis was performed by using Stata SE version 15. Forest plots were generated to report combined outcomes like the complete response rate (CRR), overall survival, and progression-free survival. We also conducted univariate regression analyses of the baseline characteristics to identify the source of heterogeneity. Pooled analysis showed a CRR of 41% across all HD-MTX-based regimens, and three- and four-drug regimens had better CRRs than HD-MTX monotherapy. In all combinations based on HD-MTX, the HD-MTX + procarbazine + vincristine (MPV) regimen showed pooled CRRs of 63% and 58% with and without rituximab, respectively, followed by the rituximab + HD-MTX + temozolomide regimen, which showed a pooled CRR of 60%. Pooled PFS and OS showed that post-remission consolidation with autologous stem cell transplantation (ASCT) was associated with the best survival outcome, with a pooled 2-year OS of 80%, a 2-year PFS of 74%, a 5-year OS of 77%, and a 5-year PFS of 63%. Next, whole-brain radiation therapy (WBRT) + chemotherapy showed a pooled 2-year OS of 72%, 2-year PFS of 56%, 5-year OS of 55%, and 5-year PFS of 41%, with no detectable CR heterogeneity throughout the entire treatment process. In HD-MTX-based therapy of newly diagnosed PCNSL, MPV with or without rituximab can be chosen as the inductive regimen, and the rituximab + HD-MTX + temozolomide regimen is also a practical choice. Based on our study, high-dose chemotherapy supported by ASCT is an efficacious approach for consolidation. Consolidation with WBRT + chemotherapy can be another feasible approach.

R-CHOP preceded by blood-brain barrier permeabilization with engineered tumor necrosis factor-α in primary CNS lymphoma

Patients with primary central nervous system lymphoma (PCNSL) are treated with high-dose methotrexate-based chemotherapy, which requires hospitalization and extensive expertise to manage related toxicity. The use of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) could overcome these difficulties, but blood-brain barrier (BBB) penetration of related drugs is poor. Tumor necrosis factor-α coupled with NGR (NGR-hTNF), a peptide targeting CD13⁺ vessels, induces endothelial permeabilization and improves tumor access of cytostatics. We tested the hypothesis that NGR-hTNF can break the BBB, thereby improving penetration and activity of R-CHOP in patients with relapsed/refractory PCNSL (NCT03536039). Patients received six R-CHOP21 courses, alone at the first course and preceded by NGR-hTNF (0.8 μg/m²) afterward. This trial included 2 phases: an "explorative phase" addressing the effect of NGR-hTNF on drug pharmacokinetic parameters and on vessel permeability, assessed by dynamic contrast-enhanced magnetic resonance imaging and ^99mTc-diethylene-triamine-pentacetic acid-single-photon emission computed tomography, and the expression of CD13 on tumor tissue; and an "expansion phase" with overall response rate as the primary end point, in which the 2-stage Simon Minimax design was used. At the first stage, if ≥4 responses were observed among 12 patients, the study accrual would have continued (sample size, 28). Herein, we report results of the explorative phase and the first-stage analysis (n = 12). CD13 was expressed in tumor vessels of all cases. NGR-hTNF selectively increased vascular permeability in tumoral/peritumoral areas, without interfering with drug plasma/cerebrospinal fluid concentrations. The NGR-hTNF/R-CHOP combination was well tolerated: there were only 2 serious adverse events, and grade 4 toxicity was almost exclusively hematological, which were resolved without dose reductions or interruptions. NGR-hTNF/R-CHOP was active, with 9 confirmed responses (75%; 95% confidence interval, 51-99), 8 of which were complete. In conclusion, NGR-hTNF/R-CHOP was safe in these heavily pretreated patients. NGR-hTNF enhanced vascular permeability specifically in tumoral/peritumoral areas, which resulted in fast and sustained responses.

Management of primary central nervous system lymphoma

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

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

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

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.

Updates on Primary Central Nervous System Lymphoma

PURPOSE OF REVIEW

Primary central nervous system lymphoma (PCNSL) is an aggressive malignancy confined to the brain, spinal cord, leptomeninges, and eyes. Due to its rarity, there is a paucity of randomized trials and a varied approach to its management in the oncologic community. This review summarizes recent literature guiding current clinical practice.

RECENT FINDINGS

The presentation, work up, and management of PCNSL are discussed. Induction therapy incorporates a methotrexate-based chemotherapy regimen and is generally followed by a consolidation regimen including high dose chemotherapy (with or without autologous stem cell rescue). Whole brain radiation therapy (WBRT) is a potential additional consolidation strategy. Management of relapsed and refractory disease poses a special challenge due to poor outcomes. Immunotherapy and targeted treatments are promising novel strategies for recurrent/refractory patients. Currently, there is little consensus in the management of PCNSL. Treatment recommendations should be tailored to the individual patient, with consideration for risk of neurotoxicity. New, exciting strategies are in development and when feasible, enrollment in a clinical trial should be considered.

A Regional Multicenter Retrospective Analysis of Patients with Primary Central Nervous System Lymphoma Diagnosed from 2000-2012: Treatment Patterns and Clinical Outcomes

Introduction

Primary central nervous system lymphoma (PCNSL) is a rare tumor without a well-defined standard of care. For immunocompetent patients, therapeutic regimens have largely evolved from treatment with whole-brain radiation therapy (WBRT) to treating initially with systemic chemotherapy regimens that include high-dose (HD) methotrexate (MTX) with or without WBRT. Looking at population-based treatment trends may help define which therapies are most effective. This study was conducted to determine treatment patterns and outcomes for patients with PCNSL in the Louisville, KY metropolitan area during the period 2000 to 2012.

Methods

Data were collected by retrospective chart reviews of patients identified using the International Classification of Diseases (ICD) code from three major oncology practices in the Louisville metropolitan area during the period 2000 to 2012. Patients were excluded if they were under age 18, positive for human immunodeficiency virus (HIV), had histology other than B-cell lymphoma, or had systemic lymphoma.

Results

A total of 21 patients were identified. The median age was 65 years (range: 30 to 90). All patients were Caucasian, and the median Karnofsky performance status (KPS) score was 80 (range: 50 to 100). The ratio of males to females was 1:1.3. Median overall survival (OS) for all patients was 22 months (range: 1 to 155 months). Of 21 patients, 11 (52 percent) received chemotherapy regimens that included systemic HD-MTX at their initial diagnosis with a median OS of 22 months (range: 1 to 155 months). Nine of 21 patients (42 patients) were offered other therapies, including WBRT or non-MTX-based chemotherapies; they had a median OS of 5 months (range: 2 to 150 months). The median OS for patients receiving at least four cycles of HD-MTX was 40 months (range: 4 to 155 months).

Conclusions

This population-based study shows that patients with PCNSL and the ability to undergo HD-MTX-based therapy had a superior survival rate compared to those receiving radiation alone or other non-HD-MTX-based therapies. 

Primary CNS Lymphoma

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

[Primary central nervous lymphoma: what is the role for radiotherapy?]

Primary central nervous system lymphoma is a rare extranodal form of non-Hodgkin lymphoma with an aggressive course and unsatisfactory outcome. Historically, whole-brain radiotherapy was the sole treatment for patients with primary central nervous system lymphoma, with high response rates but typically, this did not result in long-lasting remissions. The addition of high-dose methotrexate-based chemotherapy regimens to whole-brain radiotherapy has significantly improved patients' outcome, but has resulted in a higher incidence of late neurotoxicity, particularly in elderly patients. To date, the role of consolidation radiotherapy is controversial, and some investigators have developed alternative strategies aiming at avoiding immediate irradiation or using a reduced radiotherapy dose to the whole-brain with promising results.

Analysis of radiotherapy in 1054 patients with primary central nervous system lymphoma treated from 1985 to 2009

AIMS

Data on primary central nervous system lymphoma that had been collected through surveys for four consecutive periods between 1985 and 2009 were analysed to evaluate outcomes according to treatment.

MATERIALS AND METHODS

All had histologically proven disease and had received radiotherapy. No patients had AIDS. Among 1054 patients, 696 died and 358 were alive or lost to follow-up. The median follow-up period for surviving patients was 37 months.

RESULTS

For all patients, the median survival time was 24 months; the 5 year survival rate was 25.8%. Patients treated with methotrexate-based chemotherapy and radiation had a higher 5 year survival rate (43%) than those treated with radiation alone (14%) and those treated with non-methotrexate chemotherapy plus radiation (20%), but differences in relapse-free survival were smaller among the three groups. The 5 year survival rate was 25% for patients treated with whole-brain irradiation and 29% for patients treated with partial-brain irradiation (P = 0.80). Patients receiving a total dose of 40-49.9 Gy had a higher 5 year survival rate (32%) than those receiving other doses (21-25%, P = 0.0004) and patients receiving a whole-brain dose of 30-39.9 Gy had a higher 5 year survival rate (32%) than those receiving ≥40 Gy (13-22%, P < 0.0005). Patients receiving methotrexate-based chemotherapy and partial-brain radiotherapy (≥30 Gy) had a 5 year survival rate of 49%.

CONCLUSIONS

The optimal total and whole-brain doses may be in the range of 40-49.9 and <40 Gy, respectively, especially in combination with chemotherapy. Patients receiving partial-brain irradiation had a prognosis similar to that of those receiving whole-brain irradiation. With methotrexate-based chemotherapy, partial-brain radiotherapy may be worth considering for non-elderly patients with a single tumour.

Radiation therapy for primary central nervous system lymphoma

Up until the late 1970s, radiation therapy played an important role in the treatment of primary central nervous system lymphoma (PCNSL) but more recently its role has changed due to the increased use of systemic chemotherapy. In this article, the current status of radiotherapy for PCNSL and optimal forms of radiotherapy, including the treatment volume and radiation dose, are discussed. Data from nationwide Japanese surveys of PCNSL patients treated with radiation therapy suggest that the prognosis of PCNSL patients improved during the 1990s, in part due to the use of high-dose methotrexate-containing chemotherapy. The prognosis of patients treated with radiation alone also improved. Radiotherapy still seems to play an important role in the attempt to cure this disease.

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.

CHOD/BVAM chemotherapy and whole-brain radiotherapy for newly diagnosed primary central nervous system lymphoma

PURPOSE

To assess the efficacy and toxicity of chemotherapy consisting of cyclophosphamide, doxorubicin (Adriamycin), vincristine, and dexamethasone (CHOD) plus bis-chloronitrosourea (BCNU), cytosine arabinoside, and methotrexate (BVAM) followed by whole-brain irradiation (WBRT) for patients with primary central nervous system lymphoma (PCNSL).

METHODS AND MATERIALS

Patients 70 years old and younger with newly diagnosed, biopsy-proven PCNSL received one cycle of CHOD followed by two cycles of BVAM. Patients then received WBRT, 30.6 Gy, if a complete response was evoked, or 50.4 Gy if the response was less than complete; both doses were given in 1.8-Gy daily fractions. The primary efficacy endpoint was 1-year survival.

RESULTS

Thirty-six patients (19 men, 17 women) enrolled between 1995 and 2000. Median age was 60.5 years (range, 34 to 69 years). Thirty (83%) patients had baseline Eastern Cooperative Oncology Group performance scores of 0 to 1. All 36 patients were eligible for survival and response evaluations. Median time to progression was 12.3 months, and median survival was 18.5 months. The percentages of patients alive at 1, 2, and 3 years were 64%, 36%, and 33%, respectively. The best response was complete response in 10 patients and immediate progression in 7 patients. Ten (28%) patients had at least one grade 3 or higher neurologic toxicity.

CONCLUSIONS

This regimen did improve the survival of PCNSL patients but also caused substantial toxicity. The improvement in survival is less than that reported with high-dose methotrexate-based therapies.

Efficacy and MRI of rituximab and methotrexate treatment in a nude rat model of CNS lymphoma

To determine the efficacy of methotrexate and/or rituximab in a CNS lymphoma model and to evaluate MRI modalities for monitoring efficacy, we inoculated female athymic nude rats (rnu/rnu) intracerebrally with human MC116 B-lymphoma cells. Between days 16 and 26, rats were randomized to receive intravenous (IV) treatment with (1) saline (controls, n = 15), (2) methotrexate 1,000 mg/m(2) (n = 6), (3) rituximab 375 mg/m(2) (n = 6), or (4) rituximab plus methotrexate (n = 6). T2/fluid-attenuated inversion recovery (FLAIR) and gadolinium contrast-enhanced T1 MRI sequences were performed prior to and 1 week after treatment. IV rituximab gave an objective tumor response in four of six animals (>50% reduction in tumor volume comparing pre- and posttreatment T2/FLAIR MRI) and resulted in stable disease (50%-125% of baseline) in another animal. The percent change in tumor volume on T2/FLAIR images was significantly different in the control versus rituximab group (p = 0.0051). IV methotrexate slowed tumor growth, compared to controls, but only one of six animals had an objective response. In untreated controls, tumor histological volumes correlated well with T2/FLAIR or contrast-enhanced T1 images (r = 0.877). In the treatment groups, T2/FLAIR correlation was good, but the gadolinium-enhanced T1 MRI was not significantly correlated with histology (r = 0.19). The MC116 CNS lymphoma model seems valuable for preclinical testing of efficacy and toxicity of treatment regimens. IV rituximab was highly effective, but methotrexate was only minimally effective. T2/FLAIR was superior to contrast-enhanced T1 for monitoring efficacy.

High-dose methotrexate combined with procarbazine and CCNU for primary CNS lymphoma in the elderly: results of a prospective pilot and phase II study

BACKGROUND

To improve survival of elderly patients with primary central nervous system lymphoma (PCNSL), we conducted a phase II study with high-dose methotrexate (MTX) combined with procarbazine and CCNU. To reduce neurotoxicity, whole-brain irradiation was reserved for patients not responding to chemotherapy.

PATIENTS AND METHODS

High-dose MTX was applied on days 1, 15, and 30, procarbazine on days 1-10, and CCNU on day 1. Study treatment comprised up to three 45-day cycles. There was no lower limit of Karnofsky performance status (KPS).

RESULTS

Thirty patients with PCNSL (n = 29) or primary ocular lymphoma (n = 1) were included (median age 70 years, range 57-79 years). The median initial KPS was 60% (range 30%-90%). Best documented response in 27 assessable patients were 12 of 27 (44.4%) complete remissions, 7 of 27 (25.9%) partial remissions, and 8 of 27 (29.6%) disease progressions. Two patients died of probable treatment-related causes. With a median follow-up of 78 months (range 34-105), the 5-year overall survival is 33%. Eight of 30 patients (26.7%) are currently alive and well, six without signs of leukoencephalopathy.

CONCLUSION

The combination of high-dose MTX with procarbazine and CCNU is feasible and effective and results in a low rate of leukoencephalopathy. Comorbidity and toxicity remain of concern when treating PCNSL in elderly patients.

Primary CNS lymphoma treated with combined intra-arterial ACNU and radiotherapy

OBJECT

To assess whether nimustine (ACNU), a drug that can cross the blood brain barrier, combined with radiotherapy, improved the survival of patients with primary central nervous system lymphoma (PCNSL).

CLINICAL MATERIALS AND METHODS

Between 1995 and 2005, we treated 63 immunocompetent PCNSL patients with combination therapy consisting of intra-arterial ACNU (100 mg/m(2)) and whole brain radiotherapy (36-50 Gy). Their median age was 60 years (range 28-81). The median follow-up was 24 months.

FINDINGS

With this regimen we achieved a complete response rate of 75% (43 of 57 patients). Kaplan-Meier estimates for median progression-free survival and median overall survival were 26 and 39 months, respectively. The 3- and 5-year survival rates were 51% (95% confidence interval [CI], 36-65%) and 32% (95% CI, 17-47%), respectively. By multivariate analysis, age (<60 vs. > or =60 years) was the only statistically significant prognostic factor; the WBRT dose, sex, and number of tumors were not significant prognostic factors in this study. Myelosuppression was the most frequent side effect, 60% of patients experienced grade 3-4 leukopenia. Late neurotoxicity as a result of treatment was observed in 14 of 43 patients (34%) and higher age (>60) was associated with a high risk of neurotoxicity.

CONCLUSION

The intra-arterial administration of ACNU combined with radiation therapy yielded a high response rate at acceptable toxicity levels in younger patients with PCNSL. However, late neurotoxicity was a serious complication in patients above 60 years of age.

Implications of the blood–brain barrier in primary central nervous system lymphoma

✓ The optimal treatment of primary central nervous system lymphoma (PCNSL), a rare form of extranodal non-Hodgkin lymphoma, has yet to be defined. Whole-brain radiation therapy (WBRT) has limited efficacy as a single therapeutic modality and is associated with a high risk of delayed neurotoxicity. Methotrexate-based chemotherapy regimens yield poor drug penetration across the blood–brain barrier (BBB), thus necessitating administration of high doses with the concomitant risk of increased systemic and neurological toxicity. Combined-modality therapy (WBRT plus chemotherapy) can improve response and survival rates, yet it is associated with a high risk of neurotoxicity. The aim of chemotherapy in conjunction with BBB disruption is to maximize drug delivery to the brain and improve the agent's efficacy, while preserving neurocognitive function and minimizing systemic toxicity. Methotrexate-based chemotherapy regimens administered in conjunction with BBB disruption have shown promising results in PCNSL. Animal models of central nervous system lymphoma and drug neurotoxicity offer new possibilities to study the effects of various treatments on PCNSL and normal brain and can also help understand biological and pathophysiological aspects of this disease. Because the intact BBB is even less permeable to antibodies than it is to drugs, preclinical and clinical studies of monoclonal antibody delivery (for example, rituximab and 90Y ibritumomab tiuxetan) to the brain in conjunction with BBB disruption offer a new possibility to make these novel treatments more efficient against PCNSL. Regarding the evaluation of more sensitive and specific diagnostic imaging tools, iron oxide–based contrast agents for magnetic resonance imaging have shown promise for better differentiation of PCNSL from other white matter diseases.

Whole-brain radiotherapy and high-dose methylprednisolone for elderly patients with primary central nervous system lymphoma: Results of North Central Cancer Treatment Group (NCCTG) 96-73-51

PURPOSE

The aim of this study was to evaluate the efficacy, toxicity, and survival of whole-brain radiotherapy-treated (WBRT) and high-dose methylprednisolone (HDMP)-treated in elderly patients with primary central nervous system lymphoma (PCNSL).

METHODS AND MATERIALS

Patients with PCNSL who were 70 years and older received 1 g of methylprednisolone daily for 5 days, 30 days after WBRT. Patients then received 1 g of methylprednisolone every 28 days until progression. The primary endpoint was overall survival (OS) at 6 months. Results were compared with those in patients on the previous North Central Cancer Treatment Group (NCCTG) trial who received pre-WBRT cytoxan, adriamycin, vincristine, prednisone (CHOP) and high-dose cytarabine (CHOP-WBRT). A planned interim analysis was performed. The current regimen would be considered inactive if survival was not improved from patients treated with CHOP-WBRT.

RESULTS

Nineteen patients were accrued between 1998 and 2003. Median age was 76 years. Interim analysis revealed a 6-month survival of 33%, resulting in closure of the trial. Toxicity, OS, and event-free survival (EFS) were similar to those in patients more than 70 years of age who received CHOP-WBRT. The subgroup of patients who received HDMP had longer OS (12.1 vs. 7.0 months, p = 0.76) and EFS (11.7 vs. 4.0 months, p = 0.04) compared with the CHOP-WBRT patients alive 60 days after the start of treatment.

CONCLUSIONS

Patients on-study long enough to receive HDMP had prolongation of OS and EFS compared to patients receiving CHOP-WBRT. Although the numbers of patients are too small for statistical conclusions, the HDMP regimen deserves further study.

Intraocular lymphoma 2000-2005: results of a retrospective multicentre trial

BACKGROUND

The prognosis of intraocular lymphoma (IOL) is poor, and the optimal treatment has yet to be defined. This study assesses the clinical characteristics and outcome of patients with IOL diagnosed and treated in the new millennium.

METHODS

Patient data in this retrospective multicentre study were compiled by standardised questionnaires sent to seven university ophthalmology departments. All cases diagnosed with primary and secondary IOL in the past 5 years not associated with HIV infection were included.

RESULTS

Twenty-two patients, 11 men and women; median age 64 (range 38-83) years, median Karnofsky performance status 90% (range 50-100%), were included. Nineteen patients had primary IOL (PIOL): 13 a newly diagnosed disease and six an ocular relapse of primary central nervous system lymphoma (PCNSL). Three patients had secondary IOL. First-line treatment for IOL included systemic chemotherapy in 13 cases, ocular radiation in six and intraocular chemotherapy in three. Complete remission was achieved in 14/20 evaluable patients, partial remission in five and stable disease in one. All patients treated with ifosfamide (IFO) or trofosfamide (TRO) (n=8) responded. Median progression-free survival (PFS) and overall survival were 10 (range 1+ to 44.5+) and 22.5 (range 1+ to 49+) months, respectively. Patients with newly diagnosed PIOL and ocular relapse of PCNSL had a median PFS of 10 (range 1+ to 44.5+) and 6 (range 2 to 6+) months, respectively. Median PFS was 12 (range 3+ to 22.5+) months after systemic and 5.5 (range 1+ to 44.5+) months after local first-line therapy.

CONCLUSIONS

The prognosis of PIOL is similar to that of PCNSL without ocular involvement. Systemic therapy possibly prolongs PFS as compared with local management of (P)IOL. The high response rate to monotherapy with IFO and TRO is promising.

Results of radiation monotherapy for primary central nervous system lymphoma in the 1990s

PURPOSE

Results of radiation therapy for primary central nervous system lymphoma (PCNSL) were poor in the 1970-1980s, with most reported 5-year survival rates being less than 10%. To investigate whether the prognosis of PCNSL patients treated by radiation alone remains still poor, we investigated the results of radiation monotherapy in the 1990s.

METHODS AND MATERIALS

We collected data on 132 patients with histologically proven PCNSL treated by radiation alone in the 1990s from three nationwide or regional multiinstitutional studies conducted by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) Lymphoma Study Group or the Chubu Radiation Oncology Group. Follow-up data were updated as far as possible. Eleven patients who did not complete planned radiotherapy were included. The data were analyzed in relation to patient and tumor characteristics. The median patient age was 63 years, and the World Health Organization performance status (PS) was 3 or 4 in 40% of the patients. Multiple tumors were seen in 34%. Whole-brain irradiation with or without focal boost was used in 92%. The median radiation dose to the tumor site was 50 Gy (range, 8-74 Gy).

RESULTS

For all 132 patients, the median survival time was 18 months and the 5-year survival rate was 18.0%. For 62 patients with PS 0-3 and aged 16-65 years (i.e., those eligible for the European Organization for Research and Treatment of Cancer 20962 study), the median survival was 26 months and 5-year survival was 24%. The 5-year survival was 25% for patients 63 years old or younger, and 9.8% for those older than 63 years (p = 0.0005). The 5-year survival was 22% for patients with PS 0-2 and 13% for those with PS 3 or 4 (p = 0.0040). Multivariate analysis confirmed the negative influence of higher age on patient prognosis.

CONCLUSIONS

The results of radiation monotherapy for PCNSL appear to have improved as compared with those reported previously. The results of new treatment should be evaluated in light of this finding. Since most prospective studies on the combined treatment exclude poor PS and high-age patients, the 5-year survival rate of 30% may not be regarded as a marked improvement over radiation alone.

Response to chemotherapy and treating institution predict survival in primary central nervous system lymphoma

The majority of the available data on primary central nervous system lymphoma (PCNSL) derive from small unicentric or oligocentric studies. In this multicentre study, we evaluated the response, survival and toxicity in PCNSL patients after carmustine, methotrexate 1.5 g/m2, procarbazine and dexamethasone (BMPD) chemotherapy and searched for prognostic factors. Fifty-six patients received the BMPD protocol (dexamethasone was given only in course 1). The overall complete response rate to chemotherapy was 61% (34/56). Ten complete responders received whole-brain irradiation and 24 were not irradiated. Responders to chemotherapy had significantly longer median overall survival than non-responders (18.2 vs. 9.9 months, P = 0.02). Median survival was significantly longer at institutions accruing at least four patients than at those with fewer patients (31.5 vs. 9.5 months, P = 0.03).

Treatment of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare neoplasm that has captured popular attention because of its rising incidence and marked chemosensitivity. It is a non-Hodgkins B-cell lymphoma (NHL) that appears confined to the central nervous system (CNS) at presentation but may be multifocal within the brain or involve the leptomeninges or eyes at diagnosis. Like systemic lymphoma, it is highly sensitive to corticosteroids, and administration of steroids should be withheld until the diagnosis has been confirmed histologically. Currently, the initial treatment of choice incorporates high-dose methotrexate (HD-MTX) either as a single agent or in combination with other systemic chemotherapies. Whole-brain radiotherapy (WBRT) can be a highly effective treatment modality when combined with MTX, but the combination causes an unacceptably high incidence of severe permanent neurotoxicity, particularly in patients over age 60. Therefore, chemotherapy alone is the initial treatment of choice in older patients. This approach is also being explored in younger patients, but it is possible that deferring radiotherapy may compromise disease control. Consequently, the role of radiotherapy remains to be clarified in newly diagnosed younger patients with PCNSL.

Primary non-Hodgkin's lymphoma of the CNS treated with CHOD/BVAM or BVAM chemotherapy before radiotherapy: long-term survival and prognostic factors

PURPOSE

To assess the long-term survival and prognostic factors associated with the cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD)/carmustine, vincristine, methotrexate, and cytarabine (BVAM) and BVAM chemotherapy regimens followed by cranial radiotherapy in the treatment of primary central nervous system (CNS) non-Hodgkin lymphoma.

METHODS AND MATERIALS

Since 1986, high-dose methotrexate (1.5 g/m(2)), cytarabine, vincristine, and carmustine have been used in the BVAM chemotherapy regimen for primary CNS non-Hodgkin's lymphoma, with one cycle of CHOD given before BVAM in patients <or=70 years of age from 1990 onward.

RESULTS

The median age for the 77 patients treated was 60 years and the median follow-up of surviving patients was 3 years (range, 1.4-15.2 years). The complete response rate after chemotherapy was 62% and after additional radiotherapy was 73%. Multivariate analysis of overall survival showed age (p = 0.004), performance status (p = 0.007), and number of tumors (unifocal disease vs. multifocal disease; p = 0.005) to be statistically significant prognostic factors. Survival decreased with increasing age and performance status score. Using a prediction score giving 1 point for each adverse prognostic factor (age >or=60 years, performance status >or=2, and multifocal and/or meningeal disease [advanced stage]), a score of 0 (8 patients) was associated with a median survival of 55 months, a score of 1 (29 patients) of 41 months, a score of 2 (28 patients) of 32 months, and a score of 3 (12 patients) a median survival of 1 month (p <0.001). The actuarial overall survival for the 35 patients aged <60 years was 32.4% (95% confidence interval, 14.1-50.8%) at 10 years.

CONCLUSION

The Nottingham/Barcelona prediction score, which is similar to the International Prognostic Index, may be useful in comparing survival with different regimens studied in Phase II trials. Patients with primary CNS non-Hodgkin's lymphoma aged <60 years treated with CHOD/BVAM or BVAM followed by radiotherapy have a similar long-term survival to that of patients with large B cell non-Hodgkin's lymphoma at other extranodal sites.

Area under the curve of methotrexate and creatinine clearance are outcome-determining factors in primary CNS lymphomas

Although high-dose methotrexate (HD-MTX) is the most effective drug against primary CNS lymphomas (PCNSL), outcome-determining variables related to its administration schedule have not been defined. The impact on toxicity and outcome of the area under the curve (AUC(MTX)), dose intensity (DI(MTX)) and infusion rate (IR(MTX)) of MTX and plasmatic creatinine clearance (CL(crea)) was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-based combinations. Anticonvulsants were administered in 31 pts (69%). Age >60 years, anticonvulsant therapy, slow IR(MTX) (</=800 mgm(-2)h(-1)), and reduced DI(MTX) (</=1000 mgm(-2)wk(-1)) were significantly correlated with low AUC(MTX) values. Seven patients (16%) experienced severe toxicity, which was independently associated with slow CL(crea). A total of 18 (40%) patients achieved complete remission after chemotherapy, which was independently associated with slow CL(crea). In all, 22 patients were alive at a median follow-up of 31 months, with a 3-year OS of 40+/-9%; slow CL(crea) and AUC(MTX) >1100 micromol hl(-1) were independently associated with a better survival. Slow CL(crea) and high AUC(MTX) are favourable outcome-determining factors in PCNSL, while slow CL(crea) is significantly related to higher toxicity. AUC(MTX) significantly correlates with age, anticonvulsant therapy, IR(MTX), and DI(MTX). These findings, which seem to support the choice of an MTX dose >/=3 gm(-2) in a 4-6-h infusion, every 3-4 weeks, deserve to be assessed prospectively in future trials. MTX dose adjustments in patients with fast CL(crea) should be investigated.

Treatment of primary central nervous system lymphoma in the elderly

Although the incidence of primary central nervous system lymphoma has recently declined among people with acquired immunodeficiency syndrome, the incidence of primary central nervous system lymphoma remains high among the immunocompetent population >/=60 years of age. Elderly patients represent an important subgroup that accounts for approximately half of primary central nervous system lymphoma cases. Radiotherapy (RT) alone has produced disappointing results in the elderly. Improved clinical outcomes have been achieved with high-dose methotrexate-based chemotherapy regimens in combination with whole-brain RT. Unfortunately, combination therapy exposes elderly patients to a high risk of severe delayed neurotoxicity in up to 80%. Chemotherapy alone may be the best approach for treating elderly patients and appears to be more effective than RT, while considerably reducing the risk of neurotoxicity. Clinical studies are needed to define the optimal chemotherapy regimen for the elderly in an effort to delay or completely avoid the need for RT.

Chemotherapy alone as initial treatment for primary CNS lymphoma in patients older than 60 years: a multicenter phase II study (26952) of the European Organization for Research and Treatment of Cancer Brain Tumor Group

PURPOSE

To assess the efficacy and toxicity of chemotherapy alone in patients older than 60 years with primary CNS lymphoma.

PATIENTS AND METHODS

Fifty patients with a median age of 72 years and a median Karnofsky performance score (KPS) of 50 were eligible for this multicenter phase II study. The protocol consisted of high-dose methotrexate (MTX), lomustine, procarbazine, methylprednisolone, and intrathecal chemotherapy with MTX and cytarabine. The patients received one induction cycle; if objective response was achieved, five additional maintenance cycles were administered every 6 weeks. The median follow-up of patients was 3 years.

RESULTS

Twenty four patients (48%) achieved an objective response (compete response [CR], 42%; partial response, 6%), with a median duration of CR of 27 months (range, 3 to 47+ months). Overall median survival time was 14.3 months, and 1-year progression-free survival was 40% (95% confidence interval [CI], 26% to 53%). Myelosuppression was the most frequent side effect, with grade 3 to 4 neutropenia in 19% of patients. One patient died during chemotherapy, as a result of pulmonary embolism. Most patients improved or preserved their cognitive functions (47% and 45% of the patients, respectively) and KPS (36% and 52% of the patients, respectively) until relapse, whereas cognitive and KPS decline attributed to delayed treatment neurotoxicity occurred in 8% and 12% patients, respectively.

CONCLUSION

In the elderly, this chemotherapy regimen compares favorably with radiotherapy (RT) alone and reduces considerably the risk of delayed neurotoxicity associated with combined chemoradiotherapy. Chemotherapy alone is an appropriate strategy in older patients to delay or avoid RT.

Primary ocular lymphoma: clinical features, diagnosis, and treatment

Primary ocular lymphoma involves the globe in the absence of any systemic or central nervous system lymphoma. Diagnosis is frequently delayed and often made only after the tumor has progressed to the brain and meninges. Clinical features, cues in ancillary tests, and immunologic and molecular advances that support the diagnosis are reviewed. The current treatment options are discussed. Although advances have been made, the optimal treatment for primary ocular lymphoma remains to be identified

Primary Central Nervous System Lymphoma

Standard therapy does not exist for the treatment of primary central nervous system lymphoma. This is because of low patient numbers, slow accrual to clinical trials, and the absence of phase III randomized clinical trials. Neuro-oncologists agree that whole brain irradiation alone is no longer the best treatment option; treatment should include high-dose methotrexate chemotherapy, and treatment strategies must combine efficacy without untoward toxicity. However, beyond this, there is no widespread consensus. Significant neurocognitive toxicity has been associated with combined chemotherapy-radiation regimens, especially in elderly patients. This has prompted many to defer radiation therapy in all patients except those that refuse chemotherapy, those that have a partial response to chemotherapy, or those that have disease progression through chemotherapy. There is supporting evidence for this approach; however, confirmatory data from multicenter clinical trials and 5-year survival rates are unavailable. This underscores the importance of ongoing clinical trials.

Intraocular lymphoma

There are two distinct forms of intraocular lymphoma. One originates within the central nervous system (CNS) and is called primary CNS lymphoma. The second form arises outside the CNS and metastasizes to the eye. When primary CNS lymphoma initially involves the retina, it is named primary intraocular lymphoma (PIOL). Although PIOL is a rare malignancy, the incidence has dramatically increased in the past 15 years. Typical clinical manifestations include blurred vision and floaters. Ophthalmic examination reveals vitreitis and subretinal infiltrates. Diagnosis of PIOL can be difficult and requires neuroimaging, examination of the cerebrospinal fluid and/or vitreous. Molecular analysis detecting immunoglobulin gene rearrangements and ocular cytokine levels showing elevated interleukin (IL)-10 with an IL-10 to IL-6 greater than 1.0 are helpful adjuncts for the diagnosis. Treatment includes systemic chemotherapy and radiation with current regimens favoring the use of chemotherapy first. In contrast, metastatic systemic lymphoma, like other metastatic ocular tumors, is usually confined to the uvea, in particular the choroid. Compared with PIOL, metastatic systemic lymphomas have a much lower prevalence, better prognosis, and are less likely to create a diagnostic dilemma.

Primary nervous system lymphoma

Primary nervous system lymphoma (PNSL) is a rare type of non-Hodgkin's lymphoma confined to the nervous system. Although significant progress has been made in the treatment of PNSL over the past decade, patients with this disease are rarely cured. Until recently, whole brain radiation therapy has been the standard treatment for PNSL. However, whole brain radiation therapy is associated with a high relapse rate and late neurotoxicity after chemotherapy, especially in patients older than 60 years of age. Methotrexate-based chemotherapy has become the standard approach to treat patients with newly diagnosed PNSL. Ongoing research efforts are focused on identifying chemotherapeutic agents with good antilymphoma activity that penetrate the blood-brain barrier. The roles of intrathecal chemotherapy and blood-brain barrier disruption are not fully defined. Given the rarity of this tumor, patients with PNSL should be referred to tertiary cancer centers where ongoing clinical trials are underway to identify the optimal treatment of PNSL.

Primary central nervous system lymphoma in immunocompetent adults: poor results mainly associated with high treatment related toxicities

Treatment of primary central nervous system lymphoma (PCNSL) occurring in immunocompetent patients remains controversial but long-term survival has been reported in patients treated by chemotherapy regimens containing non-lipophilic drugs. We report 34 consecutive PCNSL patients treated at our institution by a chemotherapy regimen that combined drugs crossing and not crossing the blood-brain barrier. Early toxicity was high as 10 of 17 deaths that occurred within the first year of diagnosis were treatment related. Infections and thromboembolism were the main causes of toxicity. We concluded that the use of drugs of uncertain efficacy in these particularly fragile patients is questionable.

Strategies for increasing drug delivery to the brain: focus on brain lymphoma

The blood-brain barrier (BBB) is a gate that controls the influx and efflux of a wide variety of substances and consequently restricts the delivery of drugs into the central nervous system (CNS). Brain tumours may disrupt the function of this barrier locally and nonhomogeneously. Therefore, the delivery of drugs to brain tumours has long been a controversial subject. The current concept is that inadequate drug delivery is a major factor that explains the unsatisfactory response of chemosensitive brain tumours. Various strategies have been devised to circumvent the BBB in order to increase drug delivery to the CNS. The various approaches can be categorised as those that attempt to increase delivery of intravascularly administered drugs, and those that attempt to increase delivery by local drug administration. Strategies that increase delivery of intravascularly injected drugs can manipulate either the drugs or the capillary permeability of the various barriers (BBB or blood-tumour barrier), or may attempt to increase plasma concentration or the fraction of the drug reaching the tumour (high-dose chemotherapy, intra-arterial injection). Neurotoxicity is a major concern with increased penetration of drugs into the CNS or when local delivery is practised. Systemic toxicity remains the limiting factor for most methods that use intravascular delivery. This review evaluates the strategies used to increase drug delivery in view of current knowledge of drug pharmacokinetics and its relevance to clinical studies of chemosensitive brain tumours. The main focus is on primary CNS lymphoma, as it is a chemosensitive brain tumour and its management routinely utilises specialised strategies to enhance drug delivery to the affected CNS compartments.

Novel chemotherapeutic approaches to brain tumors

In reviewing the numerous investigational drug trials for patients with anaplastic gliomas over the past 20 years, it would be fair to say that there have been more than a few disappointments and that the real impact of many of these therapies on patients' duration and quality of survival has been minor at best. It is also fair to state that there has been progress in developing new types of chemotherapy and other agents, in devising new treatment strategies, and in gaining a deeper understanding of the problems that must be overcome to treat patients with anaplastic gliomas successfully. The past several years have seen the realization that oligodendroglioma, primary CNS lymphoma, and medulloblastoma are sensitive to chemotherapy treatments. It is hoped that future studies will delineate better the optimal use of chemotherapy for these tumors.

Primary nervous-system lymphoma

Primary nervous-system lymphoma is a rare type of non-Hodgkin lymphoma, which is confined to the nervous system. This disease is managed quite differently from the usual treatment of either primary brain tumours or systemic non-Hodgkin lymphoma. Although whole-brain radiotherapy results in responses in more than 90% of cases, this treatment is associated with high relapse rates and with delayed neurotoxicity in elderly patients. First-generation chemotherapy regimens used successfully in systemic non-Hodgkin lymphoma (eg cyclo-phosphamide, adriamycin, vincristine, and prednisone) are ineffective in primary nervous-system lymphoma, partly because of the blood-brain barrier. Median survival of patients treated with radiotherapy alone or chemotherapy plus radiotherapy is similar, and ranges from 10 to 16 months. The addition of methotrexate-based chemotherapy has improved survival for these patients, extending median survival to more than 30 months. When used alone, methotrexate-based chemotherapy is associated with significantly fewer treatment-associated toxic effects. Leptomeningeal lymphoma and intraocular lymphoma are topics of particular relevance in primary nervous-system lymphoma and are addressed in this review.

CHOD/BVAM regimen plus radiotherapy in patients with primary CNS non-Hodgkin's lymphoma

PURPOSE

To assess the efficacy and toxicity, including long-term neurotoxicity, of combined therapy with the CHOD/BVAM regimen given before cranial radiotherapy in the treatment of primary CNS lymphoma (PCNSL).

METHODS AND MATERIALS

Thirty-one consecutive patients with PCNSL were treated with one cycle of cyclophosphamide, doxorubicin, vincristine, and dexamethasone (CHOD) and two of carmustine (BCNU), vincristine, cytosine arabinoside, and methotrexate (BVAM), followed by cranial radiotherapy (45 Gy whole brain plus a 10-Gy boost for single lesions). The median age was 59 years (range 21-70) and 39% had poor performance status. The median follow-up of patients was 4.1 years (range 2.7-9.0).

RESULTS

Twenty-one patients had no PCNSL at the end of treatment. The 5-year actuarial probability of survival was 31% (95% confidence interval [CI]: 11%-57%), with a median survival of 38 months. Patients < 60 years had a survival significantly longer than those > or = 60 years (4-year survival: 58% (95% CI: 34-82%) vs. 29% (95% CI: 5-53%), respectively; p = 0.04). Two patients died during chemotherapy from pulmonary embolism and bronchopneumonia, respectively, with no evidence of PCNSL at the autopsy. Dementia probably related to treatment occurred in 5 (62%) of the 8 patients 60 years and older, and 4 of them died without evidence of relapse of PCNSL. Dementia correlated with developing brain atrophy and leuco-encephalopathy on serial CT or MR scans.

CONCLUSION

This regimen can be given with the planned dose intensity to patients aged less than 70 years, and produces better survival than that reported with radiotherapy alone; however, dementia occurs in the majority of patients aged 60 years of age or more.