Phase I study of intraventricular administration of rituximab in patients with recurrent CNS and intraocular lymphoma

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 involvement in adult patients with diffuse large B-cell lymphoma: Influence of rituximab

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone)-like chemotherapy, in combination with rituximab (R-CHOP-like), improves outcome in patients with diffuse large B-cell lymphoma (DLBCL). We aimed to investigate the impact of rituximab on central nervous system (CNS) disease in adult patients. We studied 315 patients (aged 18-60 years old) from six hospitals between July 2003 and May 2008. All patients received CHOP-like (n=165) or R-CHOP-like (n=150) regimen every 3 weeks. With a median follow-up of 3.69 years, 10 patients (3.17%) developed CNS disease. The cumulative risk of CNS occurrence was not significantly different between the two treatment groups (P=0.871). We conclude that the addition of rituximab did not reduce the risk of CNS disease in adult patients with DLBCL.

Intraventricular rituximab and systemic chemotherapy for treatment of central nervous system post-transplant lymphoproliferative disorder after kidney transplantation

PTLD of the CNS is a rare complication of solid organ transplantation, and there are only case reports/series available in the literature. Current literature suggests that CNS PTLD carries a worse prognosis than PTLD outside the CNS, and most are of B-cell lineage, predominantly monomorphic, and are associated with EBV infection. Because this disorder is so rare, there is no standard chemotherapy for pediatric patients with CNS PTLD and reported therapies for EBV-associated CNS PTLD are heterogeneous with mixed results. Since outcomes of CNS PTLD are historically poor, we attempted to develop a novel therapeutic treatment regimen. Based on a review of the literature and with the help of a multidisciplinary team, we created a regimen of chemotherapy that included dexamethasone and high-dose methotrexate in addition to intravenous and intraventricular Rituximab in two pediatric patients. The intraventricular chemotherapy succeeded in shrinking the tumor in both of our patients; however, as shown in the second case, the clinical outcome depends on the location of the tumor. Systemic and intraventricular therapies hold promise in the management of EBV-associated CNS PTLD; however the rarity of this entity prevents the development of well-designed studies necessary for the establishment of an evidence-based treatment standard.

Intrathecal therapy with rituximab in central nervous system involvement of post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) caused by Epstein-Barr virus (EBV) is a severe complication in high-risk allogeneic hematopoietic stem cell transplant (HSCT) recipients. Central nervous system (CNS) involvement of PTLD is a very rare event in patients with HSCT. As no established standard therapy in CNS-EBV-PTLD is available, the aim of this study was analysis of the safety and efficacy of intrathecal rituximab therapy in a group of eight children and adolescents with CNS-EBV-PTLD. Seven patients responded to therapy: all clinical symptoms and EBV-DNA viral load resolved after a median 2 (range: 1-7) doses of rituximab. However, some magnetic resonance imaging (MRI) changes in brain scan persisted in two patients. In all patients, except one, no adverse events of the therapy were observed. In conclusion, intrathecal rituximab administration seems to be an effective and safe method of treatment of CNS-EBV-PTLD in pediatric stem cell recipients. We recommend this treatment modality for further investigation.

Leptomeningeal metastasis from systemic cancer

PURPOSE OF REVIEW

Leptomeningeal metastasis (LM) is an uncommon, usually late, complication of cancer. This article discusses the clinical presentation, diagnosis, prognosis, and treatment of LM.

RECENT FINDINGS

Neither gadolinium-enhanced MRI nor CSF cytology is adequately sensitive to diagnose all cases of LM.

SUMMARY

Patients with LM classically present with multifocal neurologic symptoms and signs, and the diagnosis is made via MRI, CSF cytologic analysis, or both. Treatment is palliative in nature and can involve focal radiation to symptomatic sites, systemic chemotherapy with agent(s) that cross the blood-brain barrier, or intrathecal delivery of chemotherapy. Patients may present with or later develop signs of hydrocephalus; ventriculoperitoneal shunting can provide symptomatic relief in certain patients. Overall prognosis is poor, with a median survival typically in the range of 2 to 3 months.

Therapeutic approaches for HER2-positive brain metastases: circumventing the blood-brain barrier

We aim to summarize data from studies of trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and brain metastasis and to describe novel methods being developed to circumvent the blood-brain barrier (BBB). A literature search was conducted to obtain data on the clinical efficacy of trastuzumab and lapatinib in patients with HER2-positive MBC and brain metastasis, as well as the transport of therapeutic molecules across the BBB. Trastuzumab-based therapy is the standard of care for patients with HER2-positive MBC. Post hoc and retrospective analyses show that trastuzumab significantly prolongs overall survival when given after the diagnosis of central nervous system (CNS) metastasis; this is probably attributable to its control of extracranial disease, although trastuzumab may have a direct effect on CNS disease in patients with local or general perturbation of the BBB. In patients without a compromised BBB, trastuzumab is thought to have limited access to the brain, because of its relatively large molecular size. Several approaches are being developed to enhance the delivery of therapeutic agents to the brain. These include physical or pharmacologic disruption of the BBB, direct intracerebral drug delivery, drug manipulation, and coupling drugs to transport vectors. Available data suggest that trastuzumab extends survival in patients with HER2-positive MBC and brain metastasis. Novel methods for delivery of therapeutic agents into the brain could be used in the future to enhance access to the CNS by trastuzumab, thereby improving its efficacy in this setting.

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.

Leptomeningeal disease

Leptomeningeal metastasis (LMD) is a lethal complication caused by a variety of cancers, typically developing late in the disease course. It is associated with major neurologic disabilities and short survival. The incidence of LMD may increase because of longer survival of patients who have cancer, and because of the use of newer large-molecule therapies with poor central nervous system penetration. To achieve improved outcomes for patients who have LMD, new treatments need to reach the meninges and cerebrospinal fluid and interact with relevant molecular targets. Some of the agents currently in testing may contribute to this goal. To allow for better outcomes through earlier treatment, advances in diagnosis are needed. By using agents with higher therapeutic indices, in patients with a lower burden of disease (identified earlier with clinical or molecular markers) it should be possible to achieve gradual improvements in outcomes for patients suffering from this devastating disease.

Intrathecal tripeptidyl-peptidase 1 reduces lysosomal storage in a canine model of late infantile neuronal ceroid lipofuscinosis

Late infantile neuronal ceroid lipofuscinosis (LINCL) is caused by mutations in the gene encoding tripeptidyl-peptidase 1 (TPP1). LINCL patients accumulate lysosomal storage materials in the CNS accompanied by neurodegeneration, blindness, and functional decline. Dachshunds homozygous for a null mutation in the TPP1 gene recapitulate many symptoms of the human disease. The objectives of this study were to determine whether intrathecal (IT) TPP1 treatment attenuates storage accumulation and functional decline in TPP1-/- Dachshunds and to characterize the CNS distribution of TPP1 activity. TPP1 was administered to one TPP1-/- and one homozygous wild-type (WT) dog. An additional TPP1-/- and WT dog received vehicle. Four IT administrations of 32 mg TPP1 formulated in 2.3 mL of artificial cerebrospinal fluid (aCSF) or vehicle were administered monthly via the cerebellomedullary cistern from four to seven months of age. Functional decline was assessed by physical and neurological examinations, electrophysiology, and T-maze performance. Neural tissues were collected 48 h after the fourth administration and analyzed for TPP1 activity and autofluorescent storage material. TPP1 was distributed at greater than WT levels in many areas of the CNS of the TPP1-/- dog administered TPP1. The amount of autofluorescent storage was decreased in this dog relative to the vehicle-treated affected control. No improvement in overall function was observed in this dog compared to the vehicle-treated TPP1-/- littermate control. These results demonstrate for the first time in a large animal model of LINCL widespread delivery of biochemically active TPP1 to the brain after IT administration along with a decrease in lysosomal storage material. Further studies with this model will be necessary to optimize the dosing route and regimen to attenuate functional decline.

Leptomeningeal Metastasis: Challenges in Diagnosis and Treatment

As therapeutic options and supportive care for the treatment of neoplastic disease have improved, there has been an associated increase in the incidence of leptomeningeal disease. In this review, the clinical presentation, natural history, diagnostic evaluation, and treatment options for this often devastating sequela of solid tumors, lymphoma, and leukemia will be summarized. The therapeutic efficacy of ionizing radiation, systemic agents, and intrathecal drugs will be examined from the existing literature. Additionally the pathophysiology, which in part defines the therapeutic limitations in approaching this patient population, will be discussed in order to assist in individualized clinical decision making.

Neoplastic meningitis resulting from hematological malignancies: pharmacokinetic considerations and maximizing outcome

Neoplastic meningitis, also known as leptomeningeal metastases, is a complication of various types of cancer that occurs when tumor cells enter the cerebrospinal fluid (CSF), travel along CSF pathways and grow. Treatment options include drug delivery directly into the CNS or systemic administration for targeted action in the CNS. CNS drug delivery is limited by the blood-brain barrier and the blood-CSF barrier. It may be possible to partially overcome this by using high-dose systemic therapy; however, this is done at the possible expense of increased systemic toxicity. Intra-CSF drug delivery bypasses the blood-brain barrier and allows direct access of the chemotherapeutic agent to the CSF. Because neoplastic meningitis occurs in an increasingly large percentage of all cancer patients, it is imperative to optimize drug delivery to the CSF and meninges. Both the pharmacokinetic profile of the chemotherapeutic agent and the site of administration influence therapeutic efficacy. Achieving prolonged therapeutic cytotoxic drug concentrations and even distribution in the CSF will improve efficacy. In this article we summarize data on the efficacy, safety and outcome of high-dose systemic and intra-CSF treatments.

Novel approaches to treating leptomeningeal metastases

Leptomeningeal metastasis is a devastating complication of the central nervous system in patients with late-stage solid or hematological cancers. Leptomeningeal metastasis results from the multifocal seeding of the leptomeninges by malignant cancer cells. Although central nervous system metastasis usually presents in patients with widely disseminated and progressive late-stage cancer, malignant cells may spread to the cerebrospinal fluid during earlier disease stages in particularly aggressive cancers. Treatment of leptomeningeal metastasis is largely palliative but will often provide stabilization and protection from further neurological deterioration and improve quality of life. There is a need to raise awareness of the impact of leptomeningeal metastases on cancer patients and its known and putative biological basis. Novel diagnostic approaches include identification of biomarkers that may stratify the risk for developing leptomeningeal metastasis. Current therapies can be used more effectively while waiting for advanced treatments to be developed.

Evaluation of intraorbital injection of rituximab for treatment of primary ocular adnexal lymphoma: a pilot study

An interventional pilot study to assess the tolerability and activity of the intralesional injection of rituximab, a chimeric mAb that targets the CD20 antigen, in patients with orbital B-cell lymphoma. Five patients received four intralesional injections (one injection a week) of rituximab together with ropivicaine 2%. Side-effects and tumor response were assessed after each injection and during the follow-up (20 months). Two patients obtained complete remission of the intraorbital lesion. Two patients showed incomplete response after induction therapy and received planned escalating rituximab doses, obtaining regression of subjective symptoms. One patient did not achieve tumor regression after the first injection and underwent systemic treatment. This small exploratory study suggests that intralesional rituximab is a well-tolerated treatment for patients with primary ocular adnexal lymphoma. These preliminary findings suggest that intralesional rituximab is a well-tolerated strategy in anterior intraorbital lesion localization of lymphoma.

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.

[Leptomeningeal meningitis related to breast cancer overexpressing HER2: is there a place for a more specific treatment?]

Leptomeningeal metastases are very commonly associated with breast cancer. The prognosis is very poor in the short term with an overall median survival less than 6 months. Based on pragmatic and historical considerations intrathecal chemotherapy (IT) are considered to be the adequate treatment. However overall results are disappointing. Despite specific and symptomatic treatment, improvement in survival and quality of life remains very modest, highlighting the importance for ongoing research for developing new molecules or on improving the use a better use of those available today. The incidence of leptomeningeal metastases is particularly marked in cases of overexpression of HER2. The main hypothesis is there may be a better control of extra-cerebral localisations with trastuzumab therefore intra-cerebral recurrences may be encountered preferentially as they are not reached by this high molecular weight monoclonal antibody (148  kD). Analyses performed in the cerebrospinal fluid following intravenous trastuzumab showed extremely low levels of the antibody and support the hypothesis that leptomeningeal metastasis of HER2-overexpressing breast carcinoma remain potentially sensitive to HER2-type receptor inhibition by a target agent under the condition of by-passing the meningeal blood brain barrier. Intra-ventricular or IT administered with trastuzumab would reach high loco-regional therapeutic concentrations in the cerebro-meningeal without risk for normal non-expressing HER2 leptomeningeal tissue. This strategy has been successfully tested on several animal models. A limited number of administrations in humans have been described in the literature, with weekly doses up to 100  mg. No specific toxicity has been described and some data suggest a potential benefit in survival despite the real difficulties for adequate interpretations. Furthermore, a multicentric phase I-II clinical trial, of which the Curie institute is the sponsor and investigating the intra-thecal administration and the efficacy of the trastuzumab will begin very soon. More studies are needed to measure the exact impact of small molecule inhibitors of tyrosine kinase on the leptomeningeal localizations.

Pharmacotherapy for primary CNS lymphoma: progress beyond methotrexate?

Studies conducted in the 1990s have established that high-dose methotrexate-based chemotherapy added to whole-brain radiotherapy improves survival in primary CNS lymphoma (PCNSL). However, radiotherapy-related delayed neurotoxicity has emerged as a serious complication of chemo-radiotherapy, particularly in the elderly. Unfortunately, omitting radiotherapy results in decreased progression-free survival, and therefore establishing more effective chemotherapy regimens is necessary in order to improve the number of long-term remissions. Recent studies have suggested that a combination of drugs is superior to single-agent methotrexate, but the optimal chemotherapy combination and the role of alternative consolidation treatments such as reduced-dose radiotherapy and high-dose chemotherapy with stem cell rescue remain to be defined. In this article, we review the multiple chemotherapy options reported in newly diagnosed and in progressive/refractory PCNSL, including recently reported and ongoing clinical trials, as well as future perspectives.

High-dose methotrexate with R-CHOP therapy for the treatment of patients with primary central nervous system lymphoma

We describe MR-CHOP therapy, a novel treatment regimen consisting of high-dose methotrexate and R-CHOP that provides systemic anti-tumor activity with penetration of the blood-brain barrier in patients with newly diagnosed primary central nervous system lymphoma. The MR-CHOP regimen was administered with 2 g/m(2) of methotrexate and 375 mg/m(2) of rituximab on day 1, 750 mg/m(2) of cyclophosphamide on day 3, 50 mg/m(2) of doxorubicin on day 3, 1.4 mg/m(2) of vincristine on day 3 and 100 mg of prednisolone on days 1-5 in this pilot study of seven patients. Six cycles of MR-CHOP therapy were administered every 3 weeks, followed by high-dose chemotherapy with stem cell rescue in young patients, or an additional two cycles of 4 g/m(2) methotrexate and rituximab in older patients. The overall response rate was 100%, with 85.7% complete remission (CR). One patient showed partial response, relapsed and subsequently died. Another relapsed following CR, and was rescued by further salvage therapy. The others survive without relapse at a median observation period of 24 months. Hematological toxicity included grade 4 leukocytopenia in 4/7 and neutropenia in 5/7, which were transient and tolerated well. Non-hematological toxicities were tolerated well. The efficacy of this novel regimen as remission induction therapy was found to be promising in this pilot study, although the number of patients was small and follow-up short.

Treatment of HIV-related primary central nervous system lymphoma with AZT high dose, HAART, interleukin-2 and foscarnet in three patients

PURPOSE

Combined immunomodulatory and antiviral treatment was administered to three patients with newly diagnosed HIV-associated primary central nervous system lymphoma (PCNSL) in an attempt to improve outcomes.

PATIENTS AND METHODS

Three patients from our institution who were recently diagnosed with HIV-associated PCNSL received intravenous azidothymidine (AZT) 1.6 gr. bid for two weeks, followed by oral AZT 250mg bid from day 15. In addition, complementary highly active antiretroviral therapy (HAART) with a second nucleoside reverse transcriptase inhibitor (NRTI) plus one protease inhibitor (PI) and interleukin 2 (IL-2) subcutaneously 2 million units twice daily (bid) plus foscarnet 90mg/kg bid were administered on days 1-14. One patient received anti-Epstein-Barr virus (EBV)-maintenance therapy with ganciclovir, followed by cidofovir.

RESULTS

All patients experienced progressive disease while on induction therapy, and switched early to whole-brain radiation therapy (WBRT) as second line-treatment. No grade 3 or 4 toxicities were observed. Two patients died on days 50 and 166 respectively due to progressive disease. The third patient with histo?logically proven lymphoproliferation and only suspected PCNSL remained alive at 53 months. He was on HAART and remained clinically and neurologically stable.

CONCLUSION

Although IL-2, HAART, high-dose AZT and foscarnet are used for other HIV-related conditions, they did not demonstrate benefit in lymphoma remission for 2 HIV- associated PCNSL patients. The third patient went into delayed remission after additional radiotherapy and was in good clinical and neurological health status over 53 months after diagnosis.

Imaging and therapy with rituximab anti-CD20 immunotherapy in an animal model of central nervous system lymphoma

PURPOSE

To evaluate the effect of rituximab monoclonal antibody (mAb) on MRI tumor volumetrics and efficacy in a rat model of central nervous system (CNS) lymphoma when delivery to the brain was optimized with osmotic blood-brain barrier disruption (BBBD).

EXPERIMENTAL DESIGN

Female nude rats with intracerebral MC116 human B-cell lymphoma xenografts underwent baseline MRI and were randomized into 5 groups (n = 6 per group): (i) BBBD saline control; (ii) methotrexate with BBBD; (iii) rituximab with BBBD; (iv) rituximab and methotrexate with BBBD; and (v) intravenous rituximab. Tumor volumes were assessed by MRI at 1 week, and rats were followed for survival.

RESULTS

BBBD increased delivery of yttrium-90-radiolabeled mAb in the model of CNS lymphoma. Control rats showed 201 ± 102% increase in tumor volume on MRI 1 week after entering the study and median 14-day survival (range: 6-33). Tumor growth on MRI was slowed in the methotrexate treatment group, but survival time (median: 7 days; range: 5-12) was not different from controls. Among 17 evaluable rats treated with rituximab, 10 showed decreased tumor volume on MRI. All rituximab groups had increased survival compared with control, with a combined median of 43 days (range: 20-60, P < 0.001). There were no differences by route of delivery or combination with methotrexate.

CONCLUSIONS

Rituximab was effective at decreasing tumor volume and improving survival in a model of CNS lymphoma and was not affected by combination with methotrexate or by BBBD. We suggest that rituximab warrants further study in human primary CNS lymphoma.

Ocular relapse of primary brain lymphoma in immunocompetent patient, treated with intrathecal rituximab

Primary brain lymphoma is a rare variant of extranodal non-Hodgkin's B-cell lymphoma. In >90% of cases, this is diffuse large B-cell lymphoma with CD20 expression and is confined to the brain, meninges, spinal cord, and eyes. It accounts for fewer than 7% of primary brain tumors. Its incidence has been rising in recent years in immunocompetent patients in their fifth and sixth decades. The rate of relapse after initial therapy based on high-dose methotrexate and/or total brain irradiation is high. There is no consensus for treating relapse, which ranges from retreatment with high doses of methotrexate, polychemotherapy, high doses of chemotherapy backed up by autologous stem-cell transplant to intrathecal chemotherapy, with widely differing results. Given the lack of consensus and poor results, new therapy options have appeared, including immunotherapy with rituximab. At a systemic level, alongside chemotherapy, its results are very modest and limited due to the low concentration it reaches in cerebrospinal fluid (CSF). However, its intrathecal and intraventricular use, though only isolated cases have been reported, has provided promising results.

Leptomeningeal metastasis

PURPOSE OF REVIEW

Leptomeningeal metastasis occurs in approximately 5% of all patients with cancer. This review summarizes recent literature regarding methods of diagnosis and treatment of leptomeningeal metastasis.

RECENT FINDINGS

Staging of leptomeningeal metastasis should include contrast-enhanced brain and spine MRI, and though controversial, radionuclide cerebrospinal fluid (CSF) flow study. Treatment of leptomeningeal metastasis often requires involved-field radiotherapy to bulky or symptomatic disease sites as well as intra-CSF and systemic chemotherapy. The use of high-dose systemic therapy may benefit patients with leptomeningeal metastasis and obviate the need for intra-CSF chemotherapy. Intra-CSF drug therapy primarily utilizes one of three chemotherapeutic agents [i.e. methotrexate, cytosine arabinoside (both free and liposomal) and thio-tetraethylenepentamine] administered by a variety of schedules either by intralumbar or intraventricular drug delivery. Novel intra-CSF agents increasingly utilized in the treatment of leptomeningeal metastasis are targeted mAbs such as rituximab and trastuzumab.

SUMMARY

Although treatment of leptomeningeal metastasis is palliative with median patient survival of 2-3 months, treatment may afford stabilization and protection from further neurologic deterioration in patients with leptomeningeal metastasis.

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.

Diagnosis and individualized therapy of neoplastic meningitis

Neoplastic meningitis is a diffuse dissemination of tumor cells into the cerebrospinal fluid (CSF) and/or leptomeninges. It occurs in approximately 5-10% of malignant diseases, most often in breast cancer, lung cancer, melanoma or B-cell lymphoma. Symptoms of neoplastic meningitis are head or back pain, cranial nerve palsies, diffuse radicular symptoms or psychiatric disturbances. MRI shows nodular contrast enhancement lining CSF spaces. Positive CSF cytology requires optimal sampling and processing. Treatment must be individually shaped: the CSF dissemination may be treated with intrathecal chemotherapy with methotrexate or cytarabinoside (Ara-C). Liposomal Ara-C is distributed over the entire CSF space even after lumbar application and maintains cytotoxic levels for at least 2 weeks. Radiotherapy should be applied only to symptomatic solid spinal manifestations or fast progressing cranial nerve palsies. Systemic chemotherapy is needed to control solid manifestations or, in the case of substances entering the CSF, to support intrathecal chemotherapy.

High-dose intravenous rituximab for multifocal, monomorphic primary central nervous system posttransplant lymphoproliferative disorder

Primary central nervous system (CNS) posttransplant lymphoproliferative disorder (PTLD) is a well-recognized but rare complication of solid organ transplantation. Most of these disorders are B-cell in origin and generally carry poor prognosis. Rituximab, an anti-CD20 monoclonal antibody, has been used effectively in patients with systemic PTLD. However, its role in primary CNS PTLD is doubtful because it does not cross blood-brain barrier efficiently (<5%). Also, mechanisms, by which rituximab operates are not optimally effective in CNS. Here, we describe a renal transplant patient with monomorphic, multifocal, CD20-positive, primary B-cell CNS PTLD, who was treated with high-dose intravenous rituximab given in dose-escalation protocol, which has been used effectively for the patients with chronic lymphocytic leukemia. At 1-year follow-up, magnetic resonance imaging (MRI) showed complete resolution. High-dose rituximab may have a role in highly selected patients with primary CNS PTLD.

Treatment of central nervous system lymphoma in rats with intraventricular rituximab and serum

B cell lymphomas often develop in the central nervous system (CNS). Although rituximab (RTX) has been widely used for most B cell lymphomas, the efficacy for CNS lymphomas has yet to be elucidated. A major concern is that RTX might not reach lymphoma lesions, and either the antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity might not substantially operate in the CNS environment. Here we investigated the potential usefulness of co-administering RTX and human serum intraventricularly in nude rats carrying human B cell lymphomas in the CNS. Raji, a CD20-positive lymphoma cell line, was inoculated into the cerebrum of F344 (rnu/rnu) nude rats. After several days, RTX and human serum were delivered into the ipsilateral lateral ventricle via a cannula. Intraventricularly administered RTX was localized specifically at the lymphoma lesions, indicating that RTX penetrated the ependymal layer of the lateral ventricle to reach the tumor lesion, where it specifically bound to the lymphoma cells. The combination of RTX and serum (n = 12), but not RTX alone (n = 13), significantly extended the survival of the rats (P = 0.049). Intraventricular administration of RTX and serum in a rat/human CNS lymphoma model might be a potential novel treatment for CNS lymphomas of B cell origin. Clinical trials are warranted.

Role of Intrathecal Rituximab and Trastuzumab in the Management of Leptomeningeal Carcinomatosis

Objective:

To review evidence for the use of intrathecal rituximab and trastuzumab in the management of leptomeningeal carcinomatosis.

Data Sources:

A search of MEDLINE (1966–July 2010) and International Pharmaceutical Abstracts (1970–July 2010) was performed using search terms intrathecal, trastuzumab, rituximab, and monoclonal antibody. Additionally, American Society of Clinical Oncology, San Antonio Breast Conference, American Association for Cancer Research, and American Society of Hematology meeting abstracts were searched.

Study Selection and Data Extraction:

Publications were reviewed for inclusion. Those reporting use of rituximab and trastuzumab intrathecally are reviewed and include 1 Phase 1 trial, 2 small prospective studies, 1 case series, and 15 case reports.

Data Synthesis:

The treatment of leptomeningeal carcinomatosis is challenging due to the presence of the blood–brain barrier. Numerous systemically administered therapies do not readily penetrate into the site of leptomeningeal disease and have been ineffective. Intrathecal administration of 2 monoclonal antibodies (trastuzumab and rituximab) has been investigated in case reports and case series. Additionally, intrathecal rituximab has been investigated in a Phase 1 study. Survival after intrathecal trastuzumab ranged from 39 days to greater than 72 months and the drug was well tolerated, with no adverse events attributed to it. Doses used in these reports ranged from 5 to 100 mg. Survival after intrathecal rituximab ranged from 1.1 weeks to greater than 3.5 years. In the Phase 1 trial, the maximum tolerated rituximab dose was 25 mg and 60% of patients responded. Four of the 6 responding patients experienced a complete response. Intrathecal rituximab exhibited minor toxicities that resolved quickly without long-term effects.

Conclusions:

Reports suggest that both trastuzumab and rituximab may be utilized intrathecally. Patients with refractory leptomeningeal carcinomatosis may benefit from a trial of intrathecal trastuzumab or rituximab; however, their use remains investigational, as more data and experience are necessary before intrathecal administration can be considered standard.

Intrathecal chemotherapy for treatment of leptomeningeal dissemination of metastatic tumours

Neoplastic meningitis consists of diffuse involvement of the leptomeninges by infiltrating cancer cells, and can be caused by systemic or primary CNS tumours, such as solid cancers or lymphoproliferative malignant disease. Neoplastic meningitis is characterised by multifocal neurological signs and symptoms. Thus, careful neurological examination is needed for diagnosis of secondary diffuse involvement. Survival of patients with neoplastic meningitis is short (3-4 months), although some patients have long-lasting remission. Because most patients with neoplastic meningitis have diffuse systemic disease, treatment is typically palliative. However, more aggressive treatments are available to low-risk patients, which could increase survival. Therefore, identification of low-risk patients is important. Intrathecal chemotherapy is currently the main treatment for patients with neoplastic meningitis, but optimum anticancer chemotherapy is being studied.

Rituximab: mechanism of action

Rituximab is a mainstay in the therapy for a broad variety of B-cell malignancies. Despite its undeniable therapeutic value, we still do not fully understand the mechanisms of action responsible for rituximab's anti-tumor effects. Direct signaling, complement-mediated cytotoxicity (CMC), and antibody-dependent cellular cytotoxicity (ADCC) all appear to play a role in rituximab efficacy. In vitro, animal model and clinical data addressing each of these mechanisms of action are reviewed, as are data speaking to the complexity of interactions between these mechanisms. Taken together, these data suggest different mechanisms are likely important in different scenarios. Study of the complex mechanisms of action that contribute to the clinical efficacy of rituximab have led to novel clinical trials including novel combinations, schedules, and generation of additional antibodies designed to have even greater effect. Such studies need to be accompanied by rigorous correlative analysis if we are to understand the importance of various mechanisms of action of rituximab and use that information to improve on what is already an indispensable component of therapy.

Primary central nervous system lymphoma: an update

PURPOSE OF REVIEW

The purpose of the present review is to present an overview of the recent findings in diagnostic procedures, treatment outcomes and biological advances in primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

Recent imaging techniques are helpful in the diagnosis of atypical presentations of PCNSL and are likely to represent useful tools for patient follow-up. Knowledge of the biology of PCNSL is still fragmentary, but an increasing amount of data support the biological specificity of this disease with the identification of specific molecular alterations in PCNSL and specific interactions of lymphoma cells with the CNS microenvironment. The origin of the malignant cell is still unknown. Improvement of the therapeutic results along with numerous phase II studies clearly highlight a few important issues that need to be unequivocally answered and stress the need for the development of multicentric comparative studies. Attempts to decrease treatment-related toxicity on the CNS without impacting the disease control are ongoing.

SUMMARY

The standard of care for PCNSL has definitively switched toward a curative objective. Considerable cooperative efforts are being made and will hopefully result in both a better understanding of the disease and significant therapeutic outcomes.

Bing-Neel syndrome: a case report and systematic review of clinical manifestations, diagnosis, and treatment options

BACKGROUND

Bing-Neel syndrome is an extremely rare neurologic complication of Waldenström macroglobulinemia (WM) that was first described in 1936. It is associated with central nervous system infiltration by neoplastic lymphoplasmacytoid and plasma cells with or without cerebrospinal fluid (CSF) hyperglobulinemia.

CASE REPORT

We report a case of a 69-year-old white man with a 10-year history of WM. He was diagnosed with Bing-Neel syndrome based on magnetic resonance imaging and pathology studies of CSF. In addition, a comprehensive review of the reported cases of Bing-Neel syndrome in the up-to-date English-language literature was performed.

RESULTS

Our patient underwent successful treatment with cranial radiation and intrathecal chemotherapy. He has been in clinical and pathologic remission for 3 years following the completion of his treatment. Based on our literature review, we also summarize and discuss clinical manifestations, diagnosis, and treatment options for Bing-Neel syndrome.

CONCLUSION

Bing-Neel syndrome is a rare and potentially treatable complication of WM. Patients with a history of WM presenting with neurologic symptoms should be evaluated for possible Bing-Neel syndrome. Cranial radiation therapy alone or in combination with intrathecal chemotherapy is more likely to achieve sustainable remission than intrathecal chemotherapy alone.

[Therapeutic management of central nervous system lymphomas in a single hematological institute]

Primary central nervous system lymphoma is defined as an extranodal lymphoma arising in the central nervous system in the absence of systemic disease. Because of their rare occurrence among lymphomas, optimal treatment could hardly be established.

AIMS

In this retrospective survey we analyzed the result of combined treatment (systemic and intrathecal chemotherapy followed by consolidation radiotherapy) in patients with primary or relapsed central nervous system lymphomas diagnosed and treated in our hematological department between 1998-2009.

PATIENTS AND METHODS

During this period (mean follow-up of 13.2 months) from 427 patients with newly diagnosed non-Hodgkin's lymphomas, 22 primary central nervous system lymphoma was diagnosed (5.15%, 16 cerebral and 6 spinal cord lymphoma cases). Significant male predominance (14:8) was registered with an age distribution of 34-77 years (mean = 60.7, median = 64 years). No patients were immunocompromised. All central nervous system lymphoma specimens taken with neurosurgical resection or stereotaxic biopsies were confirmed histopathologically. All cerebral lymphoma cases proved to be diffuse large B-cell of origin, while in epidural lymphomas low grade subtypes also occurred. Epidural lymphomas were treated with local radiotherapy (30-40 Gy), except for patients with follicular lymphomas getting rituximab-containing polychemotherapy (R + CHOP regimen) before irradiation. In cerebral lymphoma (every patients had supratentorial localization) the following combined therapy protocol was used: up to three courses of high dose methotrexate (HD MTX 3g/m 2 in a single dose for 4 hours lasting drop-infusion) were given at 4-week intervals, followed by leucovorin-rescue 24 hours after MTX infusion. Intrathecal combination of methotrexate, cytosin-arabinosid and dexamethasone was given three times after HD MTX infusion. In complete response after chemotherapy (evaluated by cranial MRI or CT, PET/CT), whole-brain irradiation was used in a total dose of 30 Gy. In case of partial response, boost irradiation for the tumor bed was also given. In relapse or resistant cases, salvage regimen was applied: HD MTX course combined with high dose cytosin-arabinosid (HD Ara-C) 3g/m 2 /dose b.i.d. over 4 h c.i., repeated in three cycles every four weeks.

RESULTS

Complete remission has been achieved in 9 patients with cerebral and in 4 patients with spinal cord lymphoma (13/22; 59.0%), however, one relapsed patient became resistant and later expired, despite salvage therapy. Primarily 9 patients were not evaluable for response: 5 received only one or two HD MTX because of side effects, 4 patients died due to progression of the disease. Mean of the overall survival (OS) in cerebral lymphoma was 19.5 (3-46, median of 10) months, in epidural group 14.1 (2-76, median of 5) months, whilst mean time to progression (TTP) was 4.5 (2-6.5, median of 4 months). The 2-year survival for all patients was 50%. Acute toxicity of chemotherapy was usually hematological, moreover, in 8 patients impaired renal function and sepsis developed. No serious adverse effect of radiotherapy could be detected.

CONCLUSION

In primary central nervous system lymphoma, basic treatment HD methotrexate together with intrathecal combination of methotrexate + cytosin-arabinosid + dexamethasone followed by whole-brain irradiation of at least 30 Gy could produce a medium response rate in our study. In case of relapse or progression, other salvage regimens containing HD Ara-C alternating with HD MTX could reduce the treatment failure, as well. After therapy PET/CT was negative in five patients with prolonged disease-free survival.

Diffusion-weighted MR imaging derived apparent diffusion coefficient is predictive of clinical outcome in primary central nervous system lymphoma

BACKGROUND AND PURPOSE

There is evidence that increased tumor cellular density within diagnostic specimens of primary central nervous system lymphoma (PCNSL) may have significant prognostic implications. Because cellular density may influence measurements of apparent diffusion coefficient (ADC) by using diffusion-weighted MR imaging (DWI), we hypothesized that ADC measured from contrast-enhancing regions might correlate with clinical outcome in patients with PCNSL.

MATERIALS AND METHODS

PCNSL tumors from 18 immunocompetent patients, treated uniformly with methotrexate-based chemotherapy, were studied with pretherapeutic DWI. Enhancing lesions were diagnosed by pathologic analysis as high-grade B-cell lymphomas. Regions of interest were placed around all enhancing lesions allowing calculation of mean, 25th percentile (ADC(25%)), and minimum ADC values. Histopathologic tumor cellularity was quantitatively measured in all patients. High and low ADC groups were stratified by the median ADC value of the cohort. The Welch t test assessed differences between groups. The Pearson correlation examined relationships between ADC measurements and tumor cellular density. Single and multivariable survival analysis was performed.

RESULTS

We detected significant intra- and intertumor heterogeneity in ADC measurements. An inverse correlation between cellular density and ADC measurements was observed (P < .05). ADC(25%) measurements less than the median value of 692 (low ADC group) were associated with significantly shorter progression-free and overall survival. Patients with improved clinical outcome were noted to exhibit a significant decrease in ADC measurements following high-dose methotrexate chemotherapy.

CONCLUSIONS

Our study provides evidence that ADC measurements within contrast-enhancing regions of PCNSL tumors may provide noninvasive insight into clinical outcome.