White matter changes in primary central nervous system lymphoma patients treated with high-dose methotrexate with or without rituximab

Neurological complications in oncology and their monitoring and management in clinical practice: a narrative review

IMPORTANCE

New anti-tumor treatments, such as immune checkpoint inhibitors and CAR T-cell therapy, are associated with an increasing number of neurological issues linked to tumors not arising from nervous system such as neurological and neuropsychological side effects that can significantly impair quality of life in the short or long term. The science of pathomechanisms, therapeutic approaches, and preventive measures is still in its early stages, and the progress is hampered by the lack of studied connection between neurological and oncological disciplines.

OBJECTIVES

This work aimed to provide an overview of the questions raised in the field of clinical neuroscience that concern the outcomes of oncological diseases and their treatment. Furthermore, we give an outline of how a collaborative approach between neurology and oncology, with the implementation of neuroscience techniques including up-to-date diagnostics and therapy, can help to improve the quality of oncological patients' lives.

EVIDENCE REVIEW

The covered areas of investigation in the evaluated articles primarily encompassed the review of known neurological complications of oncological diseases caused by neurotoxic mechanisms of performed therapies or those linked to concurrent pathological conditions. Similarly, the methods of their diagnostics were assessed.

FINDINGS

Our literature review of 65 articles, including clinical trials, cohort studies, reviews, and theoretically based in vitro studies published between 1998 and 2023, outlines the broad spectrum of neurological complications primarily associated with malignant diseases and the anti-tumor therapies employed. Notably, immune-mediated complications, whose incidence is increasing due to the expanding use of new immunotherapies, require early detection and targeted treatment to prevent severe progression. In this context, neurological complications mediated by immune checkpoint inhibitors are often associated with significant impairments and high mortality, necessitating specialist consultation for early detection and differentiation from other phenotypically similar syndromes. Current data on the pathophysiology of these neurological complications are not reliable due to the limited number of studies. Moreover, there is a lack of evidence regarding the appropriate oncological approach in the event of therapy-related complications. Initial study results suggest that the establishment of interdisciplinary treatment interfaces for the management of oncology patients could improve the safety of these therapies and enhance the patients' quality of life.

CONCLUSIONS AND RELEVANCE

The accumulated knowledge on neurotoxicity caused by oncological diseases shows that the challenges in diagnosing and managing this condition are expanding in tandem with the growing array of therapies being employed. Therefore, it requires interdisciplinary approach with the introduction of new facilities enabling more personalized patient care.

Clinical relevance of brain MRI changes in primary central nervous system lymphoma after high-dose-chemotherapy and autologous stem cell transplantation

Primary central nervous system lymphoma (PCNSL) is a potentially curable disease, but affected patients often struggle in everyday life due to disease- and therapy-associated sequelae. High-dose chemotherapy followed by autologous stem cell transplantation (HDC/ASCT) is the standard consolidation therapy, replacing whole brain radiation therapy (WBRT) amongst others due to less long-term cognitive decline. Nevertheless, white matter lesions (WML) are common findings in brain MRI after HDC/ASCT, but their clinical significance remains underexplored. Here, we correlate WML and brain atrophy with neuropsychological and quality-of-life evaluations collected post-treatment. We found that a significant part of PNCSL long-term survivors develop a high WML burden after HDC/ASCT, but we fail to associate them with specific patient or therapy characteristics. Intriguingly, even a high WML burden does not seem to affect QoL, basic neurocognition testing or performance status negatively. These results contrast findings in previous neuroimaging studies on healthy and cancer patients.

Association of MTHFR Polymorphisms With Leukoencephalopathy Risk in Patients With Primary CNS Lymphoma Treated With Methotrexate-Based Regimens

OBJECTIVES

The folate antagonist high-dose methotrexate (HD-MTX) is integral to induction chemotherapy for primary CNS lymphoma (PCNSL); however, it can be associated with leukoencephalopathy. Methylenetetrahydrofolate reductase (MTHFR) is involved in intracellular folate depletion. We assessed whether MTHFR polymorphisms affect the risk of leukoencephalopathy.

METHODS

We retrospectively searched our database at the Massachusetts General Hospital for newly diagnosed PCNSL treated with HD-MTX (without radiotherapy nor intrathecal chemotherapy).

RESULTS

Among 68 patients with PCNSL, MTHFR polymorphisms were found in 60 individuals (88.2%) including a 677C→T genotype, a 1298A→C genotype, or a combined 677C→T/1298A→C genotype. Neither MTX clearance nor response to induction therapy was affected by specific genotypes, and complete response was achieved in 72.1% of patients by HD-MTX-based induction. However, the 1298A→C genotype was associated with increased frequency and severity of leukoencephalopathy over time (odds ratio 4.0, CI 1.5-11.4). Such genotype predicted treatment-induced leukoencephalopathy with a sensitivity of 71.0% and a specificity of 62.2% (area under the curve 0.67, CI 0.5-0.8; p = 0.019). While progression-free survival did not differ in genotype-based subgroups, overall survival was lower for the 1298A→C genotype.

DISCUSSION

The MTHFR 1298A→C genotype may serve to identify patients with PCNSL at elevated risk of HD-MTX-induced leukoencephalopathy. This seems to translate into reduced survival, potentially due to decreased functional status.

Neurocognitive functioning and radiologic changes in primary CNS lymphoma patients: results from the HOVON 105/ALLG NHL 24 randomized controlled trial

BACKGROUND

To analyze the effect of treatment on neurocognitive functioning and the association of neurocognition with radiological abnormalities in primary central nervous system lymphoma (PCNSL).

METHODS

One hundred and ninety-nine patients from a phase III trial (HOVON 105/ALLG NHL 24), randomized to standard chemotherapy with or without rituximab, followed in patients ≤60 years old by 30-Gy whole-brain radiotherapy (WBRT), were asked to participate in a neuropsychological evaluation before and during treatment, and up to 2 years posttreatment. Scores were transformed into a standardized z-score; clinically relevant changes were defined as a change in z-score of ≥1 SD. The effect of WBRT was analyzed in irradiated patients. All MRIs were centrally assessed for white matter abnormalities and cerebral atrophy, and their relation with neurocognitive scores over time in each domain was calculated.

RESULTS

125/199 patients consented to neurocognitive evaluation. Statistically significant improvements in neurocognition were seen in all domains. A clinically relevant improvement was seen only in the motor speed domain, without differences between the arms. In the follow-up of irradiated patients (n = 43), no change was observed in any domain score, compared to after WBRT. Small but significant inverse correlations were found between neurocognitive scores over time and changes in white matter abnormalities (regression coefficients: -0.048 to -0.347) and cerebral atrophy (-0.212 to -1.774).

CONCLUSIONS

Addition of rituximab to standard treatment in PCNSL patients did not impact neurocognitive functioning up to 2 years posttreatment, nor did treatment with 30-Gy WBRT in patients ≤60 years old. Increased white matter abnormalities and brain atrophy showed weak associations with neurocognition.

The clinical heterogeneity of entirely nonenhancing CNS lymphoma: a case series

CNS lymphoma often presents with atypical imaging characteristics leading to delay in diagnosis and initiation of treatment. Among the most rarely reported of these is entirely nonenhancing CNS lymphoma, which is estimated at an incidence of about 1%. Here, we present three cases of nonenhancing CNS lymphoma in immune competent patients at both initial presentation and recurrence and in primary as well as secondary CNS lymphoma. Diffusion- and perfusion-weighted imaging was found helpful in diagnosis in some cases.

Neurotoxicity of Cancer Therapies

PURPOSE OF REVIEW

This article reviews neurologic complications associated with chemotherapy, radiation therapy, antiangiogenic therapy, and immunotherapy.

RECENT FINDINGS

Cancer therapies can cause a wide range of neurologic adverse effects and may result in significant patient morbidity and mortality. Although some treatment-associated neurologic complications manifest acutely and are often reversible and transient, others occur with delayed onset, can be progressive, and are uniquely challenging to patient management. With an increase in multimodality and combination therapies, including targeted therapies and immunotherapies, and prolonged patient survival, novel and unique patterns of neurologic complications have emerged.

SUMMARY

Both conventional and novel cancer therapies can adversely affect the nervous system, thereby producing a wide range of neurologic complications. Increased awareness among neurologists and early recognition of cancer therapy-induced neurotoxic syndromes is critically important to minimize patient morbidity, prevent permanent injury, and improve patient outcomes.

The Role of Rituximab in Primary Central Nervous System Lymphoma

Purpose of Review

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

Recent Findings

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

Summary

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