Encephalopathy in a Patient After Long-Term Treatment With Thalidomide

The double-edged sword: Neurotoxicity of chemotherapy

The number of available therapies for hematologic malignancies continues to grow at a rapid pace. Unfortunately, many of these treatments carry both central and peripheral nervous system toxicities, potentially limiting a patient's ability to tolerate a full course of treatment. Neurotoxicity with chemotherapy is common and second only to myelosuppression as a reason to limit dosing. This review addresses the neurotoxicity of newly available therapeutic agents including brentuximab vedotin and blinatumomab as well as classic ones such as methotrexate, vinca alkaloids and platinums. Although peripheral neuropathy is common with many drugs, other complications such as seizures and encephalopathy may require more immediate attention. Rapid recognition of adverse neurologic effects may lead to earlier treatment and appropriate adjustment of dosing regimens. In addition, knowledge of common toxicities may help differentiate chemotherapy-related symptoms from actual progression of cancer into the CNS.

[Central nervous system complications in patients undergoing cytotoxic chemotherapy and targeted therapies]

Anti-cancer treatments (cytotoxic chemotherapies, targeted therapies and hormonotherapies) are known to induce early and delayed neurological toxicities. Acute encephalopathies and posterior reversible encephalopathies are better known and described, physiopathological hypotheses are emerging. It is difficult to discriminate what drug is causing the symptoms in patients treated with multiple cytotoxic drugs. Methotrexate and ifosfamide are responsible for acute encephalopathies. L-asparaginase and methotrexate or targeted therapies may induce cerebrovascular complications. As life expectancy increases and more complex regimen including innovative targeted therapies are developed, new toxicity profiles can be expected. To be able to provide an early diagnosis, prevention, and treatment (when existing) of these pathologies remains a tremendous challenge that would allow a good quality of life with social and professional life after their cancer is cured.

Prospective evaluation of quality of life and neurocognitive effects in patients with multiple brain metastases receiving whole-brain radiotherapy with or without thalidomide on Radiation Therapy Oncology Group (RTOG) trial 0118

PURPOSE

Radiation Therapy Oncology Group (RTOG) 0118 randomized patients with multiple brain metastases to whole-brain radiotherapy (WBRT) +/- thalidomide. This secondary analysis of 156 patients examined neurocognitive and quality of life (QOL) outcomes.

METHODS AND MATERIALS

Quality of life was determined with the Spitzer Quality of Life Index (SQLI). The Folstein Mini-Mental Status Exam (MMSE) assessed neurocognitive function. SQLI and MMSE were administered at baseline and at 2-month intervals. MMSE was scored with a threshold value associated with neurocognitive functioning (absolute cutoff level of 23) and with the use of corrections for age and educational level.

RESULTS

Baseline SQLI predicted survival. Patients with SQLI of 7-10 vs. <7 had median survival time (MST) of 4.8 vs. 3.1 months, p = 0.05. Both arms showed steady neurocognitive declines, but SQLI scores remained stable. Higher levels of neurocognitive decline were observed with age and education-level corrections. Of patients considered baseline age/educational level neurocognitive failures, 32% died of intracranial progression.

CONCLUSIONS

Quality of life and neuropsychological testing can be prospectively administered on a Phase III cooperative group trial. The MMSE should be evaluated with adjustments for age and educational level. Baseline SQLI is predictive of survival. Despite neurocognitive declines, QOL remained stable during treatment and follow-up. Poor neurocognitive function may predict clinical deterioration. Lack of an untreated control arm makes it difficult to determine the contribution of the respective interventions (i.e., WBRT, thalidomide) to neurocognitive decline. The RTOG has developed a trial to study the role of preventative strategies aimed at forestalling neurocognitive decline in this population.