Advances in treatments of patients with classical and emergent neurological toxicities of anticancer agents.

The neurotoxicity associated to the anticancer treatments has received a growing body of interest in the recent years. The development of innovating therapies over the last 20years has led to the emergence of new toxicities. Their diagnosis and management can be challenging in the clinical practice and further research is warranted to improve the understanding of their pathogenic mechanisms. Conventional treatments as radiation therapy and chemotherapy are associated to well-known and under exploration emerging central nervous system (CNS) and peripheral nervous system (PNS) toxicities. The identification of the risk factors and a better understanding of their pathogeny through a "bench to bedside and back again" approach, are the first steps towards the development of toxicity mitigation strategies. New imaging techniques and biological explorations are invaluable for their diagnosis. Immunotherapies have changed the cancer treatment paradigm from tumor cell centered to immune modulation towards an efficient anticancer immune response. The use of the immune checkpoints inhibitors (ICI) and CAR-T cells (chimeric antigen receptor) lead to an increase in the incidence of immune-mediated toxicities and new challenges in the neurological patient's management. The neurological ICI related adverse events (n-irAE) are rare but potentially severe and may present with both CNS and PNS involvement. The most frequent and well characterized, from a clinical and biological standpoint, are the PNS phenotypes: myositis and polyradiculoneuropathy, but the knowledge on CNS phenotypes and their treatments is expanding. The n-irAE management requires a good balance between dampening the autoimmune toxicity without impairing the anticancer immunity. The adoptive cell therapies as CAR-T cells, a promising anticancer strategy, trigger cellular activation and massive production of proinflammatory cytokines inducing frequent and sometime severe toxicity known as cytokine release syndrome and immune effector cell-associated neurologic syndrome. Their management requires a close partnership between oncologist-hematologists, neurologists, and intensivists. The oncological patient's management requires a multidisciplinary clinical team (oncologist, neurologist and paramedical) as well as a research team leading towards a better understanding and a better management of the neurological toxicities.

Neurological side effects of radiation therapy.

Radiation therapy (RT) is one of the main treatments administered to patients with cancer. The development of technology has improved RT accuracy by allowing more precise delivery of high doses to the target volumes with reduced exposure of healthy tissue. Life expectancy has increased due to these therapeutic advancements and the patients' quality of life remains a major concern. The adverse events related to RT are quite various and most likely will impair essential neurological functions, e.g. cognitive status. This literature review aims to describe the physiopathological processes, the neurological symptoms as well as the local modifications observed in magnetic resonance imaging following RT. The specific therapeutic options and preventive actions will also be discussed.

Autoimmune cerebellar hypermetabolism: Report of three cases and literature overview.

We report three cases of vermian cerebellar hypermetabolism in patients with autoimmune encephalitis. One of our patients was positive for anti-Ma2 antibodies and one for anti-Zic4 antibodies while the remaining patient did not present any known antibodies. The seronegative patient deteriorated after immune checkpoint inhibitor treatment for a pulmonary adenocarcinoma and improved with immunosuppressive drugs, which is in favour of an underlying autoimmune mechanism. They all presented with subacute neurological symptoms. Brain magnetic resonance imaging was normal except in one patient, where hyperintensities were present on FLAIR sequence around the third ventricle and the cerebral aqueduct. 18F-FDG brain positron emission tomography with computed tomography (18F-FDG PET-CT) demonstrated an unusual vermian cerebellar hypermetabolism in the three cases. While cerebellar hypermetabolism on 18F-FDG PET-CT has been described in various neurological diseases, such vermian - and more broadly cerebellar - hypermetabolism was seldom described in previous studies on autoimmune encephalitis. When differential diagnoses have been ruled out, this pattern may be of interest for the positive diagnosis of autoimmune encephalitis in difficult diagnostic cases.

Comparison of Lewis-Sumner syndrome with chronic inflammatory demyelinating polyradiculoneuropathy patients in a tertiary care centre.

BACKGROUND AND PURPOSE: Whether the Lewis-Sumner syndrome (L-SS) is a distinct entity from other types of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP-ot) remains controversial. METHOD: The clinical/electrophysiological characteristics and long-term outcomes of 45 L-SS and 35 CIDP-ot patients were retrospectively compared. RESULTS: The CIDP-ot group was composed of 11 patients with a typical CIDP, 17 with a pure sensory form, four with a distal form and three with a pure motor form. In the L-SS group, asymmetric (P < 0.001) and monomelic involvement (P = 0.04) of the upper limbs (P < 0.001) was significantly more frequent; paucisymptomatic forms (Overall Neuropathy Limitations Scale ≤ 1) were less frequent (P < 0.001); electroneuromyography showed that conduction block in intermediate nerve segments was the main demyelinating feature, with frequent F-wave abnormalities on nerves without conduction block (44%). Long-term prognosis was globally poorer in the L-SS group with more frequent aggravation during treatment (P = 0.02), less frequent treatment withdrawal (P = 0.03) and longer time to achieve successful withdrawal (39 vs. 15 months). CONCLUSIONS: Our study suggests that L-SS patients have a less favourable therapeutic response rate and long-term outcomes. Rapid differentiation of L-SS from other forms of CIDP is important in order to anticipate a more complicated disease course management, with from one side the inefficacy or even harmfulness of corticosteroids and from the other side a difficult weaning procedure. A prospective study is necessary to confirm these results.

The cerebrospinal fluid CD4/CD8 ratio and interleukin-6 and -10 levels in neurosarcoidosis: a multicenter, pragmatic, comparative study.

BACKGROUND AND PURPOSE: Neurosarcoidosis is a rare inflammatory disorder of unknown cause. The aim of this study was to evaluate the value of T/B lymphocyte population counts and the concentrations of the cytokines interleukin (IL) 6 and IL-10 in the cerebrospinal fluid (CSF) of neurosarcoidosis patients. METHODS: A retrospective study CSF biomarkers was conducted in patients with neurosarcoidosis who underwent CSF analysis between 2012 and 2017 as well as various control populations. RESULTS: Forty-three patients with neurosarcoidosis, 14 with multiple sclerosis (MS) and 48 with other inflammatory disorders were analyzed. The CSF IL-6 levels were higher in sarcoidosis patients than in MS patients (median 8 vs. 3 pg/ml, P = 0.006). The CSF CD4/CD8 ratio was higher in sarcoidosis patients than in MS patients and in patients with other inflammatory disorders (median 3.18 vs. 2.36 and 2.10, respectively, P = 0.008). The CSF IL-6 level was higher in patients with active neurosarcoidosis than in non-active neurosarcoidosis patients (median 13 vs. 3 pg/ml, P = 0.0005). In patients with neurosarcoidosis, a CSF IL-6 concentration >50 pg/ml was associated with a higher risk of relapse or progression-free survival (hazard ratio 3.60; 95% confidence interval 1.78-23.14). A refractory neurosarcoidosis patient was treated with an anti-IL-6 monoclonal antibody that produced a complete neurological response. CONCLUSIONS: The CSF CD4/CD8 ratio and IL-6 concentration are increased in neurosarcoidosis compared to MS and other inflammatory disorders. A CSF IL-6 concentration >50 pg/ml is associated with relapse or progression of neurosarcoidosis. IL-10 levels may be elevated in neurosarcoidosis.

Antineoplastic agents exacerbating Charcot Marie Tooth disease: red flags to avoid permanent disability.

BACKGROUND: Charcot Marie Tooth (CMT) disease is the most common form of hereditary neuropathy. Due to the high prevalence of mild and undiagnosed forms, patients with CMT disease may be exposed to severe neurotoxicity following the administration of neurotoxic chemotherapies. The aim of this report is to alert oncologists to the potential to precipitate severe irreversible peripheral neuropathies when administering neurotoxic compounds to undiagnosed CMT patients. MATERIAL AND METHODS: A retrospective research in the OncoNeuroTox database was performed (2010-2016), searching for patients with the diagnosis of chemotherapy-induced peripheral neuropathy (CIPN) and CMT disease. A comprehensive literature review for previously published cases was performed using the Pubmed and Cochrane databases (1972-2017). RESULTS: Among 428 patients with CIPN, we identified eight patients with concomitant CMT disease. Seven patients out of the eight had no previous diagnosis of CMT disease, although accurate familial history disclosed mild signs of peripheral neuropathy in five cases. Patients themselves had minor stigmata of long-standing peripheral damage. Patients received chemotherapy regimens based on vinca alkaloids, taxanes or a combination of vinca alkaloids and platinum compounds. In two cases, cumulative doses were below or equal to the expected neurotoxic threshold. Following chemotherapy administration, patients developed severe length-dependent sensory-motor deficits. Despite early drug discontinuation, most patients remained severely disabled. CONCLUSION: A brief checklist to disclose long-standing signs of peripheral neuropathy could be helpful to detect patients with undiagnosed hereditary neuropathies who could be at risk of developing severe irreversible neurotoxicity following the administration of neurotoxic agents.

SMART syndrome: Classic transient symptoms leading to an unusual unfavorable outcome.

BACKGROUND: Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare complication of cerebral radiation therapy that usually presents>10 years after treatment as reversible paroxysmal episodes of neurological dysfunction associated with headaches. CASES: We report here on two cases of SMART syndrome in long-term survivors of high-grade glioma for whom neuropathological data were available. The course of the disease was unfavorable. Although the clinico-radiological picture of SMART syndrome clearly differs from classic cerebral radionecrosis, the gross neuropathological lesions observed in our two patients appeared to be similar to those described in focal radionecrosis. CONCLUSION: SMART syndrome may progress from a benign reversible form to a severe and eventually irreversible form. This severe course may also be confused with tumor progression, and lead to permanent disability and inadequate antitumor treatment. Clinicians should be aware of this latter atypical presentation.

Posterior reversible encephalopathy syndrome (PRES) and hypomagnesemia: A frequent association?

Posterior reversible encephalopathy syndrome (PRES) is a serious neurological condition encountered in various medical fields. Pathophysiological factor(s) common to PRES cases of apparently unrelated etiologies are yet to be found. Based on the hypothesis that hypomagnesemia might participate in the cascade leading to PRES, our study sought to verify whether hypomagnesemia is frequently associated with PRES regardless of etiology. From a retrospective study of a cohort of 57 patients presenting with PRES of different etiologies, presented here are the findings of 19 patients with available serum magnesium levels (SMLs) during PRES. In the acute phase of PRES, hypomagnesemia was present in all 19 patients in spite of differences in etiology (including immunosuppressive drugs, hypertensive encephalopathy, eclampsia, systemic lupus erythematosus, iatrogenic etiology and unknown). SMLs were within normal ranges prior to PRES and below normal ranges during the first 48h of PRES, with a significant decrease in SMLs during the acute phase. In this retrospective study, constant hypomagnesemia was observed during the acute phase of PRES regardless of its etiology. These results now require larger studies to assess the particular importance of acute hypomagnesemia in PRES and especially the possible need to treat PRES with magnesium sulfate.

Physician-assessed and patient-reported outcome measures in chemotherapy-induced sensory peripheral neurotoxicity: two sides of the same coin.

BACKGROUND: The different perception and assessment of chemotherapy-induced peripheral neurotoxicity (CIPN) between healthcare providers and patients has not yet been fully addressed, although these two approaches might eventually lead to inconsistent, possibly conflicting interpretation, especially regarding sensory impairment. PATIENTS AND METHODS: A cohort of 281 subjects with stable CIPN was evaluated with the National Cancer Institute-Common Toxicity Criteria (NCI-CTC v. 2.0) sensory scale, the clinical Total Neuropathy Score (TNSc©), the modified Inflammatory Neuropathy Cause and Treatment (INCAT) sensory sumscore (mISS) and the European Organization for Research and Treatment of Cancer CIPN specific self-report questionnaire (EORTC QOL-CIPN20). RESULTS: Patients' probability estimates showed that the EORTC QLQ-CIPN20 sensory score was overall more highly related to the NCI-CTC sensory score. However, the vibration perception item of the TNSc had a higher probability to be scored 0 for EORTC QLQ-CIPN20 scores lower than 35, as vibration score 2 for EORTC QLQ-CIPN20 scores between 35 and 50 and as grade 3 or 4 for EORTC QLQ-CIPN20 scores higher than 50. The linear models showed a significant trend between each mISS item and increasing EORTC QLQ-CIPN20 sensory scores. CONCLUSION: None of the clinical items had a perfect relationship with patients' perception, and most of the discrepancies stood in the intermediate levels of CIPN severity. Our data indicate that to achieve a comprehensive knowledge of CIPN including a reliable assessment of both the severity and the quality of CIPN-related sensory impairment, clinical and PRO measures should be always combined.

Seronegative paraneoplastic cerebellar degeneration: the PNS Euronetwork experience.

BACKGROUND AND PURPOSE: To describe the characteristics of patients presenting a paraneoplastic cerebellar degeneration without classical onconeural antibodies (seronegative PCD). METHODS: Thirty-nine seronegative PCD patients from the Paraneoplastic Neurological Syndrome Euronetwork were retrospectively analyzed and compared with 180 patients with PCD associated with classical onconeural antibodies (seropositive PCD). RESULTS: No patient had anti-CASPR2 or anti-mGluR1 antibodies. No significant difference between the clinical characteristics of seronegative and seropositive PCD patients was observed. Yet the frequency of associated tumors was different. Lymphoma was more frequent in seronegative than in seropositive women (24% vs. 2%, P = 0.002) whilst gynecological cancer were less frequent (38% vs. 74%, P = 0.002). In comparison with seropositive men, seronegative men more frequently had a non-small-cell lung cancer (27% vs. 6%, P = 0.08) or a genitourinary cancer (22% vs. 0%, P = 0.04) but less frequently a small-cell lung cancer (23% vs. 74%, P = 0.002). Seronegative and seropositive PCD patients with similar tumors had a similar overall survival. CONCLUSION: The clinical characteristics of seronegative and seropositive PCD are similar but the spectrum of associated tumors is different. The immunological scenario of seronegative PCD seems to be different from that of limbic encephalitis with only few patients harboring anti-neuropile antibodies.

Solitary tuberculous brain lesions: 24 new cases and a review of the literature.

A solitary tuberculous brain lesion (STBL) can be difficult to distinguish from a glioma, metastasis or other infectious disease, especially from a pyogenic brain abscess. We analyzed the clinical characteristics, diagnostic procedures and outcomes of 24 patients with STBL diagnosed in three centers from France, India and Mexico. We also reviewed 92 STBL cases previously reported in the literature. General symptoms were found in 54% of our patients, including enlarged lymph nodes in 20%. Cerebrospinal fluid was typically abnormal, with lymphocytic pleocytosis and a high protein level. The lung CT scan was abnormal in 56% of patients, showing lymphadenopathy or pachipleuritis. Brain MRI or CT was always abnormal, showing contrast-enhanced lesions. Typically, MRI abnormalities were hypointense on T1-weighted sequences, while T2-weighted sequences showed both a peripheral hypersignal and a central hyposignal. The diagnosis was documented microbiologically or supported histologically in 71% of cases. Clinical outcome was good in 83% of cases.

Prognosis of glioblastoma patients improves significantly over time interrogating historical controls.

BACKGROUND: Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time. METHODS: To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018). RESULTS: Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001). CONCLUSION: This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

The chemotherapy-induced peripheral neuropathy outcome measures standardization study: from consensus to the first validity and reliability findings.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and dose-limiting complication of cancer treatment. Thus far, the impact of CIPN has not been studied in a systematic clinimetric manner. The objective of the study was to select outcome measures for CIPN evaluation and to establish their validity and reproducibility in a cross-sectional multicenter study. PATIENTS AND METHODS: After literature review and a consensus meeting among experts, face/content validity were obtained for the following selected scales: the National Cancer Institute-Common Toxicity Criteria (NCI-CTC), the Total Neuropathy Score clinical version (TNSc), the modified Inflammatory Neuropathy Cause and Treatment (INCAT) group sensory sumscore (mISS), the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, and CIPN20 quality-of-life measures. A total of 281 patients with stable CIPN were examined. Validity (correlation) and reliability studies were carried out. RESULTS: Good inter-/intra-observer scores were obtained for the TNSc, mISS, and NCI-CTC sensory/motor subscales. Test-retest values were also good for the EORTC QLQ-C30 and CIPN20. Acceptable validity scores were obtained through the correlation among the measures. CONCLUSION: Good validity and reliability scores were demonstrated for the set of selected impairment and quality-of-life outcome measures in CIPN. Future studies are planned to investigate the responsiveness aspects of these measures.

Ongoing and prolonged response in adult low-grade gliomas treated with radiotherapy.

The aim of the present study was to evaluate the impact of first-line radiotherapy on low-grade gliomas (LGGs) growth kinetics. The mean tumor diameter (MTD) of 39 LGGs was retrospectively measured on serial magnetic resonance images before (n = 16) and after radiotherapy onset (n = 39). After radiotherapy, a decrease of the MTD was observed in 37 patients. Median duration of the MTD decrease was 1.9 years (range 0-8.1 years). According to RANO criteria, the rates of partial and minor responses were 15 and 28 % at the first evaluation after radiotherapy and 36 and 34 % at the time of maximal MTD decrease. The presence of a 1p19q codeletion and the absence of p53 expression were associated with longer durations of MTD decrease (5.3 vs 1 years, p = 0.02 and 2.4 vs 1.8 years, p = 0.05, respectively) while no association was observed between IDH1-R132H expression and duration of MTD decrease. In most patients, MTD decrease after radiotherapy occurred in two phases: an initial phase of rapid MTD decrease followed by a second phase of slower MTD decrease. Patients with a high rate of MTD decrease during the initial phase (>7 mm/year) had both a shorter duration of response (1.9 vs 5.3 years, p = 0.003) and a shorter overall survival (5.5 vs 11.6 years, p = 0.0004). LGGs commonly display a prolonged and ongoing volume decrease after radiotherapy. However, patients who respond rapidly should be carefully monitored because they are at a higher risk of rapid progression.

[Radiation-induced neuropathies: collateral damage of improved cancer prognosis]. / Neuropathies post-radiques: un dommage collatéral chez les patients cancéreux long-survivants.

INTRODUCTION: Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. STATE OF THE ART: Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. PERSPECTIVES AND CONCLUSION: The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and inflammation. A phase III trial evaluating the association of pentoxifylline, tocopherol and clodronate (PENTOCLO, NCT01291433) in radiation-induced neuropathies is now recruiting.