Cisplatin neuropathy: clinical course and neurophysiological findings

Abnormal quantitative sudomotor axon reflex test results in patients with tinnitus as a possible indicator of small fiber neuropathy

A few cases of small fiber neuropathy (SFN) and tinnitus (TN) associated with coronavirus disease 2019 have been reported. However, the relationship between SFN and TN has not been studied. This study investigated a possible relationship between SFN and patients with TN (PwTNs) using autonomic function tests (AFTs) including quantitative sudomotor axon reflex tests (QSART). We performed QSARTs and other AFTs such as the Sympathetic skin response (SSR), Valsalva ratio (VR), and heart rate variability (HRV). The QSART results, obtained at seven hospitals using same protocols, were compared between PwTNs and healthy controls. We confirmed the abnormalities in SSR, VR, and HRV in PwTNs, although those parasympathetic AFTs were not performed in healthy controls. Additionally, we checked Tinnitus handicap inventory (THI) scores for PwTNs and ~50% of PwTNs had low-grade disability, whereas 9.3% had high-grade disability. Data from 57 PwTNs and 122 healthy controls were analyzed. The sweat volumes of QSART in the older age group tended to be higher in the PwTNs than in age-matched healthy controls, and significant differences between the PwTN and control groups were observed in the feet in both sexes (p < 0.001) and in the arms in women (p = 0.013). In the younger age group, the sweat volumes in the feet of men were higher in PwTNs than in healthy controls (p = 0.017). No association was observed between THI and QSART scores. In this study, the sweat volumes in QSARTs were higher in PwTNs than in healthy controls. However, abnormal SSR, HRV, and VR results were not commonly observed in PwTNs. Although the results should be interpreted with caution because of limitations in study, PwTNs might also have SFN apart from dysautonomia. This is the first study to perform QSART with other parasympathetic AFTs in PwTNs. However, larger and more rigorously controlled studies will be needed to reveal the relationship between SFN and TN in the future.

A Case of Radiation-Induced Brachial Plexopathy Below the Tolerance Dose

This case report details a rare instance of radiation-induced brachial plexopathy (RIBP) occurring below the typical tolerance dose in a 55-year-old woman following chemoradiotherapy for apical non-small cell lung carcinoma. Despite receiving a radiation dose considered safe (47-48 Gray in 25 fractions), she developed sensory abnormalities and motor weakness in the right upper limb. The diagnostic distinction between RIBP and tumor recurrence was achieved using MRI, which showed characteristic features of radiation-induced damage. The patient's medical history included smoking and rheumatoid arthritis, highlighting the role of patient-specific factors in the development of RIBP. The case underscores the importance of recognizing RIBP as a potential diagnosis in patients with new-onset brachial plexopathy post-radiation therapy, even when radiation exposure is within conventional safety limits. This report contributes to the literature by demonstrating that RIBP can occur at lower-than-expected radiation doses, especially in the presence of contributing factors like neurotoxic chemotherapy and individual patient risks. It emphasizes the need for careful assessment and management in such cases to distinguish between RIBP and cancer recurrence.

Neutrophil extracellular traps as a unique target in the treatment of chemotherapy-induced peripheral neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a severe dose-limiting side effect of chemotherapy and remains a huge clinical challenge. Here, we explore the role of microcirculation hypoxia induced by neutrophil extracellular traps (NETs) in the development of CIPN and look for potential treatment.

METHODS

The expression of NETs in plasma and dorsal root ganglion (DRG) are examined by ELISA, IHC, IF and Western blotting. IVIS Spectrum imaging and Laser Doppler Flow Metry are applied to explore the microcirculation hypoxia induced by NETs in the development of CIPN. Stroke Homing peptide (SHp)-guided deoxyribonuclease 1 (DNase1) is used to degrade NETs.

FINDINGS

The level of NETs in patients received chemotherapy increases significantly. And NETs accumulate in the DRG and limbs in CIPN mice. It leads to disturbed microcirculation and ischemic status in limbs and sciatic nerves treated with oxaliplatin (L-OHP). Furthermore, targeting NETs with DNase1 significantly reduces the chemotherapy-induced mechanical hyperalgesia. The pharmacological or genetic inhibition on myeloperoxidase (MPO) or peptidyl arginine deiminase-4 (PAD4) dramatically improves microcirculation disturbance caused by L-OHP and prevents the development of CIPN in mice.

INTERPRETATION

In addition to uncovering the role of NETs as a key element in the development of CIPN, our finding provides a potential therapeutic strategy that targeted degradation of NETs by SHp-guided DNase1 could be an effective treatment for CIPN.

FUNDING

This study was funded by the National Natural Science Foundation of China81870870, 81971047, 81773798, 82271252; Natural Science Foundation of Jiangsu ProvinceBK20191253; Major Project of "Science and Technology Innovation Fund" of Nanjing Medical University2017NJMUCX004; Key R&D Program (Social Development) Project of Jiangsu ProvinceBE2019732; Nanjing Special Fund for Health Science and Technology DevelopmentYKK19170.

Revisiting the Anti-Cancer Toxicity of Clinically Approved Platinating Derivatives

Cisplatin (CDDP), carboplatin (CP), and oxaliplatin (OXP) are three platinating agents clinically approved worldwide for use against a variety of cancers. They are canonically known as DNA damage inducers; however, that is only one of their mechanisms of cytotoxicity. CDDP mediates its effects through DNA damage-induced transcription inhibition and apoptotic signalling. In addition, CDDP targets the endoplasmic reticulum (ER) to induce ER stress, the mitochondria via mitochondrial DNA damage leading to ROS production, and the plasma membrane and cytoskeletal components. CP acts in a similar fashion to CDDP by inducing DNA damage, mitochondrial damage, and ER stress. Additionally, CP is also able to upregulate micro-RNA activity, enhancing intrinsic apoptosis. OXP, on the other hand, at first induces damage to all the same targets as CDDP and CP, yet it is also capable of inducing immunogenic cell death via ER stress and can decrease ribosome biogenesis through its nucleolar effects. In this comprehensive review, we provide detailed mechanisms of action for the three platinating agents, going beyond their nuclear effects to include their cytoplasmic impact within cancer cells. In addition, we cover their current clinical use and limitations, including side effects and mechanisms of resistance.

Cisplatin induces TRPA1-mediated mechanical allodynia in the oral mucosa

OBJECTIVE

Cisplatin, a platinum-based anticancer drug, produces reactive oxygen species (ROS) in many cell types and induces mechanical allodynia in the hands and/or feet (chemotherapy-induced painful neuropathy: CIPN). In this study, we examined the possibility of inducing neuropathy in the oral region using oral keratinocytes and rats.

METHODS

Human oral keratinocytes (HOKs) were used to evaluate ROS generation after cisplatin application by a ROS-reactive fluorescent assay. In rats, after cisplatin administrations (two times), the trigeminal ganglion (TG) was investigated by electron microscopy and quantitative RT-PCR. Using our proprietary assay system, oral pain-related behaviors were observed in cisplatin-treated rats.

RESULTS

In rats, cisplatin administration reduced food intake and body weight. In electron microscopic analysis, glycogen granules in the TG were depleted following administration, although organelles were intact. In HOK cells, cisplatin significantly increased ROS generation with cell death, similar to glycolysis inhibitors. Cisplatin administration did not show any effects on Trpa1 mRNA levels in the TG. However, the same procedure induced hypersensitivity to mechanical stimulation and the TRPA1 agonist allyl isothiocyanate in the oral mucosa. Mechanical hypersensitivity was inhibited by the antioxidative drug α-lipoic acid and the TRPA1 antagonist HC-030031, similar to that of the hind paw.

CONCLUSION

The present findings suggest that cisplatin induces TRPA1-mediated CIPN due to ROS generation in the oral region. This study will provide a better understanding of persistent oral pain in cancer patients.

Capsaicin 8% patch Qutenza and other current treatments for neuropathic pain in chemotherapy-induced peripheral neuropathy (CIPN)

PURPOSE OF REVIEW

Current oral treatments for neuropathic pain associated with chemotherapy-induced peripheral neuropathy (CIPN) have limited clinical efficacy, and undesirable side-effects. Topically delivered treatments have the advantage of avoiding CNS side-effects, while relieving pain. We have reviewed treatments of neuropathic pain associated with CIPN, focusing on the Capsaicin 8% patch, which can provide pain relief for up to 3 months or longer after a single 30-60-min application.

RECENT FINDINGS

Capsaicin 8% patch is a licensed treatment in the EU/UK for neuropathic pain and shown to be safe and effective in providing pain relief for patients with CIPN. Repeated daily oral or topical administrations are not required, as with other current treatments. The side-effects are transient and restricted to the time around patch application. New evidence suggests the Capsaicin 8% patch can promote the regeneration and restoration of skin nerve fibres in CIPN, in addition to the pain relief.

SUMMARY

The Capsaicin 8% patch is now often a preferred a treatment option for localised neuropathic pain conditions, including the feet and hands in patients with CIPN. Capsaicin 8% patch can be repeated three-monthly, if needed, for a year. In addition to pain relief, it may have a disease-modifying effect.

Chemotherapy-Induced Peripheral Neuropathy and its Impact on Health-Related Quality of Life among Multiple Myeloma Patients: A Single-Center Experience

Aim

Chemotherapy-induced peripheral neuropathy (CIPN) is a long-term neurological health issue in patients diagnosed with multiple myeloma (MM). The aim of this study was to assess CIPN symptoms and health-related quality of life (HRQOL) among MM patients.

Methods

A cross-sectional survey was conducted among patients diagnosed with MM in a tertiary care hospital using a self-reported Arabic questionnaire, European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire for CIPN scale (QLQ-CIPN20). The HRQOL was assessed using EORTC multiple myeloma module (QLQ-MY20). Categorical variables were reported in frequency tables and percentages. Age and duration of MM diagnosis were reported as mean and standard deviation. Survey responses were presented using descriptive statistics.

Results

In total, 62 patients had participated. Males were 60%. The average age was 58.74 ± 11.49 years. On sensory scale, 20% reported "quite a bit"/"very much" tingling in fingers/hands, 23% in toes/feet, 39% numbness in fingers/hands, 37% in toes/feet, and 43% reported trouble standing or walking. On motor scale, 40% reported trouble walking and 60% had difficulty in climbing stairs/standing up from chair. On autonomic scale, 27% reported orthostatic hypotension and only 13/37 (46%) males reported erectile dysfunction. For HRQOL, 50% reported bone aches/pain, 42% reported back pain, 57% reported feeling ill, 33% reported lost hair, 35% had been thinking about their illness, whereas 28% were worried about future health and 22% had reported being worried about dying.

Conclusion

MM patients encounter CIPN symptoms with impaired HRQOL. Capturing CIPN as a patient-reported outcome needs to be considered in routine clinical practice.

Feasibility and efficacy of chemoradiotherapy with concurrent split-dose cisplatin after induction chemotherapy with docetaxel/cisplatin/5-fluorouracil for locally advanced head and neck cancer

Chemoradiotherapy (CRT) with concurrent high-dose cisplatin (CDDP) is a standard treatment for locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). Docetaxel plus CDDP and 5-fluorouracil (TPF) induction chemotherapy (ICT) prior to CRT is considered for patients at high risk of distant metastases. The purpose of the current study was to evaluate the feasibility and efficacy of CRT with split-dose CDDP after TPF-ICT for LA-SCCHN. A total of 21 LA-SCCHN patients treated with TPF-ICT followed by concurrent CRT with split-dose CDDP between January 2011 and December 2017 were retrospectively analysed. The patients' characteristics were i) median age 66 years (48-75 years); ii) male/female, 21/0; iii) performance status 0-1/2, 20/1; iv) larynx/hypopharynx/oropharynx/oral cavity, 4/8/8/1 and v) clinical stage III/IV, 3/18. The numbers of TPF-ICT cycles 1/2/3 were 2/3/16. Median cumulative doses of CDDP in TPF-ICT and CRT were 180.0 and 206.7 mg/m², respectively. All patients completed 70 Gy RT. The complete response rate was 76.2%. At a median follow-up of 51.5 months, median PFS and OS were not reached and 65.5 months, respectively. The most common grade 3 or worse toxicities during CRT-ICT were stomatitis (48%), dysphagia (21%), anorexia (17%) and leukopenia (14%). However, no grade 2 or worse nephrotoxicity, neurotoxicity or ototoxicity was observed. The results demonstrated that concurrent CRT with split-dose CDDP after TPF-ICT is feasible and effective for LA-SCCHN.

Cisplatin-associated neuropathy characteristics compared with those associated with other neurotoxic chemotherapy agents (Alliance A151724)

PURPOSE

The current project was developed to obtain natural history information regarding cisplatin-induced peripheral neuropathy in males with testicular/germ cell cancers and to compare such neuropathy data with similarly obtained data in patients receiving other chemotherapy drugs in similarly conducted clinical trials.

METHODS

Patients without baseline neuropathy symptoms, who were initiating cisplatin-based chemotherapy, completed the EORTC CIPN 20 patient-reported instrument to evaluate chemotherapy-induced peripheral neuropathy (CIPN). Results were compared with EORTC CIPN 20 data obtained from independent study sets regarding patients receiving (1) paclitaxel, (2) combined paclitaxel and carboplatin, (3) oxaliplatin, or (4) a combination of doxorubicin and cyclophosphamide (AC). The last study set of patients on AC was selected to evaluate the use of EORTC CIPN 20 data in patients receiving chemotherapy not known to cause CIPN.

RESULTS

Cisplatin-induced neuropathy was more similar to neuropathy in patients receiving oxaliplatin than in those receiving paclitaxel. The cisplatin and oxaliplatin groups exhibited the coasting phenomenon and more prominent upper extremity symptoms than lower extremity symptoms during chemotherapy administration weeks. In contrast, paclitaxel-treated patients did not, on average, exhibit the coasting phenomenon; additionally, lower extremity symptoms were more prominent during the weeks when paclitaxel was administered. Cisplatin-induced neuropathy was less severe than was seen in patients in the other two groups, potentially because the cisplatin-receiving patients were younger. Patients receiving AC did not report substantial EORTC CIPN 20 changes.

CONCLUSION

Understanding neuropathy similarities and differences with various chemotherapy agents may help elucidate CIPN processes and facilitate means to prevent and/or treat established CIPN.

TRIAL REGISTRATION

NCT02677727.

Chemotherapy-Induced Peripheral Neuropathy in Long-term Survivors of Childhood Cancer: Clinical, Neurophysiological, Functional, and Patient-Reported Outcomes

Importance

In light of the excellent long-term survival of childhood cancer patients, it is imperative to screen for factors affecting health, function, and quality of life in long-term survivors.

Objective

To comprehensively assess chemotherapy-induced peripheral neuropathy in childhood cancer survivors to define disease burden and functional effect and to inform screening recommendations.

Design, Setting, and Participants

In this cross-sectional observational study, cancer survivors who were treated with chemotherapy for extracranial malignancy before age 17 years were recruited consecutively between April 2015 and December 2016 from a single tertiary hospital-based comprehensive cancer survivorship clinic and compared with healthy age-matched controls. Investigators were blinded to the type of chemotherapy. A total of 169 patients met inclusion criteria, of whom 48 (28.4%) were unable to be contacted or declined participation.

Exposures

Chemotherapy agents known to be toxic to peripheral nerves.

Main Outcomes and Measures

The clinical peripheral neurological assessment using the Total Neuropathy Score was compared between recipients of different neurotoxic chemotherapy agents and control participants and was correlated with neurophysiological, functional, and patient-reported outcome measures.

Results

Of the 121 childhood cancer survivors included in this study, 65 (53.7%) were male, and the cohort underwent neurotoxicity assessments at a median (range) age of 16 (7-47) years, a median (range) 8.5 (1.5-29) years after treatment completion. Vinca alkaloids and platinum compounds were the main neurotoxic agents. Clinical abnormalities consistent with peripheral neuropathy were common, seen in 53 of 100 participants (53.0%) treated with neurotoxic chemotherapy (mean Total Neuropathy Score increase, 2.1; 95% CI, 1.4-2.9; P < .001), and were associated with lower limb predominant sensory axonal neuropathy (mean amplitude reduction, 5.8 μV; 95% CI, 2.8-8.8; P < .001). Functional deficits were seen in manual dexterity, distal sensation, and balance. Patient-reported outcomes demonstrating reduction in global quality of life and physical functioning were associated with the Total Neuropathy Score. Cisplatin produced long-term neurotoxicity more frequently than vinca alkaloids.

Conclusions and Relevance

Clinical abnormalities attributable to peripheral neuropathy were common in childhood cancer survivors and persisted long term, with concurrent deficits in patient-reported outcomes. Both the type of neurotoxic agent and a targeted clinical neurological assessment are important considerations when screening survivors for long-term neuropathy. Further development of peripheral neuropathy-specific pediatric assessment tools will aid research into neuroprotective and rehabilitative strategies.

Chemotherapy-Related Encephalopathy With Super-Refractory Status Epilepticus in a Child With Osteosarcoma: A Case Report With a Review of Literature

Osteosarcoma is the most frequent primary cancer of the bones, and a combination of primary chemotherapy, surgery, and adjuvant chemotherapy is its current treatment. In adults, some authors have reported problems with memory and concentration following chemotherapy, but in children, severe neurologic dysfunction has been rarely reported. This report describes a 13-year-old patient with primary high-grade nonmetastatic osteosarcoma of the tibia who developed encephalopathy with super-refractory status epilepticus related to chemotherapy. He received methotrexate (MTX) and cisplatin (CDDP)-containing polychemotherapy, and after the first course of drug administration, he developed fever, confusion, a state of psychomotor agitation, and super-refractory status epilepticus with normal laboratory and imaging findings. The causal relationship between the administration of the first polychemotherapy course and his neurological manifestations may be supported by the evaluation and exclusion of other causes. The administration of antiepileptic drugs and off-label atypical antipsychotics was necessary to treat his neurological complications and behavioral changes. This patient represents the first known example of super-refractory status epilepticus in a child treated with MTX and CDDP-containing chemotherapy. Physicians should be aware that encephalopathy and seizures are possible consequences of CDDP therapy when administered alone or in combination with other chemotherapeutic agents. Further studies are needed to better define this relationship in children.

Inflammatory and Neuropathic Gene Expression Signatures of Chemotherapy-Induced Neuropathy Induced by Vincristine, Cisplatin, and Oxaliplatin in C57BL/6J Mice

Vincristine, oxaliplatin, and cisplatin are commonly prescribed chemotherapeutic agents for the treatment of many tumors. However, a main side effect is chemotherapy-induced peripheral neuropathy (CIPN), which may lead to changes in chemotherapeutic treatment. Although symptoms associated with CIPN are recapitulated by mouse models, there is limited knowledge of how these drugs affect the expression of genes in sensory neurons. The present study carried out a transcriptomic analysis of dorsal root ganglia following vincristine, oxaliplatin, and cisplatin treatment with a view to gain insight into the comparative pathophysiological mechanisms of CIPN. RNA-Seq revealed 368, 295, and 256 differential expressed genes induced by treatment with vincristine, oxaliplatin, and cisplatin, respectively, and only 5 shared genes were dysregulated in all 3 groups. Cell type enrichment analysis and gene set enrichment analysis showed predominant effects on genes associated with the immune system after treatment with vincristine, while oxaliplatin treatment affected mainly neuronal genes. Treatment with cisplatin resulted in a mixed gene expression signature. PERSPECTIVE: These results provide insight into the recruitment of immune responses to dorsal root ganglia and indicate enhanced neuroinflammatory processes following administration of vincristine, oxaliplatin, and cisplatin. These gene expression signatures may provide insight into novel drug targets for treatment of CIPN.

The Influence of Chemotherapy-Induced Peripheral Neuropathy on Quality of Life of Gynecologic Cancer Survivors

OBJECTIVE

The aim of this observational study was to investigate correlations between long-term chemotherapy-induced peripheral neurotoxicity (CIPN) and quality of life (physical well-being, social well-being, emotional well-being, and functional well-being [FWB]) among survivors of gynecologic cancer (GC).

METHODS

We aimed to assess the correlation of quality of life and long-term CIPN with the temporal change in recurrence-free GC survival. Questionnaire responses and clinical data of 259 GC survivors were collected and assessed according to treatment received. The χ test was used to determine the significance of correlations.

RESULTS

Of 165 evaluable patients treated by chemotherapy, 36 patients (21.8%) developed CIPN of Common Toxicity Criteria for Adverse Events grade 1 or higher during the study. Chemotherapy-induced peripheral neurotoxicity had significantly improved over time in the domain of FWB at 61 months or more after the end of chemotherapy (posttreatment 4) among GC survivors (P = 0.003). Furthermore, CIPN treated by more than 6 courses of the paclitaxel and carboplatin regimen among GC survivors showed significant improvement over time in the emotional well-being domain at 25 to 60 months and 61 months or more after the end of chemotherapy (posttreatments 3 and 4) (P = 0.037 and P = 0.023) and in FWB at posttreatment 4 (P < 0.001).

CONCLUSIONS

Emotional and functional domains of CIPN improved over time among GC survivors treated by more than 6 courses of the paclitaxel and carboplatin regimen. Based on these results, further research is required to identify additional preventative or curative approaches.

A Prospective Study of Chronic Oxaliplatin-Induced Neuropathy in Patients with Colon Cancer: Long-Term Outcomes and Predictors of Severe Oxaliplatin-Induced Neuropathy

Background and Purpose

The objective of this study was to determine the incidence and long-term outcomes of oxaliplatin-induced peripheral neuropathy (OIPN), as well as predictors of its severe form.

Methods

Sixty-nine patients who were taking oxaliplatin for colon cancer were prospectively followed prior to starting chemotherapy and after 4, 8, and 12 cycles of chemotherapy. Thirty-six patients completed the follow-up at 1 year after the end of chemotherapy. The patients were assessed using clinical assessment scales and nerve conduction studies (NCS) at each follow-up visit.

Results

By applying the National Cancer Institute Common Toxicity criteria, OIPN was classified as grade 1 in 30 (44%) patients, grade 2 in 25 (36%), and grade 3 in 10 (14%) at the completion of therapy. At 1 year after the treatment, OIPN of grades 1, 2, and 3 was found in 50, 3, and 11% of the patients, respectively. Multivariate analysis showed that reductions of the amplitude of the sensory action potential of >11.5% in the median nerve between baseline and four cycles of chemotherapy (odds ratio=5.603, p=0.031) and of >22.5% in the sural nerve between four and eight cycles of chemotherapy (odds ratio=5.603, p=0.031) were independently associated with the risk of developing grade-3 OIPN.

Conclusions

While the severity of OIPN can improve after oxaliplatin discontinuation, more than half of the patients in this study still had OIPN at 1 year after discontinuation. Early changes in the NCS results for sensory nerves can predict the development of severe OIPN during treatment.

[Clinical and electromyography characteristics of chemotherapy-induced polyneuropathy]

AIM

The study aimed at determining clinical and electromyography characteristics and developing the methods of CIPN treatment.

MATERIAL AND METHODS

A clinical and electromyographic examinations and treatment of 30 with CIPN symptoms developed after polychemotherapy were performed. The authors developed treatment schemes included allopathic, homeopathic drugs, hydrotherapy and pharmacopuncture.

RESULTS AND CONCLUSION

Most of the patients were diagnosed with axonal polyneuropathy with affection of long nerves of the limbs, some patients had a combination of axonopathy with myelopathy. After treatment, regression of neuropathy symptoms and improvement of quality of life was noted in all patients.

Pathophysiology of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced neuropathy is a common, dose-dependent adverse effect of several antineoplastics. It can lead to detrimental dose reductions and discontinuation of treatment, and severely affects the quality of life of cancer survivors. Clinically, chemotherapy-induced peripheral neuropathy presents as deficits in sensory, motor, and autonomic function which develop in a glove and stocking distribution due to preferential effects on longer axons. The pathophysiological processes are multi-factorial and involve oxidative stress, apoptotic mechanisms, altered calcium homeostasis, axon degeneration and membrane remodeling as well as immune processes and neuroinflammation. This review focusses on the commonly used antineoplastic substances oxaliplatin, cisplatin, vincristine, docetaxel, and paclitaxel which interfere with the cancer cell cycle-leading to cell death and tumor degradation-and cause severe acute and chronic peripheral neuropathies. We discuss drug mechanism of action and pharmacokinetic disposition relevant to the development of peripheral neuropathy, the epidemiology and clinical presentation of chemotherapy-induced neuropathy, emerging insight into genetic susceptibilities as well as current understanding of the pathophysiology and treatment approaches.

Neurophysiological and clinical outcomes in chemotherapy-induced neuropathy in cancer

Chemotherapy induced peripheral neuropathy (CIPN) is a significant toxicity of cancer treatment, with the potential to affect long-term function and quality of life in cancer survivors. There remains a lack of consensus around optimal assessment techniques. While current approaches to CIPN assessment are focused on clinical grading scales, it is becoming increasingly evident that a more comprehensive multimodal assessment package is necessary to accurately characterise the impact of CIPN as well as gauge the utility of neuroprotective mechanisms. Neurophysiological techniques provide objective biomarkers and may enable early detection of toxicity while patient reported outcomes are necessary to determine the significance of symptoms to individual patients. In addition to providing an objective assessment, clinical neurophysiological techniques provide important insights into the contributory pathophysiological mechanisms of CIPN with different chemotherapy agents. There is a paucity of implementation of these techniques in the clinical trial setting. The present Review aims to facilitate the use of neurophysiological studies as part of comprehensive assessment packages for the monitoring of CIPN by summarising current understanding of neurophysiological changes that underlie the development of neuropathy, clinical presentations and patient reported outcomes as well as advantages and limitations of current techniques for the neurophysiological assessment of CIPN.

Reference data of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-CIPN20 Questionnaire in the general Dutch population

OBJECTIVE

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side-effect of chemotherapy. However, CIPN symptoms are also reported by patients not receiving chemotherapy. Normative data could help interpret CIPN among cancer patients. Our aim was to generate normative data for the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-CIPN20 Questionnaire designed to assess CIPN from the patients' perspective. The normative CIPN data have also been generated for stratified subgroups formed on the basis of sex, age and comorbidity.

METHODS

The QLQ-CIPN20 and the Self-administered Comorbidity Questionnaire were administered to a representative panel of the Dutch-speaking population in the Netherlands.

RESULTS

Two thousand one hundred and two (78%) of those invited completed the questionnaires. The majority reported no CIPN symptoms (83-97%). Cronbach's alpha coefficients for the sum score, and sensory, motor and autonomic subscales were 0.87, 0.76, 0.82 and 0.49, respectively. Compared with men, women scored significantly worse on the sum score (men, 3.0 versus women, 4.3; p < 0.001), motor scale (2.7 versus 5.1; p < 0.001) and autonomic scale (3.8 versus 5.2; p < 0.01), but this difference was not clinically relevant. CIPN symptoms increased significantly with age among both men (for the sum score and all scales) and women (for the sum score, sensory and motor scale). Those with self-reported comorbidities reported significantly more CIPN symptoms, both statistically and clinically, than those without. For instance, they had a lower mean sum score (1.5) compared to those with asthma/chronic obstructive pulmonary disease (COPD; 6.9), diabetes (5.9), heart disease (8.0), hypertension (6.2), osteoarthritis (9.6) and rheumatoid arthritis (13.8).

CONCLUSIONS

A low prevalence of neuropathy was observed in the normative population without cancer, although neuropathy did increase with age and the presence of comorbidities. These data (which is freely available) can aid in the interpretation of QLQ-CIPN20 scores and can help increase our understanding of the influence of age, sex and comorbid conditions on CIPN among cancer patients.

Efficacy of Japanese traditional (Kampo) medicine for treating chemotherapy-induced peripheral neuropathy: A retrospective case series study

AIM

To investigate Japanese traditional (Kampo) medicine’s effectiveness on cancer chemotherapy-induced peripheral neuropathy (CIPN), we carried out this retrospective study.

METHODS

By searching our outpatient database of 3154 patients who consulted our outpatient clinic of Japanese-Oriental (Kampo) Medicine at Chiba University Hospital from November 2005 to December 2010, a total of 281 patients diagnosed with cancer were identified. Twenty-four patients out of the 281 patients identified met the following three conditions and were eligible for further investigation of the effectiveness of Kampo treatment: At least one course of cancer chemotherapy had been administered; numbness and pain appeared after the chemotherapy; and CIPN was diagnosed before they were given Kampo treatment.

RESULTS

The 24 patients included 6 males and 18 females and ranged in age from 39 to 86 (mean 61.2 ± 11.5) years old. Kampo formulas were individually chosen by Kampo expert doctors based on Kampo-specific diagnostics. Beneficial outcomes were obtained by Kampo treatment in 20 out of the 24 cases (83.3%). Nine out 20 cases had a major response (the numbness and pain showed improvement or reduction by 50% or more), with 7 of 9 cases showing a more than 70% symptom reduction. Eleven out of 20 cases showed a minor response (less than 50% symptom reduction), and 4 out of the 24 cases had no beneficial response. The most frequently used formula was goshajinkigan (GJG), followed by hachimijiogan (HJG) and keishibukuryogan. Thirteen of the 24 cases (54.2%) were prescribed aconite root-containing formulas including GJG and HJG. Aconite root has “warming” effects and ameliorates pain and numbness; 21 out of 24 cases (87.5%) in total used warming formulas such as aconite root-containing formulas to reduce CIPN.

CONCLUSION

Our current study suggested that Kampo formulas chosen based on Kampo-specific diagnostics could be for treating CIPN that is refractory to conventional medicine.

Influence of dosing times on cisplatin-induced peripheral neuropathy in rats

BACKGROUND

Although cis-diamminedichloro-platinum (CDDP) exhibits strong therapeutic effects in cancer chemotherapy, its adverse effects such as peripheral neuropathy, nephropathy, and vomiting are dose-limiting factors. Previous studies reported that chronotherapy decreased CDDP-induced nephropathy and vomiting. In the present study, we investigated the influence of dosing times on CDDP-induced peripheral neuropathy in rats.

METHODS

CDDP (4 mg/kg) was administered intravenously at 5:00 or 17:00 every 7 days for 4 weeks to male Sprague-Dawley rats, and saline was given to the control group. To assess the dosing time dependency of peripheral neuropathy, von-Frey test and hot-plate test were performed.

RESULTS

In order to estimate hypoalgesia, the hot-plate test was performed in rats administered CDDP weekly for 4 weeks. On day 28, the withdrawal latency to thermal stimulation was significantly prolonged in the 17:00-treated group than in the control and 5:00-treated groups. When the von-Frey test was performed to assess mechanical allodynia, the withdrawal threshold was significantly lower in the 5:00 and 17:00-treated groups than in the control group on day 6 after the first CDDP dose. The 5:00-treated group maintained allodynia throughout the experiment with the repeated administration of CDDP, whereas the 17:00-treated group deteriorated from allodynia to hypoalgesia.

CONCLUSIONS

It was revealed that the severe of CDDP-induced peripheral neuropathy was inhibited in the 5:00-treated group, whereas CDDP-treated groups exhibited mechanical allodynia. These results suggested that the selection of an optimal dosing time ameliorated CDDP-induced peripheral neuropathy.

Neurologic Complications of Commonly Used Drugs in the Hospital Setting

This chapter reviews the neurologic complications of medications administered in the hospital setting, by class, introducing both common and less common side effects. Detail is devoted to the interaction between pain, analgesia, sedation, and their residual consequences. Antimicrobials are given in nearly every hospital setting, and we review their capacity to produce neurologic sequelae with special devotion to cefepime and the antiviral treatment of human immunodeficiency virus. The management of hemorrhagic stroke has become more complex with the introduction of novel oral anticoagulants, and we provide an update on what is known about reversal of the new oral anticoagulants. Both central and peripheral nervous system complications of immunosuppressants and chemotherapies are reviewed. Because diagnosis is generally based on clinical acumen, alone, neurotoxic syndromes resulting from psychotropic medications may be easily overlooked until severe dysautonomia develops. We include a practical approach to the diagnosis of serotonin syndrome and neuroleptic malignant syndrome.

Clinical Course of Oxaliplatin-Induced Neuropathy: Results From the Randomized Phase III Trial N08CB (Alliance)

PURPOSE

Given that the clinical course of oxaliplatin-induced neuropathy is not well defined, the current study was performed to better understand clinical parameters associated with its presentation.

METHODS

Acute and chronic neuropathy was evaluated in patients receiving adjuvant FOLFOX (fluorouracil, leucovorin, and oxaliplatin) on study N08CB (North Central Cancer Treatment Group, Alliance). Acute neuropathy was assessed by having patients complete daily questionnaires for 6 days with each cycle of FOLFOX. Before each dose of FOLFOX and as long as 18 months after chemotherapy cessation, chronic neurotoxicity was assessed with use of the 20-item, European Organisation for Research and Treatment of Cancer quality-of-life questionnaire for patients with chemotherapy-induced peripheral neuropathy.

RESULTS

Three hundred eight (89%) of the 346 patients had at least one symptom of acute neuropathy with the first cycle of FOLFOX; these symptoms included sensitivity to touching cold items (71%), sensitivity to swallowing cold items (71%), throat discomfort (63%), or muscle cramps (42%). Acute symptoms peaked at day 3 and improved, although they did not always resolve completely between treatments. These symptoms were about twice as severe in cycles 2 through 12 as they were in cycle 1. For chronic neurotoxicity, tingling was the most severe symptom, followed by numbness and then pain. During chemotherapy, symptoms in the hands were more prominent than they were in the feet; by 18 months, symptoms were more severe in the feet than they were in the hands. Patients with more severe acute neuropathy during the first cycle of therapy experienced more chronic sensory neurotoxicity (P < .0001).

CONCLUSION

Acute oxaliplatin-induced neuropathy symptoms do not always completely resolve between treatment cycles and are only half as severe on the first cycle as compared with subsequent cycles. There is a correlation between the severities of acute and chronic neuropathies.

Optimization and pharmacological characterization of a refined cisplatin-induced rat model of peripheral neuropathic pain

Chemotherapy-induced peripheral neuropathy (CIPN) is the major dose-limiting side-effect of many front-line anticancer drugs. This study was designed to establish and pharmacologically characterize a refined rat model of cisplatin-induced CIPN. Adult male Sprague-Dawley rats received four (n=18) or five (n=18) single intraperitoneal bolus doses of cisplatin at 3 mg/kg, or saline (control group), once-weekly. Body weight and general health were assessed over a 49-day study period. von Frey filaments and the Hargreaves test were used to define the time course for the development of mechanical allodynia and thermal hypoalgesia in the hindpaws and for efficacy assessment of analgesic/adjuvant agents. The general health of rats administered four cisplatin doses was superior to that of rats administered five doses. Mechanical allodynia was fully developed (paw withdrawal thresholds≤6 g) in the bilateral hindpaws from day 32 to 49 for both cisplatin dosing regimens. They also showed significant thermal hypoalgesia in the bilateral hindpaws. In cisplatin-treated rats with paw withdrawal thresholds of up to 6 g, single bolus doses of gabapentin and morphine produced dose-dependent analgesia, whereas meloxicam and amitriptyline lacked efficacy. We have established and pharmacologically characterized a refined rat model of CIPN that is suitable for efficacy profiling of compounds from analgesic discovery programmes.

Chemotherapy-induced peripheral neuropathy, physical activity and health-related quality of life among colorectal cancer survivors from the PROFILES registry

PURPOSE

To gain insight into the association of physical activity (PA), chemotherapy-induced peripheral neuropathy (CIPN) and health-related quality of life among colorectal cancer survivors, up to 11 years after diagnosis.

METHODS

Data of the second data wave of a Dutch prospective population-based survey among colorectal cancer survivors diagnosed between 2000 and 2009 as registered by the Eindhoven Cancer Registry was used. Eighty-three percent (n = 1648) of patients filled out the EORTC QLQ-C30 and the EORTC QLQ-CIPN20 of which 506 patients (31%) were treated with chemotherapy.

RESULTS

Treatment with chemotherapy was associated with a higher percentage of patients reporting CIPN symptoms regardless of PA. Furthermore, not meeting the Dutch PA guideline of 150 min of moderate to vigorous PA a week was associated with more CIPN among patients treated with chemotherapy. Also patients not treated with chemotherapy reported CIPN-like symptoms, especially when not meeting the PA guideline. Statistically significant and clinically relevant worse scores on almost all EORTC QLQ-C30 subscales were reported by those not meeting the PA guideline compared to those who did meet the guideline, regardless of CIPN symptoms. However, these differences were more pronounced in the group with many CIPN symptoms (e.g. upper 30%).

IMPLICATIONS FOR CANCER SURVIVORS

Alertness among health care professionals and patients for the importance of PA is warranted, as meeting the PA guideline was associated with less CIPN-like symptoms and a higher health-related quality of life regardless of treatment with chemotherapy.

Chemotherapy-induced peripheral neuropathy: What do we know about mechanisms?

Cisplatin, oxaliplatin, paclitaxel, vincristine and bortezomib are some of the most effective drugs successfully employed (alone or in combinations) as first-line treatment for common cancers. However they often caused severe peripheral neurotoxicity and neuropathic pain. Structural deficits in Dorsal Root Ganglia and sensory nerves caused symptoms as sensory loss, paresthesia, dysaesthesia and numbness that result in patient' suffering and also limit the life-saving therapy. Several scientists have explored the various mechanisms involved in the onset of chemotherapy-related peripheral neurotoxicity identifying molecular targets useful for the development of selected neuroprotective strategies. Dorsal Root Ganglia sensory neurons, satellite cells, Schwann cells, as well as neuronal and glial cells in the spinal cord, are the preferential sites in which chemotherapy neurotoxicity occurs. DNA damage, alterations in cellular system repairs, mitochondria changes, increased intracellular reactive oxygen species, alterations in ion channels, glutamate signalling, MAP-kinases and nociceptors ectopic activation are among the events that trigger the onset of peripheral neurotoxicity and neuropathic pain. In the present work we review the role of the main players in determining the pathogenesis of anticancer drugs-induced peripheral neuropathy.

Neuropathic pain in cancer survivors

The occurrence of pain in cancer survivors may be debilitating. These pain syndromes may be of different types, including neuropathic pain. The research related to cancer management has been done extensively in certain areas, but such research in cancer survivors is still lacking. The chronic pain in cancer survivors is not only under-reported but also under-treated. The assessment of pain in cancer survivors is multifaceted because of many domains like physical, social and psychological. Usually, the pain management may be considered similar to that for chronic noncancer pain, but with a caveat that such pain may at times be indicative of cancer recurrence. The multidisciplinary and multimodal management is essential for such neuralgic pain in cancer survivors. This may require a balanced combination of pharmacological and nonpharmacological techniques, including psychological support. The overall goal that remains in such patients for pain management is to improve the quality of life. Here we review certain pertinent aspects of neuropathic pain in cancer survivors.

Pathobiology of cancer chemotherapy-induced peripheral neuropathy (CIPN)

Chemotherapy induced peripheral neuropathy (CIPN) is a type of neuropathic pain that is a major dose-limiting side-effect of potentially curative cancer chemotherapy treatment regimens that develops in a "stocking and glove" distribution. When pain is severe, a change to less effective chemotherapy agents may be required, or patients may choose to discontinue treatment. Medications used to alleviate CIPN often lack efficacy and/or have unacceptable side-effects. Hence the unmet medical need for novel analgesics for relief of this painful condition has driven establishment of rodent models of CIPN. New insights on the pathobiology of CIPN gained using these models are discussed in this review. These include mitochondrial dysfunction and oxidative stress that are implicated as key mechanisms in the development of CIPN. Associated structural changes in peripheral nerves include neuronopathy, axonopathy and/or myelinopathy, especially intra-epidermal nerve fiber (IENF) degeneration. In patients with CIPN, loss of heat sensitivity is a hallmark symptom due to preferential damage to myelinated primary afferent sensory nerve fibers in the presence or absence of demyelination. The pathobiology of CIPN is complex as cancer chemotherapy treatment regimens frequently involve drug combinations. Adding to this complexity, there are also subtle differences in the pathobiological consequences of commonly used cancer chemotherapy drugs, viz platinum compounds, taxanes, vincristine, bortezomib, thalidomide and ixabepilone, on peripheral nerves.

Clinical course and risk factors of neurotoxicity following cisplatin in an intensive dosing schedule

An intensive weekly regimen of cisplatin was administered to 66 patients with solid cancer in doses varying from 70 to 85 mg/m(2) . The occurrence of sensory neuropathy was prospectively examined by assessment of neuropathic signs and symptoms and measurement of vibration perception threshold (VPT). Evaluation was performed before initiation of therapy and during follow-up until 3-12 months after the last cycle of cisplatin. A mild or moderate neuropathy developed in 47% of patients at 2 weeks after treatment This neuropathy continued to deteriorate until approximately 3 months after cessation of chemotherapy leading to a mild or moderate neuropathy in 71% of patients and a severe neuropathy in 9% of patients. Thereafter we observed a gradual but incomplete recovery. The high incidence of neuropathy we found may be explained by the prolonged observation period compared with earlier reports. The only factor correlated with severity of neuropathy was the cumulative dose of cisplatin, while there was no association with either pre-treatment VPT, age, sex, tumor type or co-treatment with etoposide. The progressing course up to approximately 3 months after the end of treatment underscores the need for prolonged follow-up in future studies on cisplatin neuropathy.-

Chemotherapy-induced peripheral neurotoxicity: a critical analysis

With a 3-fold increase in the number of cancer survivors noted since the 1970s, there are now over 28 million cancer survivors worldwide. Accordingly, there is a heightened awareness of long-term toxicities and the impact on quality of life following treatment in cancer survivors. This review will address the increasing importance and challenge of chemotherapy-induced neurotoxicity, with a focus on neuropathy associated with the treatment of breast cancer, colorectal cancer, testicular cancer, and hematological cancers. An overview of the diagnosis, symptomatology, and pathophysiology of chemotherapy-induced peripheral neuropathy will be provided, with a critical analysis of assessment strategies, neuroprotective approaches, and potential treatments. The review will concentrate on neuropathy associated with taxanes, platinum compounds, vinca alkaloids, thalidomide, and bortezomib, providing clinical information specific to these chemotherapies.

Efficacy of contact needle therapy for chemotherapy-induced peripheral neuropathy

Cancer chemotherapy-induced peripheral neuropathy (CIPN) often results in discontinuation of treatment with potentially useful anticancer drugs and may deteriorate the patient's quality of life. This study investigated the effect of contact needle therapy (CNT) on CIPN caused by responsible chemotherapeutic agents as taxanes and oxaliplatin. Six patients with CIPN were treated with CNT. The severity of CIPN was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version 4 and FACT/GOG-Ntx before and after CNT. After the treatment, all of the patients showed some improvement. Four patients showed apparent improvement in breakthrough pain. One of the cases had difficulty in walking because of CIPN in lower extremities, but after 2 times of CNT, he could walk without pain and could continue the chemotherapy. Although its putative mechanisms remain elusive, CNT has strong potential as an adjunctive therapy in CIPN. Well-designed clinical trials with adequate sample size and power are necessary to confirm the findings of this study.

Drug-induced neuropathies

Although drug-induced neuropathies account for only 2-4% of referrals, their identification is important. Numerically, chemotherapy and antiretroviral drugs are the most important worldwide. Research is currently focused on elucidating pathogenic mechanisms and the earliest presymptomatic changes using neurophysiological and pharmacogenetic techniques in order to avoid the drug or make dosage changes before irreversible damage occurs. Chemoprotectants against chemotherapy-induced neuropathy are also an active area of research. This chapter focuses on the pathophysiology of drug-induced neuropathies in general, followed by detailed reviews of neuropathy due to; newer compounds such as TNF (tumor necrosis factor) α antagonists and antibiotics such as linezolid; chemotherapeutic agents, old and new, where significant progress has been made; antiretroviral drugs; and amiodarone, which is unusual in that it causes a demyelinating neuropathy. The controversial issue of statin-induced neuropathy is also reviewed.

Acute cold hypersensitivity characteristically induced by oxaliplatin is caused by the enhanced responsiveness of TRPA1 in mice

Background

Oxaliplatin, a platinum-based chemotherapeutic agent, causes an unusual acute peripheral neuropathy. Oxaliplatin-induced acute peripheral neuropathy appears in almost all patients rapidly after infusion, and is triggered or exacerbated by cold, while its mechanisms are poorly understood. In this study, the involvement of thermosensitive transient receptor potential channels (TRPA1, TRPM8 and TRPV1) in oxaliplatin-induced acute hypersensitivity was investigated in mice.

Results

A single intraperitoneal administration of oxaliplatin (1–10 mg/kg) induced cold but not mechanical hypersensitivity within 2 h in a dose-dependent manner. Infusion of the oxaliplatin metabolite, oxalate (1.7 mg/kg), also induced acute cold hypersensitivity, while another platinum-based chemotherapeutic agent, cisplatin (5 mg/kg), or the non-platinum-containing chemotherapeutic agent, paclitaxel (6 mg/kg) failed to induce mechanical or cold hypersensitivity. The oxaliplatin-induced acute cold hypersensitivity was abolished by the TRPA1 antagonist HC-030031 (100 mg/kg) and by TRPA1 deficiency. The nocifensive behaviors evoked by intraplantar injections of allyl-isothiocyanate (AITC; TRPA1 agonist) were significantly enhanced in mice treated for 2 h with oxaliplatin (1–10 mg/kg) in a dose-dependent manner, while capsaicin (TRPV1 agonist)-evoked nocifensive behaviors were not affected. Menthol (TRPM8/TRPA1 agonist)-evoked nocifensive-like behaviors were also enhanced by oxaliplatin pretreatment, which were inhibited by TRPA1 deficiency. Similarly, oxalate enhanced, but neither cisplatin nor paclitaxel affected AITC-evoked nocifensive behaviors. Pretreatment of cultured mouse dorsal root ganglia (DRG) neurons with oxaliplatin (30–300 μM) for 1, 2, or 4 h significantly increased the number of AITC-sensitive neurons in a concentration-dependent manner whereas there was no change in the number of menthol- or capsaicin-sensitive neurons.

Conclusions

Taken together, these results suggest that a brief treatment with oxaliplatin or its metabolite oxalate is sufficient to enhance the responsiveness of TRPA1 but not that of TRPM8 and TRPV1 expressed by DRG neurons, which may contribute to the characteristic acute peripheral neuropathy induced by oxaliplatin.

The relationship between numbness, tingling, and shooting/burning pain in patients with chemotherapy-induced peripheral neuropathy (CIPN) as measured by the EORTC QLQ-CIPN20 instrument, N06CA

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is characterized by numbness, tingling, and shooting/burning pain. This analysis was performed to describe the relationship between numbness, tingling, and shooting/burning pain in patients with CIPN, as reported using the EORTC QLQ-CIPN20 (CIPN20).

METHODS

Baseline CIPN20 data were provided for all patients on a prospective trial designed to treat patients with bothersome CIPN. Baseline frequencies for the items on the CIPN20 are primarily described by descriptive statistics and histograms, with correlational analyses between individual items.

RESULTS

A majority of the 199 patients accrued to this study reported "quite a bit" to "very much" numbness (57%) or tingling (63%) in the hands compared to "a little" or "not at all" (numbness (43%), tingling (38%)). Fewer patients reported "quite a bit" to "very much" shooting/burning pain in the hands (18%). Numbness and tingling in the hands were highly correlated (r = 0.69), while neither were highly correlated with shooting/burning pain. Similar results were observed in the feet. More severe ratings for tingling and shooting/burning pain were ascribed to the lower extremities, as opposed to the upper extremities.

CONCLUSIONS

In patients with CIPN, severe sensory neuropathy symptoms (numbness, tingling) commonly exist without severe neuropathic pain symptoms (shooting/burning pain), while the reverse is not common. Symptoms in the feet should be evaluated distinctly from those in the hands as the experience of symptoms is not identical, for individual patients, in upper versus lower extremities.

A double-blind, placebo-controlled trial of a topical treatment for chemotherapy-induced peripheral neuropathy: NCCTG trial N06CA

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a troublesome chronic symptom that has no proven pharmacologic treatment. The purpose of this double-blind randomized placebo-controlled trial was to evaluate a novel compounded topical gel for this problem.

METHODS

Patients with CIPN were randomized to baclofen 10 mg, amitriptyline HCL 40 mg, and ketamine 20 mg in a pluronic lecithin organogel (BAK-PLO) versus placebo (PLO) to determine its effect on numbness, tingling, pain, and function. The primary endpoint was the baseline-adjusted sensory subscale of the EORTC QLQ-CIPN20, at 4 weeks.

RESULTS

Data in 208 patients reveal a trend for improvement that is greater in the BAK-PLO arm over placebo in both the sensory (p = 0.053) and motor subscales (p = 0.021). The greatest improvements were related to the symptoms of tingling, cramping, and shooting/burning pain in the hands as well as difficulty in holding a pen. There were no undesirable toxicities associated with the BAK-PLO and no evidence of systemic toxicity.

CONCLUSION

Topical treatment with BAK-PLO appears to somewhat improve symptoms of CIPN. This topical gel was well tolerated, without evident systemic toxicity. Further research is needed with increased doses to better clarify the clinical role of this treatment in CIPN.

Premature aging-related peripheral neuropathy in a mouse model of progeria

Peripheral neuropathy is a common aging-related degenerative disorder that interferes with daily activities and leads to increased risk of falls and injury in the elderly. The etiology of most aging-related peripheral neuropathy is unknown. Inherited defects in several genome maintenance mechanisms cause tissue-specific accelerated aging, including neurodegeneration. We tested the hypothesis that a murine model of XFE progeroid syndrome, caused by reduced expression of ERCC1-XPF DNA repair endonuclease, develops peripheral neuropathy. Nerve conduction studies revealed normal nerve function in young adult (8 week) Ercc1(-/Δ) mice, but significant abnormalities in 20 week-old animals. Morphologic and ultrastructural analysis of the sciatic nerve from mutant mice revealed significant alterations at 20 but not 8 weeks of age. We conclude that Ercc1(-/Δ) mice have accelerated spontaneous peripheral neurodegeneration that mimics aging-related disease. This provides strong evidence that DNA damage can drive peripheral neuropathy and offers a rapid and novel model to test therapies.

Early, progressive, and sustained dysfunction of sensory axons underlies paclitaxel-induced neuropathy

Paclitaxel is used in the adjuvant treatment of breast cancer. It induces disabling and potentially long-lasting sensory neuropathy. This study systematically and prospectively investigated sensory function, using clinical grading scales, quantitative sensory testing, and neurophysiological and nerve excitability studies in 28 patients with early-stage breast cancer. After administration of 529 ± 41 mg/m(2) paclitaxel, 71% of patients developed neuropathic symptoms by 6 weeks of treatment. Early and progressive increases in stimulus threshold (P < 0.05) and reduction in sensory amplitudes from 47.0 ± 3.3 μV to 42.4 ± 3.4 μV (P < 0.05) occurred by 4 weeks, with a further reduction by final treatment (33.7 ± 3.0 μV, P < 0.001). The majority of patients (63%) did not experience recovery of neuropathic symptoms at follow-up. Axonal disruption did not relate to membrane conductance dysfunction. We found that paclitaxel produces early sensory dysfunction and leads to persistent neuropathy. Importantly, significant axonal dysfunction within the first month of treatment predated symptom onset, suggesting a window for neuroprotective therapies.

Persistent mobility disability after neurotoxic chemotherapy

BACKGROUND AND PURPOSE

The impact of cancer and its treatments on balance and functional mobility in older adults remains unknown but is increasingly important, given the evolution of cancer treatments. Subacute and more persistent side effects such as chemotherapy-induced peripheral neuropathy are on the rise, and the effects on mobility and balance, as well as the prognosis for resolution of any functional deficits, must be established before interventions can be trialed. The purpose of this case report is to describe the severity and long-term persistence of mobility decline in an older adult who received neurotoxic chemotherapy. To our knowledge, this is the first case report to describe an older adult with chemotherapy-induced peripheral neuropathy using results of standardized balance and mobility tests and to focus on prognosis by repeating these measures more than 2 years after chemotherapy.

CASE DESCRIPTION

An 81-year-old woman received a neurotoxic agent (paclitaxel) after curative mastectomy for breast cancer. Baseline testing prior to taxane therapy revealed a socially active woman with no reported functional deficits or neuropathic symptoms, 1.2-m/s gait speed, and performance at the ceiling on balance and gait portions of a standardized mobility measure.

OUTCOMES

After 3 cycles, paclitaxel therapy was stopped by the oncologist because of neurotoxicity. Declines as large as 50% were seen in performance-based measures at 12 weeks and persisted at 2.5 years, and the patient reported recurrent falls, cane use, and mobility-related disability.

DISCUSSION

This case highlights the extent to which function can decline in an older individual receiving neurotoxic chemotherapy, the potential for these deficits to persist years after treatment is stopped, and the need for physical therapy intervention and further research in this population.

Persistent neuropathy after treatment with cisplatin and oxaliplatin

BACKGROUND

The aims of the current explorative study were to assess persistent neuropathy in 45 patients up to 6 years after treatment with cisplatin or oxaliplatin and to determine the most adequate method to evaluate neuropathy. Furthermore, the effect of possible determinants on persistent neuropathy was investigated.

MATERIAL AND METHODS

The assessment of neuropathy was performed using a questionnaire, by neurological tests, and by vibration threshold (VT) measurements. Because VT determination gives the most objective information, VT measurements were used for further analyses.

RESULTS AND DISCUSSION

The analyses revealed that neuropathy of the hands was related to follow-up time, with an observed recovery half-life of 6.8 (+/- 3.1) years. No significant reversibility of neuropathy of the feet within the observation period could be demonstrated. For cisplatin, the severity of neuropathy was related to the cumulative dose and sodium thiosulfate use. Oxaliplatin induced neuropathy did not appear to be related to the dose within the studied dose range. No relationship with platinum levels, renal function, glutathione transferase genotypes, diabetes mellitus, alcohol use, or co-medication could be demonstrated. This study was performed as an explorative study and the issues discussed need to be investigated further.

Oxaliplatin-induced neurotoxicity: changes in axonal excitability precede development of neuropathy

Administration of oxaliplatin, a platinum-based chemotherapy used extensively in the treatment of colorectal cancer, is complicated by prominent dose-limiting neurotoxicity. Acute neurotoxicity develops following oxaliplatin infusion and resolves within days, while chronic neuropathy develops progressively with higher cumulative doses. To investigate the pathophysiology of oxaliplatin-induced neurotoxicity and neuropathy, clinical grading scales, nerve conduction studies and a total of 905 axonal excitability studies were undertaken in a cohort of 58 consecutive oxaliplatin-treated patients. Acutely following individual oxaliplatin infusions, significant changes were evident in both sensory and motor axons in recovery cycle parameters (P < 0.05), consistent with the development of a functional channelopathy of axonal sodium channels. Longitudinally across treatment (cumulative oxaliplatin dose 776 +/- 46 mg/m(2)), progressive abnormalities developed in sensory axons (refractoriness P < or = 0.001; superexcitability P < 0.001; hyperpolarizing threshold electrotonus 90-100 ms P < or = 0.001), while motor axonal excitability remained unchanged (P > 0.05), consistent with the purely sensory symptoms of chronic oxaliplatin-induced neuropathy. Sensory abnormalities occurred prior to significant reduction in compound sensory amplitude and the development of neuropathy (P < 0.01). Sensory excitability abnormalities that developed during early treatment cycles (cumulative dose 294 +/- 16 mg/m(2) oxaliplatin; P < 0.05) were able to predict final clinical outcome on an individual patient basis in 80% of patients. As such, sensory axonal excitability techniques may provide a means to identify pre-clinical oxaliplatin-induced nerve dysfunction prior to the onset of chronic neuropathy. Furthermore, patients with severe neurotoxicity at treatment completion demonstrated greater excitability changes (P < 0.05) than those left with mild or moderate neurotoxicity, suggesting that assessment of sensory excitability parameters may provide a sensitive biomarker of severity for oxaliplatin-induced neurotoxicity.

Erythropoietin overrides the triggering effect of DNA platination products in a mouse model of cisplatin-induced neuropathy

BACKGROUND

Cisplatin mediates its antineoplastic activity by formation of distinct DNA intrastrand cross links. The clinical efficacy and desirable dose escalations of cisplatin are restricted by the accumulation of DNA lesions in dorsal root ganglion (DRG) cells leading to sensory polyneuropathy (PNP). We investigated in a mouse model by which mechanism recombinant erythropoietin (rhEPO) protects the peripheral nervous system from structural and functional damage caused by cisplatin treatment with special emphasis on DNA damage burden.

RESULTS

A cumulative dose of 16 mg cisplatin/kg resulted in clear electrophysiological signs of neuropathy, which were significantly attenuated by concomitant erythropoietin (cisplatin 32,48 m/s +/- 1,68 m/s; cisplatin + rhEPO 49,66 m/s +/- 1,26 m/s; control 55,01 m/s +/- 1,88 m/s; p < 0,001). The co-application of rhEPO, however, did not alter the level of unrepaired cisplatin-DNA lesions accumulating in DRG target cells. Micro-morphological analyses of the sciatic nerve from cisplatin-exposed mice showed damaged myelin sheaths and mitochondria. Co-administered rhEPO inhibited myelin sheaths from structural injuries and resulted in an increased number of intact mitochondria.

CONCLUSION

The protective effect of recombinant erythropoietin is not mediated by reducing the burden of DNA platination in the target cells, but it is likely to be due to a higher resistance of the target cells to the adverse effect of DNA damage. The increased frequency of intact mitochondria might also contribute to this protective role.

Mice with cisplatin and oxaliplatin-induced painful neuropathy develop distinct early responses to thermal stimuli

Background

Cisplatin has been in use for 40 years for treatment of germ line and other forms of cancer. Oxaliplatin is approved for treatment of metastatic colorectal cancer. Thirty to forty percent of cancer patients receiving these agents develop pain and sensory loss. Oxaliplatin induces distinctive cold-associated dysesthesias in up to 80% of patients.

Results

We have established mouse models of cisplatin and oxaliplatin-induced neuropathy using doses similar to those used in patients. Adult male C57BL6J mice were treated with daily intraperitoneal injection for 5 days, followed by 5 days of rest, for two cycles. Total cumulative doses of 23 mg/kg cisplatin and 30 mg/kg oxaliplatin were used. Behavioral evaluations included cold plate, von Frey, radiant heat, tail immersion, grip strength and exploratory behavior at baseline and at weekly intervals for 8 weeks. Following two treatment cycles, mice in the cisplatin and oxaliplatin treatment groups demonstrated significant mechanical allodynia compared to control mice. In addition, the cisplatin group exhibited significant thermal hyperalgesia in hind paws and tail, and the oxaliplatin group developed significant cold hyperalgesia in hind paws.

Conclusion

We have therefore established a model of platinum drug-induced painful peripheral neuropathy that reflects the differences in early thermal pain responses that are observed in patients treated with either cisplatin or oxaliplatin. This model should be useful in studying the molecular basis for these different pain responses and in designing protective therapeutic strategies.

Chemotherapy-induced peripheral neuropathy: prevention and treatment strategies

Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose limiting side effect of many commonly used chemotherapeutic agents, including platinum drugs, taxanes, epothilones and vinca alkaloids, and also newer agents such as bortezomib and lenolidamide. Symptom control studies have been conducted looking at ways to prevent or alleviate established CIPN. This manuscript provides a review of studies directed at both of these areas. New evidence strongly suggests that intravenous calcium and magnesium therapy can attenuate the development of oxaliplatin-induced CIPN, without reducing treatment response. Accumulating data suggest that vitamin E may also attenuate the development of CIPN, but more data regarding its efficacy and safety should be obtained prior to its general use in patients. Other agents that look promising in preliminary studies, but need substantiation, include glutamine, glutathione, N-acetylcysteine, oxcarbazepine, and xaliproden. Effective treatment of established CIPN, however, has yet to be found. Lastly, paclitaxel causes a unique acute pain syndrome which has been hypothesised to be caused by neurologic injury. No drugs, to date, have been proven to prevent this toxicity.