Neurological complications of cancer chemotherapy

Huangqi Guizhi Wuwu decoction alleviates oxaliplatin-induced peripheral neuropathy via the gut-peripheral nerve axis

BACKGROUND

Oxaliplatin-induced peripheral neurotoxicity (OIPN) limits the dose of chemotherapy and seriously affects the quality of life. Huangqi Guizhi Wuwu Decoction (HGWD) is a classical Traditional Chinese Medicine (TCM) formula for the prevention of OIPN. However, its specific pharmacological mechanism of action remains unknown. Our study found that HGWD can effectively alleviate chronic OIPN and regulate intestinal flora. Therefore, we explored the mechanism of action of HGWD in alleviating chronic OIPN from the perspective of intestinal flora.

METHODS

In this study, we established an OIPN model in C57BL/6 mice treated with different concentrations of HGWD. Mechanical pain and cold pain were assessed at certain time points, and samples of mice colon, dorsal root ganglion (DRG), serum, and feces were collected. Associated inflammation levels in the colon and DRG were detected using immunohistochemical techniques; the serum lipopolysaccharide (LPS) levels and associated inflammation were assessed using the appropriate kits; and 16S rRNA sequencing was used to examine the dynamic changes in gut microorganisms. Finally, established fecal microbiota transplantation (FMT) and antibiotic (ABX) pretreatment models were used to validate flora's role in HGWD for chronic OIPN by pain scoring and related pathological analysis.

RESULTS

HGWD treatment significantly alleviated pain sensitivity in chronic OIPN mice. Pathological results showed that HGWD treatment improved intestinal ZO-1 expression and reduced serum LPS levels and associated inflammatory factors in the colon, serum, and DRG. The 16S rRNA results showed that HGWD restored the composition of the intestinal flora in a time-dependent manner to alleviate OIPN. FMT and ABX experiments demonstrated that HGWD can alleviate chronic OIPN by regulating intestinal flora homeostasis.

CONCLUSIONS

HGWD prevents chronic OIPN by dynamically regulating intestinal flora homeostasis, thereby ameliorating intestinal barrier damage and reducing serum LPS and relevant inflammatory factor levels in the colon, serum, and DRG.

Cisplatin-induced neurotoxicity involves the disruption of serotonergic neurotransmission

Neurotoxicity is a frequent side effect of cisplatin (CisPt)-based anticancer therapy whose pathophysiology is largely vague. Here, we exploited C. elegans as a 3R-compliant in vivo model to elucidate molecular mechanisms contributing to CisPt-induced neuronal dysfunction. To this end, we monitored the impact of CisPt on various sensory functions as well as pharyngeal neurotransmission by recording electropharyngeograms (EPGs). CisPt neither affected food and odor sensation nor mechano-sensation, which involve dopaminergic and glutaminergic neurotransmission. However, CisPt reduced serotonin-regulated pharyngeal pumping activity independent of changes in the morphology of related neurons. CisPt-mediated alterations in EPGs were fully rescued by addition of serotonin (5-HT) (≤ 2 mM). Moreover, the CisPt-induced pharyngeal injury was prevented by co-incubation with the clinically approved serotonin re-uptake inhibitory drug duloxetine. A protective effect of 5-HT was also observed with respect to CisPt-mediated impairment of another 5-HT-dependent process, the egg laying activity. Importantly, CisPt-induced apoptosis in the gonad and learning disability were not influenced by 5-HT. Using different C. elegans mutants we found that CisPt-mediated (neuro)toxicity is independent of serotonin biosynthesis and re-uptake and likely involves serotonin-receptor subtype 7 (SER-7)-related functions. In conclusion, by measuring EPGs as a surrogate parameter of neuronal dysfunction, we provide first evidence that CisPt-induced neurotoxicity in C. elegans involves 5-HT-dependent neurotransmission and SER-7-mediated signaling mechanisms and can be prevented by the clinically approved antidepressant duloxetine. The data highlight the particular suitability of C. elegans as a 3R-conform in vivo model in molecular (neuro)toxicology and, moreover, for the pre-clinical identification of neuroprotective candidate drugs.

Cold Application and Exercise on Development of Peripheral Neuropathy during Taxane Chemotherapy in Breast Cancer Patients: A Randomized Controlled Trial

Objective

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. There is no proven pharmacological application to prevent CIPN. This study was conducted to compare the effects of cold application and exercise on peripheral neuropathy development in patients with breast cancer who received taxane.

Methods

This was a multicenter clinical trial. The study was conducted as a randomized controlled trial on breast cancer patients who had chemotherapy-induced peripheral neuropathy complaints between July 2017 and January 2018 in an outpatient chemotherapy unit of training-research and a university hospital. A standardized, home-based, 12-week exercise program involved progressive strengthening, stretching, and balance exercises. Cold packs were applied for the duration of all 12 taxane infusions and then continued at home. The standard care protocol (information about side effects) of the clinic was used for patients in the control group. Data were collected via Patient Identification Form and CIPN Assessment Tool. Demographic data were evaluated by number and percentage ratios, and the study groups' mean scores were compared by Kruskal-Wallis and Wilcoxon analyses. The data were collected at two time points including baseline (T1) and week 12 (T2).

Results

The study was completed with a total of 90 patients, so that each of the study groups, exercise, cold application, and control groups, included 30 patients. The mean of pre- and posttest results in the cold applied group revealed an increase in hand numbness, weakness, and distress (P < 0.05). However, no significant difference existed between the means of the pre- and the posttests in the exercise group (P = 0.79-0.1). The mean scores of all the symptoms in the control group except the loss of balance increased significantly (P < 0.05). Exercise reduced CIPN symptoms of numbness in hands (P = 0.009) and in the feet (P = 0.005) significantly compared to the cold application and control.

Conclusions

It was found that exercise was more effective than cold application in the management of CIPN.

The Use of Imaging in the Prediction and Assessment of Cancer Treatment Toxicity

Multimodal imaging is commonly used in the management of patients with cancer. Imaging plays pivotal roles in the diagnosis, initial staging, treatment response assessment, restaging after treatment and the prognosis of many cancers. Indeed, it is difficult to imagine modern precision cancer care without the use of multimodal molecular imaging, which is advancing at a rapid pace with innovative developments in imaging sciences and an improved understanding of the complex biology of cancer. Cancer therapy often leads to undesirable toxicity, which can range from an asymptomatic subclinical state to severe end organ damage and even death. Imaging is helpful in the portrayal of the unwanted effects of cancer therapy and may assist with optimal clinical decision-making, clinical management, and overall improvements in the outcomes and quality of life for patients.

Intravenous glutamine appears to reduce the severity of symptomatic platinum-induced neuropathy: a prospective randomized study

The purpose of this study is to evaluate the efficacy of intravenous (IV) glutamine or calcium/magnesium (Ca/Mg) infusion against platinum-induced neuropathy. Patients undergoing platinum-based (oxaliplatin or cisplatin) therapy were randomized to receive IV glutamine or Ca/Mg infusion during four cycles of chemotherapy, from the fifth cycle of therapy to the eighth cycle. The total neuropathy score (TNS) was evaluated at the end of the fourth course of chemotherapy (as baseline) and at the end of the eighth cycle (as end-of treatment). The intent-to-treat analysis of the end point included 29 patients in the glutamine arm and 26 patients in the Ca/Mg arm. The mean TNS of both cohorts increased significantly. The baseline and end-of-treatment TNSs between the two groups were not statistically different. Patients with symptoms at baseline (N = 29) had significantly lower scores at the end of the study in the glutamine group (P = 0.045). Besides, glutamine group patients who initially had only sensory symptoms (N = 23) also had significantly lower scores at the study's end (P = 0.035). Neither IV glutamine nor Ca/Mg infusion prevented further worsening of platinum-induced neuropathy. However, IV glutamine apparently reduced the severity of symptomatic platinum-induced neuropathy.

Subacute reversible toxic encephalopathy related to treatment with capecitabine: a case report with literature review and discussion of pathophysiology

INTRODUCTION

Capecitabine, a 5-fluorouracil (5FU) pro-drug, is increasingly used in breast and gastrointestinal cancers due to its more convenient oral route of administration when compared to 5FU. Despite its widespread use, there are only a few reports on capecitabine CNS toxicity, while the pathogenic basis of such toxicity remains unclear.

CASE

A 69-year-old male presented with recurrent generalized seizures 2.5 months after preoperative chemoradiotherapy with capecitabine in locally advanced rectal cancer. Brain MRI revealed a diffuse, subcortical white matter alteration suggestive of vasogenic edema. The diagnosis of toxic encephalopathy was supported after elimination of alternative causes of the neurological dysfunction and complete resolution of clinical and imaging findings after 3 months of no further chemotherapy.

CONCLUSIONS

Given the expanding use of capecitabine, physicians should be aware of this potential complication when a neurological worsening occurs during or after treatment with this chemotherapeutic agent. In our case, as in previously described cases encephalopathy was characterized by a favorable course after cessation of the drug. Vasogenic edema rather than cytotoxic edema may play a pivotal pathogenetic role in this form of encephalopathy.

Anesthesia for the child with cancer

Children with cancer undergo a host of surgeries and procedures that require anesthesia during the various phases of the disease. A safe anesthetic plan includes consideration of the direct effects of tumor, toxic effects of chemotherapy and radiation therapy, the specifics of the surgical procedure, drug-drug interactions with chemotherapy agents, pain syndromes, and psychological status of the child. This article provides a comprehensive overview of the anesthetic management of the child with cancer, focuses on a systems-based approach to the impact from both tumor and its treatment in children, and presents a discussion of the relevant anesthetic considerations.

Oxidative stress and neurodegenerative disorders

Living cells continually generate reactive oxygen species (ROS) through the respiratory chain during energetic metabolism. ROS at low or moderate concentration can play important physiological roles. However, an excessive amount of ROS under oxidative stress would be extremely deleterious. The central nervous system (CNS) is particularly vulnerable to oxidative stress due to its high oxygen consumption, weakly antioxidative systems and the terminal-differentiation characteristic of neurons. Thus, oxidative stress elicits various neurodegenerative diseases. In addition, chemotherapy could result in severe side effects on the CNS and peripheral nervous system (PNS) of cancer patients, and a growing body of evidence demonstrates the involvement of ROS in drug-induced neurotoxicities as well. Therefore, development of antioxidants as neuroprotective drugs is a potentially beneficial strategy for clinical therapy. In this review, we summarize the source, balance maintenance and physiologic functions of ROS, oxidative stress and its toxic mechanisms underlying a number of neurodegenerative diseases, and the possible involvement of ROS in chemotherapy-induced toxicity to the CNS and PNS. We ultimately assess the value for antioxidants as neuroprotective drugs and provide our comments on the unmet needs.

Central neurotoxicity in cancer chemotherapy: pharmacogenetic insights

Central neurotoxicity of chemotherapy is likely to be multifactorial. There are two hypotheses regarding endogenous mechanisms that may be involved, namely the target and the blood-brain barrier transporter hypotheses. Here, we will review candidate genetic determinants for the risk of chemotherapy-induced neurotoxicity, such as polymorphisms involved in the target mechanism. These include polymorphisms in folate metabolizing enzymes and apolipoprotein E, as well as those in blood-brain barrier transporter genes. Currently, the exact role of pharmacogenetics in mechanisms that lead to central neurotoxicity of chemotherapy has not been fully unraveled. Larger, prospective, longitudinal and more uniform studies are needed, with prechemotherapy and follow-up measurements of neuropsychological performance, MRI, PET, genetic profiles and biomarkers relevant for the proposed target and transporter mechanisms.

Toxic encephalopathy in elderly patients during treatment with capecitabine: literature review and a case report

Capecitabine is now-a-days rapidly replacing 5-Fluorouracil in daily clinical practice. Neurologic toxicity during a treatment with fluoropyrimidines, as 5-fluorouracil, represents a well-known side-effect, largely described in literature. Central nervous system (CNS) toxicity, mainly encephalopathy with or without seizures, occurs occasionally even when conventional doses are used. CNS toxicity incidence increases markedly when the blood-brain barrier is either overwhelmed or bypassed (Hildebrand J. Neurological complications of cancer chemotherapy. Curr Opin Oncol 2006; 18: 321—324). Peripheral nervous system (PNS) toxicity is more common because proximal and distal extremities of the peripheral nerves are not protected by a blood-brain like barrier and peripheral neuropathy remains a major limiting factor for the administration of conventional doses of several agents (Saif W, Wood TE, McGee PJ and Diasio RB. Peripheral neuropathy associated with capecitabine, Anticancer Drugs 2004;15: 767—771). Capecitabine is a prodrug of 5-fluorouracil, more easily administered by mouth; its transformation in 5-fluorouracil is performed in the liver. There are only a few reports on the toxic neurological side-effects of capecitabine. We describe in our report a rare case of toxic encephalopathy in a 82-year-old female, with a brief review of literature.

In the literature reviewed, we found 12 neurologic episodes due to capecitabine lasting between a few days till some months. All clinical symptoms of the cases described in literature, obtained a complete regression with the discontinuation of capecitabine. A relation was not found with dihydropyrimidine dehydrogenase (DPD) mutation, also if pharmacologic and pharmacogenetic assessment should be done for this drug, especially in old patients.

Toxic encephalopathy represents a rare event during capecitabine treatment and on the bases of the data found, is fairly managed in the clinical setting. The knowledge of the natural history of the toxic effect allows the use of the drug also in old patients.

Anesthetic considerations for the pediatric oncology patient--part 2: systems-based approach to anesthesia

One of the prices paid for chemo- and radiotherapy of cancer in children is damage to the vulnerable and developing healthy tissues of the body. Such damage can exist clinically or subclinically and can become apparent during active antineoplastic treatment or during remission decades later. Furthermore, effects of the tumor itself can significantly impact the physiologic state of the child. The anesthesiologist who cares for children with cancer or for survivors of childhood cancer should understand what effects cancer and its therapy can have on various organ systems. In part two of this three-part review, we review the anesthetic issues associated with childhood cancer. Specifically, this review presents a systems-based approach to the impact from both tumor and its treatment in children, followed by a discussion of the relevant anesthetic considerations.

Bevacizumab in combination with sequential high-dose chemotherapy in solid cancer, a feasibility study

We evaluated the feasibility and toxicity of bevacizumab in combination with sequential high-dose (HD) ifosfamide, carboplatin and etoposide refractory to standard chemotherapy in patients with sarcoma and germ cell cancer (GCC). Sixteen patients (13 sarcomas, 3 GCC) received SD-ICE followed by 4 cycles of HD-ICE, qd22 with stem cell support in combination with bevacizumab. All 16 patients were evaluable for toxicity and efficacy, and received 51 cycles (median 3.3). There was no increase in toxicity except of a relatively high incidence of ifosfamide encephalopathy in 17 cycles when compared with previous HD-ICE protocols. One almost complete response in the patient with GCC, previously progressive with three preceding protocols, was observed. Six patients had a partial response (sarcoma 4/13 patients; GCC 2/3 patients), and five patients stable disease (sarcoma 5/13 patients). The median PFS/OS for sarcoma was 5 months (confidence interval (CI): 3.1-6.9) and 13 months (CI: 3.6-24.4), respectively. To our knowledge, this is the first report of the addition of bevacizumab to HD-ICE. This combination did not show new unexpected toxicities except for a relatively high rate of ifosfamide encephalopathy. The efficacy in these heavily pretreated patients including possible reversal of chemotherapy resistance by the addition of bevacizumab indicates a possible potential of bevacizumab in this combination.

Animal models of chemotherapy-evoked painful peripheral neuropathies

This review examines recent preclinical research on toxic peripheral neuropathy and potential therapeutic developments. Chemotherapy-induced peripheral neurotoxicity is a major clinical problem because it represents the dose-limiting side effects of a significant number of antineoplastic drugs. Patients are unable to complete full or optimal treatment schedules. The incidence of chemotherapy-induced peripheral neuropathy varies depending on the drugs and schedules used, and this can be quite high, particularly when neurophysiological methods are used to make a diagnosis. However, even when chemotherapy-induced peripheral neuropathy is not a dose-limiting side effect, its onset may severely affect the quality of life of cancer patients and cause chronic discomfort. As such, improved understanding of the pathophysiology of chemotherapy-induced neurotoxicity need for animal models is clinically relevant and will assist in the development of future neuroprotective strategies and also in the design of novel chemotherapies with improved toxicity profiles. In this review, the features of animal models of chemotherapy-induced painful neuropathy developed for 20 years, due to the administration of the most widely used drugs, such as platinum drugs, taxanes, and vinca alkaloids, will be discussed. In a second part, data available on neuroprotectants and treatment strategies, evaluated using these previous animal models in the attempt to prevent neuropathic pain, will be summarized.

Chemotherapy related encephalopathy in a patient with Stage IV cervical carcinoma treated with cisplatin and 5-fluorouracil: a case report

INTRODUCTION

Chemotherapy related encephalopathy is commonly reported with certain forms of chemotherapy but few reports note an association with low dose 5-Fluorouracil.

CASE PRESENTATION

A 57-year-old Caucasian lady received her first cycle of Cisplatin and 5-Fluorouracil for palliative treatment of cervical carcinoma, and presented several days later with signs of encephalopathy. Several causes were eliminated, and encephalopathy related to 5-Fluorouracil was thought to be the most likely cause. Magnetic Resonance Imaging of the head revealed changes related to the chemotherapy received. Symptoms resolved completely within three days of presentation.

CONCLUSION

Encephalopathy from low dose 5-Fluorouracil is not well documented in the literature. Fluid rehydration and supportive treatment is required. Signs and symptoms resolved completely with no residual effects on follow up.

Encephalopathy secondary to capecitabine chemotherapy: a case report and discussion

Introduction. Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) chemotherapy and is licenced for the treatment of breast and gastrointestinal cancers. Multifocal inflammatory leukoencephalopathy has been associated with intravenous 5-FU, but only a few cases of capecitabine-induced encephalopathy have been reported.

Setting. We describe here a case of encephalopathy following administration of Epirubicin/ Cisplatin/Capecitabine chemotherapy, review those cases previously described and suggest recommendations for management.

Results. Symptoms of neurotoxicity from 5-FU and capecitabine usually include confusion, ataxia, nystagmus, dysarthria, sensory loss, and memory loss. Withdrawal of the drug generally leads to improvement of symptoms and steroids are of only questionable benefit.

Conclusion. Patients on fluouropyrimidine drugs with new neurological symptoms should be investigated with brain MRI scan and the drug should be withdrawn until symptoms resolve. Dihydropyrimidine dehydrogenase deficiency should be excluded and ideally an alternative chemotherapy regime sought. We would encourage reporting of such incidences to gain a clearer picture of the incidence and optimal management. J Oncol Pharm Practice (2009) 15: 237—239.

Therapy of chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is still a common and disabling side effect of many chemotherapy agents in use today. Unfortunately, neither prophylactic strategies nor symptomatic treatments have proven useful yet. This review will discuss the diagnosis and evaluation of neuropathy in cancer patients, as well as reviewing the various prophylactic and symptomatic treatments that have been proposed or tried. However, sufficient evidence is lacking to recommend any of these treatments to patients suffering with CIPN. Therefore, the best approach is to treat symptomatically, and to start with broad-spectrum analgesic medications such as non-steroidal anti-inflammatory drugs (NSAIDs). If NSAIDs fail, a reasonable second-line agent in properly selected patients may be an opioid. Unfortunately, even when effective in other types of neuropathic pain, anti-depressants and anticonvulsants have not yet proven effective for treating the symptoms of CIPN.

Chemotherapy-induced neuropathy

Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.

Apoptotic pathway induced by noscapine in human myelogenous leukemic cells

It has been shown that noscapine, an opium-derived phthalideisoquinoline alkaloid that is currently being used as an oral antitussive drug, induces apoptosis in myeloid leukemia cells. The molecular mechanism responsible for the anticancer effects of noscapine is poorly understood. In the current study, the apoptotic effects of noscapine on two myeloid cell lines, apoptosis-proficient HL60 cells and apoptosis-resistant K562 cells, were analyzed. An increase in the activity of caspase-2, -3, -6, -8 and -9, poly(ADP ribose) polymerase cleavage, detection of phosphatidylserine on the outer layer of the cell membrane, nucleation of chromatin, and DNA fragmentation suggested the induction of apoptosis. Noscapine increased the Bax/Bcl-2 ratio with a significant decrease of Bcl-2 expression accompanied with Bcl-2 phosphorylation. Using an inhibitory approach, the activation of the caspase cascade involved in the noscapine-induced apoptosis was analyzed. We observed no inhibitory effect of the caspase-8 inhibitor on caspase-9 activity. In view of these results and taking into consideration that K562 cells are Fas-null, we suggested that caspase-8 is activated in a Fas-independent manner downstream of caspase-9. In conclusion, noscapine can induce apoptosis in both apoptosis-proficient and apoptosis-resistant leukemic cells, and it can be a novel candidate in the treatment of hematological malignancies.