Neurotoxic complications of chemotherapy in patients with cancer: clinical signs and optimal management

Neurosteroid 3α-androstanediol efficiently counteracts paclitaxel-induced peripheral neuropathy and painful symptoms

Painful peripheral neuropathy belongs to major side-effects limiting cancer chemotherapy. Paclitaxel, widely used to treat several cancers, induces neurological symptoms including burning pain, allodynia, hyperalgesia and numbness. Therefore, identification of drugs that may effectively counteract paclitaxel-induced neuropathic symptoms is crucial. Here, we combined histopathological, neurochemical, behavioral and electrophysiological methods to investigate the natural neurosteroid 3α-androstanediol (3α-DIOL) ability to counteract paclitaxel-evoked peripheral nerve tissue damages and neurological symptoms. Prophylactic or corrective 3α-DIOL treatment (4 mg/kg/2days) prevented or suppressed PAC-evoked heat-thermal hyperalgesia, cold-allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased thermal and mechanical pain thresholds of PAC-treated rats. Electrophysiological studies demonstrated that 3α-DIOL restored control values of nerve conduction velocity and action potential peak amplitude significantly altered by PAC-treatment. 3α-DIOL also repaired PAC-induced nerve damages by restoring normal neurofilament-200 level in peripheral axons and control amount of 2’,3’-cyclic-nucleotide-3’-phosphodiesterase in myelin sheaths. Decreased density of intraepidermal nerve fibers evoked by PAC-therapy was also counteracted by 3α-DIOL treatment. More importantly, 3α-DIOL beneficial effects were not sedation-dependent but resulted from its neuroprotective ability, nerve tissue repairing capacity and long-term analgesic action. Altogether, our results showing that 3α-DIOL efficiently counteracted PAC-evoked painful symptoms, also offer interesting possibilities to develop neurosteroid-based strategies against chemotherapy-induced peripheral neuropathy. This article shows that the prophylactic or corrective treatment with 3α-androstanediol prevents or suppresses PAC-evoked painful symptoms and peripheral nerve dysfunctions in rats. The data suggest that 3α-androstanediol-based therapy may constitute an efficient strategy to explore in humans for the eradication of chemotherapy-induced peripheral neuropathy.

[Organ toxicity of medicinal tumor therapy: morphological correlates]

CLINICAL/METHODOLOGICAL ISSUE: In antineoplastic chemotherapy classical cytostatic drugs are increasingly being supplemented by antibodies and so-called targeted therapies. In addition to the antineoplastic effect and general intolerance quite characteristic morphological changes can often be found and identified by the radiologist. The distinction between findings indicating side effects versus tumor progression or an infectious etiology is essential.

FACTS AND CIRCUMSTANCES

Classical antineoplastic chemotherapy interacts with DNA and RNA synthesis, DNA repair or the mitosis process. In contrast modern targeted anticancer therapies act at the level of signal transduction pathways.Localized, organ-related changes are related to the metabolic characteristics of organs or anatomical features such as the properties of the local blood-tissue barrier. Toxicity associated findings often resemble fulminant tumor progression.

EVALUATION

In new targeted anti-cancer therapies toxicity often occurs in a non-cumulative way; therefore, morphological changes are often precursors of the manifestation of clinical toxicity.

PRACTICAL RECOMMENDATIONS

Oncological radiology requires increasingly active interdisciplinary dialogue in order to delineate morphological correlates of organ toxicity against tumor progression and initiate appropriate therapeutic measures.

New approaches to understand cognitive changes associated with chemotherapy for non-central nervous system tumors

CONTEXT

Researchers have described a constellation of cognitive deficits (e.g., impairments in executive functions, working memory, attention, and information-processing speed) associated with cancer treatment, and specifically chemotherapy, for non-central nervous system tumors. However, findings have been inconsistent, largely because of measurement and study design issues.

OBJECTIVES

To propose ways for researchers to more clearly delineate and characterize the mild cognitive deficits and related outcomes that appear to affect a subset of cancer patients and suggest methods to make more effective use of the existing data to understand risk factors for impaired neuropsychological functioning.

METHODS

We examined the literature on the relationship between chemotherapy and cognitive impairment, as well as related literature on neuropsychological measurement, structural and functional neuroimaging, alternative measures of health outcomes, and integrative data analysis.

RESULTS

A more comprehensive picture of cognitive functioning might be obtained by incorporating nontraditional ecological measures, self-reports, computational modeling, new neuroimaging methods, and markers of occupational functioning. Case-control and integrative data analytic techniques potentially could leverage existing data to identify risk factors for cognitive dysfunction and test hypotheses about the etiology of these effects.

CONCLUSION

There is a need to apply new research approaches to understand the real-world functional implications of the cognitive side effects of chemotherapy to develop and implement strategies to minimize and remediate these effects before, during, and after cancer treatment.

Comparison of two chemotherapy-induced peripheral neuropathy measurement approaches in children

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment in children; however, measurement of CIPN has been hampered by limitations in available tools, which may impact prevalence estimates. The purpose of this study was to assess the relative ability of the Common Terminology Criteria (CTCAE) rating process to detect sensory and motor neuropathy as compared to administration of the pediatric modified Total Neuropathy Score (peds-mTNS).

METHODS

The ped-mTNS was administered to 60 children/adolescents ages 5-18 undergoing treatment for acute lymphocytic leukemia, lymphoma, or non-CNS solid tumors. CTCAE v3.0 scores for the same time point were abstracted from the medical record by a separate trained rater. Comparisons were made between scores using descriptive statistics, correlations, and specificity and sensitivity calculations.

RESULTS

The median ped-mTNS score was 9 (32 possible), while the median sensory and motor CTCAE ratings were 0 and 2, respectively (4 and 5 possible, respectively). There was no correlation between ped-mTNS and combined sensory and motor CTCAE scores. The only ped-mTNS item with significant correlation to CTCAE scoring was strength testing. Medical record abstraction of CTCAE scores failed to identify sensory neuropathy in 40 % and significant motor neuropathy (manual muscle test grade 3 or worse) in 15 % of subjects.

CONCLUSIONS

Prospective measures of CIPN using the ped-mTNS identified a far greater proportion of subjects with peripheral neurotoxicity as compared to CTCAE v3.0 sensory and motor neuropathy ratings, and thus we recommend the use of a specific measure of CIPN such as the ped-mTNS.

Inhibition of cisplatin-induced lipid catabolism and weight loss by ghrelin in male mice

Cachexia, defined as an involuntary weight loss ≥ 5%, is a serious and dose-limiting side effect of chemotherapy that decreases survival in cancer patients. Alterations in lipid metabolism are thought to cause the lipodystrophy commonly associated with cachexia. Ghrelin has been proposed to ameliorate the alterations in lipid metabolism due to its orexigenic and anabolic properties. However, the mechanisms of action through which ghrelin could potentially ameliorate chemotherapy-associated cachexia have not been elucidated. The objectives of this study were to identify mechanisms by which the chemotherapeutic agent cisplatin alters lipid metabolism and to establish the role of ghrelin in reversing cachexia. Cisplatin-induced weight and fat loss were prevented by ghrelin. Cisplatin increased markers of lipolysis in white adipose tissue (WAT) and of β-oxidation in liver and WAT and suppressed lipogenesis in liver, WAT, and muscle. Ghrelin prevented the imbalance between lipolysis, β-oxidation, and lipogenesis in WAT and muscle. Pair-feeding experiments demonstrated that the effects of cisplatin and ghrelin on lipogenesis, but not on lipolysis and β-oxidation, were due to a reduction in food intake. Thus, ghrelin prevents cisplatin-induced weight and fat loss by restoring adipose tissue functionality. An increase in caloric intake further enhances the anabolic effects of ghrelin.

Chemotherapy-induced neuropathy and its association with quality of life among 2- to 11-year colorectal cancer survivors: results from the population-based PROFILES registry

PURPOSE

To gain insight into the prevalence and severity of chemotherapy-induced neuropathy and its influence on health-related quality of life (HRQOL) in a population-based sample of colorectal cancer (CRC) survivors 2 to 11 years after diagnosis.

METHODS

All alive individuals diagnosed with CRC between 2000 and 2009 as registered by the Dutch population-based Eindhoven Cancer Registry were eligible for participation. Eighty-three percent (n = 1,643) of patients filled out the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) C30 and the EORTC QLQ Chemotherapy-Induced Peripheral Neuropathy 20.

RESULTS

The five neuropathy subscale-related symptoms that bothered patients with CRC the most during the past week were erectile problems (42% of men), trouble hearing (11%), trouble opening jars or bottles (11%), tingling toes/feet (10%), and trouble walking stairs or standing up (9%). Additionally, patients who received oxaliplatin more often reported tingling (29% v 8%; P = .001), numbness (17% v 5%; P = .005), and aching or burning pain (13% v 6%; P = .03) in toes/feet compared with those not treated with chemotherapy. They also more often reported tingling toes/feet (29% v 14%; P = .0127) compared with those treated with chemotherapy without oxaliplatin. Those with many neuropathy symptoms (eg, upper 10%) reported statistically significant and clinically relevant worse HRQOL scores on all EORTC QLQ-C30 subscales (all P < .01).

CONCLUSION

Two to 11 years after diagnosis of CRC, neuropathy-related symptoms are still reported, especially sensory symptoms in the lower extremities among those treated with oxaliplatin. Because neuropathy symptoms have a negative influence on HRQOL, these should be screened for and alleviated. Future studies should focus on prevention and relief of chemotherapy-induced neuropathy.

The future of NMR metabolomics in cancer therapy: towards personalizing treatment and developing targeted drugs?

There has been a recent shift in how cancers are defined, where tumors are no longer simply classified by their tissue origin, but also by their molecular characteristics. Furthermore, personalized medicine has become a popular term and it could start to play an important role in future medical care. However, today, a "one size fits all" approach is still the most common form of cancer treatment. In this mini-review paper, we report on the role of nuclear magnetic resonance (NMR) metabolomics in drug development and in personalized medicine. NMR spectroscopy has successfully been used to evaluate current and potential therapies, both single-agents and combination therapies, to analyze toxicology, optimal dose, resistance, sensitivity, and biological mechanisms. It can also provide biological insight on tumor subtypes and their different responses to drugs, and indicate which patients are most likely to experience off-target effects and predict characteristics for treatment efficacy. Identifying pre-treatment metabolic profiles that correlate to these events could significantly improve how we view and treat tumors. We also briefly discuss several targeted cancer drugs that have been studied by metabolomics. We conclude that NMR technology provides a key platform in metabolomics that is well-positioned to play a crucial role in realizing the ultimate goal of better tailored cancer medicine.

Why, After Chemotherapy, is it Necessary to Assess Memory Using Translational Testing?

As the number of cancer survivors rises, so does the importance of understanding what happens post-chemotherapy. The evidence is clear that chemotherapy affects not only cancer cells, but also healthy cells including neurons, leading to long-term cognitive dysfunction in a large portion of survivors. In order to understand the mechanism of action and in the hope of reducing the potential neurocognitive side effects of chemotherapy, pre-clinical testing should be used more effectively. However, the field is lacking translation from clinical studies to animal models. Spatial learning and memory paradigms based on the water maze, the most commonly used rodent model, are available for translational testing in humans and could overcome this weakness. There is an overwhelming need in the field to understand whether the water maze is an adequate model for post-chemotherapy impairments or whether other paradigms should be used. This is of great importance for the understanding of the mechanisms, side effects of new drugs, appropriate pharmacotherapy, and confounding factors related to chemotherapy treatment regiments. This review is very important to both basic scientists and clinicians determining how translational paradigms are critical to future cancer research, as well as what type of paradigms are appropriate in our technically advancing society.

Alterations in endocannabinoid tone following chemotherapy-induced peripheral neuropathy: effects of endocannabinoid deactivation inhibitors targeting fatty-acid amide hydrolase and monoacylglycerol lipase in comparison to reference analgesics following cisplatin treatment

Cisplatin, a platinum-derived chemotherapeutic agent, produces mechanical and coldallodynia reminiscent of chemotherapy-induced neuropathy in humans. The endocannabinoid system represents a novel target for analgesic drug development. The endocannabinoid signaling system consists of endocannabinoids (e.g. anandamide (AEA) and 2-arachidonoylglycerol (2-AG)), cannabinoid receptors (e.g. CB(1) and CB(2)) and the enzymes controlling endocannabinoid synthesis and degradation. AEA is hydrolyzed by fatty-acid amide hydrolase (FAAH) whereas 2-AG is hydrolyzed primarily by monoacylglycerol lipase (MGL). We compared effects of brain permeant (URB597) and impermeant (URB937) inhibitors of FAAH with an irreversible inhibitor of MGL (JZL184) on cisplatin-evoked behavioral hypersensitivities. Endocannabinoid modulators were compared with agents used clinically to treat neuropathy (i.e. the opioid analgesic morphine, the anticonvulsant gabapentin and the tricyclic antidepressant amitriptyline). Cisplatin produced robust mechanical and cold allodynia but did not alter responsiveness to heat. After neuropathy was fully established, groups received acute intraperitoneal (i.p.) injections of vehicle, amitriptyline (30 mg/kg), gabapentin (100 mg/kg), morphine (6 mg/kg), URB597 (0.1 or 1 mg/kg), URB937 (0.1 or 1 mg/kg) or JZL184 (1, 3 or 8 mg/kg). Pharmacological specificity was assessed by coadministering each endocannabinoid modulator with either a CB(1) (AM251 3 mg/kg), CB(2) (AM630 3 mg/kg), TRPV1 (AMG9810 3 mg/kg) or TRPA1 (HC030031 8 mg/kg) antagonist. Effects of cisplatin on endocannabinoid levels and transcription of receptors (CB(1), CB(2), TRPV1, TRPA1) and enzymes (FAAH, MGL) linked to the endocannabinoid system were also assessed. URB597, URB937, JZL184 and morphine reversed cisplatin-evoked mechanical and cold allodynia to pre-cisplatin levels. By contrast, gabapentin only partially reversed the observed allodynia while amitriptyline, administered acutely, was ineffective. CB(1) or CB(2) antagonists completely blocked the anti-allodynic effects of both FAAH (URB597, URB937) and MGL (JZL184) inhibitors to mechanical and cold stimulation. By contrast, the TRPV1 antagonist AMG9810 blocked the anti-allodynic efficacy of both FAAH inhibitors, but not the MGL inhibitor. By contrast, the TRPA1 antagonist HC30031 did not attenuate anti-allodynic efficacy of any endocannabinoid modulator. When the levels of endocannabinoids were examined, cisplatin increased both anandamide (AEA) and 2-arachidonoylglycerol (2-AG) levels in the lumbar spinal cord and decreased 2-AG levels (but not AEA) in dorsal hind paw skin. RT-PCR showed that mRNA for FAAH, but not other markers, was upregulated by cisplatin treatment in lumbar spinal cord. The present studies demonstrate that cisplatin alters endocannabinoid tone and that inhibition of endocannabinoid hydrolysis alleviates chemotherapy-induced mechanical and cold allodynia. The anti-allodynic effects of FAAH and MGL inhibitors are mediated by CB(1) and CB(2) cannabinoid receptors, whereas TRPV1, but not TRPA1, -dependent mechanisms contribute to the anti-allodynic efficacy of FAAH (but not MGL) inhibitors. Strikingly, endocannabinoid modulators potently suppressed cisplatin-evoked allodynia with a rapid onset and showed efficacy that equaled or exceeded that of major classes of anti-neuropathic pain medications used clinically. Thus, inhibition of endocannabinoid hydrolysis, via FAAH or MGL inhibitors, represents an efficacious pharmacological approach for suppressing chemotherapy-induced neuropathic pain.

Rehabilitation for ataxia following chemotherapy for burkitt lymphoma involving the rectum

Burkitt lymphoma is a type of B-cell lymphoma that occurs mostly in children, and rarely in adults. The sporadic type is known to occur mostly at the ileum and cecum. Cytarabine, which is used for central nervous system prophylaxis during chemotherapy for Burkitt lymphoma, has known neurotoxicity, and its side effects include motor ataxia due to cerebellar injury, ataxic dysarthria, dysfunction of ocular movement, confusion, somnolence and lethargy. This case report is about a patient diagnosed with Burkitt lymphoma who manifested motor ataxia after chemotherapy that included cytarabine.

Painful decisions for senior pets

Osteoarthritis and cancer are the inevitable consequences of aging and significantly contribute to the cause of death in cats and dogs. Managing the pain associated with these disease states is the veterinarian’s mandate. Many treatment modalities and agents are available for patient management; however, it is only with an understanding of disease neurobiology and a mechanism-based approach to problem diagnosis that the clinician can offer patients an optimal quality of life based on evidence-based best medicine. When treating pain, knowledge is still our best weapon.

Neurologic complications of cancer drug therapies

PURPOSE OF REVIEW

The purpose of this article is to review neurologic complications associated with systemic anticancer therapies.

RECENT FINDINGS

Although neurologic complications from traditional chemotherapies are well described, most neurologists are less familiar with complications from agents that target specific pathways or receptors. This article also reviews the most common neurologic adverse effects associated with newer targeted agents.

SUMMARY

Patients with cancer are living longer because of earlier diagnoses and remarkable improvements in treatments. Unfortunately, both traditional chemotherapies and newer targeted agents are known to cause neurologic symptoms that can impact quality of life and play a role in limiting potential treatments. Acute, subacute, and chronic syndromes may affect the central or peripheral nervous system. Since treatments for therapy-induced neurotoxicity are limited, awareness of common neurologic complications is important to prevent permanent damage.

Mesoporous Silica Nanoparticles: Their Projection in Nanomedicine

Mesoporous silica nanoparticles are receiving growing attention by the scientific biomedical community. Among the different types of inorganic nanomaterials, mesoporous silica nanoparticles have emerged as promising multifunctional platforms for nanomedicine. Since their introduction in the drug delivery landscape in 2001, mesoporous materials for drug delivery are receiving growing scientific interest for their potential applications in the biotechnology and nanomedicine fields. The ceramic matrix efficiently protects entrapped guest molecules against enzymatic degradation or denaturation induced by pH and temperature as no swelling or porosity changes take place as a response to variations in the surrounding medium. It is possible to load huge amounts of cargo into the mesopore voids and capping the pore entrances with different nanogates. The application of a stimulus provokes the nanocap removal and triggers the departure of the cargo. This strategy permits the design of stimuli-responsive drug delivery nanodevices.

Central nervous system chemotoxicity during treatment of pediatric acute lymphoblastic leukemia/lymphoma

In the last decades, increasing success rates are being obtained in the chemotherapy of pediatric leukemia and lymphoma. However, the cornerstone of this treatment is still formed by a reduced number of drugs with a highly toxic profile. In particular, central nervous system complications remain a challenging clinical problem, requiring rapid detection and prompt treatment to limit permanent damage. Furthermore, clinicians are often challenged to discriminate between CNS involvement by the disease, toxicity of drugs or infections. This clinically oriented review will help recognize and handle the main neurologic adverse effects induced by chemotherapy in pediatric patients with lymphoblastic leukemia/lymphoma. Different clinical entities and putative drugs involved are discussed in each chapter, with clinical cases illustrating the most relevant and challenging events. In addition, specific clinical-radiological patterns of some of these neurologic events are detailed. Finally, the role of pharmacogenetics, with special focus on those polymorphisms that could help explain the occurrence of neurotoxicity, is also discussed.

Discovering cytokines as targets for chemotherapy-induced painful peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN), a dose-limiting neurotoxic effect of chemotherapy, is the most common reason for early cessation of cancer treatment. This can result in an increased risk of recurrence and decreased survival rate. Inflammatory cascade activation, proinflammatory cytokine upregulation, and neuro-immune communication pathways play essential roles in the initiation and progression of CIPN. Most notably, TNF-α, IL-1β, IL-6, and CCL2 are involved in neuropathic pain. Further elucidation of the role of these cytokines could lead to their development and use as biomarkers for predicting the onset of painful peripheral neuropathy and early axonal damage. In this review, we provide evidence for the involvement of cytokines in CIPN, the possible underlying mechanisms, and their use as potential therapeutic targets and biomarkers to prevent and improve the painful peripheral neuropathy related to chemotherapeutic agents.

Síndrome mão-pé induzida por quimioterapia: relato de um caso

Objetivou-se relatar um caso de uma paciente que apresentou síndrome mão-pé de grau 3, decorrente do uso do quimioterápico Capecitabina e para a qual foi utilizada massagem local com creme hidratante aquoso à base de aloe vera. A capacidade funcional da paciente foi avaliada utilizando-se a Escala de Performance ECOG e as lesões fotografadas durante as consultas de enfermagem que ocorreram em intervalos de dez dias, totalizando quarenta dias de acompanhamento. Observou-se melhora significativa da integridade tissular, com regressão total dos sintomas, importante ganho em qualidade de vida, e retorno imediato ao tratamento quimioterápico. Acredita-se que o aloe vera pode ser um importante coadjuvante na assistência de enfermagem a pacientes submetidos à quimioterapia antineoplásica.

Healthcare costs and workloss burden of patients with chemotherapy-associated peripheral neuropathy in breast, ovarian, head and neck, and nonsmall cell lung cancer

Objective. Chemotherapy-associated peripheral neuropathy (CAPN) is a painful side-effect of chemotherapy. This study assesses healthcare and workloss costs of CAPN patients with breast, ovarian, head/neck, or non-small cell lung cancer (NSCLC) from a third-party payor/employer perspective. Research Design and Methods. Patients with qualifying tumors, and claims for chemotherapy and services indicative of peripheral neuropathy (PN) within 9-months of chemotherapy (cases) were identified in a administrative claims database. Cases were matched 1 : 1 to controls with no PN-related claims based on demographics, diabetes history and propensity for having a diagnosis of PN during the study period (based on resource use and comorbidities in a 3-month baseline period). Average all-cause healthcare costs, resource use and workloss burden were determined. Results. Average healthcare costs were $17,344 higher for CAPN cases than their non-CAPN controls, with outpatient costs being the highest component (with cases having excess costs of $8,092). On average, each CAPN case had 12 more outpatient visits than controls, and spent more days in the hospital. Workloss burden was higher for cases but not statistically different from controls. Conclusion. This study establishes that breast, ovarian, head/neck, or NSCLC patients with CAPN have significant excess healthcare costs and resource use.

Prevention of paclitaxel-induced neuropathy through activation of the central cannabinoid type 2 receptor system

BACKGROUND

Peripheral neuropathy is a major dose-limiting toxicity of chemotherapy, especially after multiple courses of paclitaxel. The development of paclitaxel-induced neuropathy is associated with the activation of microglia followed by the activation and proliferation of astrocytes, and the expression and release of proinflammatory cytokines in the spinal dorsal horn. Cannabinoid type 2 (CB(2)) receptors are expressed in the microglia in neurodegenerative disease models.

METHODS

To explore the potential of CB(2) agonists for preventing paclitaxel-induced neuropathy, we designed and synthesized a novel CB(2)-selective agonist, namely, MDA7. The effect of MDA7 in preventing paclitaxel-induced allodynia was assessed in rats and in CB(2)(+/+) and CB(2)(-/-) mice. We hypothesized that the CB(2) receptor functions in a negative-feedback loop and that early MDA7 administration can blunt the neuroinflammatory response to paclitaxel and prevent mechanical allodynia through interference with specific signaling pathways.

RESULTS

We found that MDA7 prevents paclitaxel-induced mechanical allodynia in rats and mice in a dose- and time-dependent manner without compromising paclitaxel's antineoplastic effect. MDA7's neuroprotective effect was absent in CB(2)(-/-) mice and was blocked by CB(2) antagonists, suggesting that MDA7's action directly involves CB(2) receptor activation. MDA7 treatment was found to interfere with early events in the paclitaxel-induced neuroinflammatory response as evidenced by relatively reduced toll-like receptor and CB(2) expression in the lumbar spinal cord, reduced levels of extracellular signal-regulated kinase 1/2 activity, reduced numbers of activated microglia and astrocytes, and reduced secretion of proinflammatory mediators in vivo and in in vitro models.

CONCLUSIONS

Our findings suggest an innovative therapeutic approach to prevent chemotherapy-induced neuropathy and may permit more aggressive use of active chemotherapeutic regimens with reduced long-term sequelae.

Cognitive impairments caused by oxaliplatin and 5-fluorouracil chemotherapy are ameliorated by physical activity

RATIONALE

Studies in women with breast cancer, and in animal models, have demonstrated that chemotherapy can have a negative impact on cognitive function. Which chemotherapy agents cause problems with cognition and the aetiology of the impairment is unknown. Furthermore, there is no proven treatment.

OBJECTIVES

This study aimed to evaluate the effects of 5-fluorouracil (5FU) and oxaliplatin (OX) chemotherapy agents commonly used to treat colorectal cancer on cognition in laboratory rodents. Furthermore, we assessed physical activity as a potential remedy for the observed chemotherapy-induced cognitive deficits.

RESULTS

In rodents, treatment with 5FU and OX alone impairs memory as measured by novel object recognition. But combined treatment appears to have greater detrimental effects on hippocampal-dependent tasks, contextual fear recall and spatial reference memory (water maze), yet had no effect on cued fear recall, a non-hippocampal task. These impairments were prevented by 4 weeks of wheel running overnight after 5FU/OX treatment. We found a significant interaction between chemotherapy and exercise: rats receiving both 5FU/OX and exercise had improved cognition relative to non-exercising 5FU/OX rats on novel object recognition and spatial reference memory.

CONCLUSIONS

The combination 5FU/OX had a significant impact on cognition. However, rats treated with 5FU/OX that exercised post chemotherapy had improved cognition relative to non-exercising rats. This suggests that physical activity may prove useful in ameliorating the cognitive impairments induced by 5FU/OX.

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.

Autonomic dysfunction in patients with advanced cancer; prevalence, clinical correlates and challenges in assessment

Background

The results of a small number of studies of autonomic function in patients with advanced cancer suggest that autonomic dysfunction (AD) is common. In other disease-specific groups this is associated with decreased survival, falls and symptoms such as postural hypotension, nausea, early satiety and fatigue. The contribution of AD to symptoms in advanced cancer is unknown.

Methods

We conducted a prospective cohort study designed to identify the risk factors for falls in patients with advanced cancer. Ambulant adult patients admitted consecutively to palliative care services were invited to participate. Participants underwent an assessment at baseline which included standard clinical tests of autonomic function, assessment of symptom severity, muscle strength, anthropometric measurements, walking speed, medication use, comorbidities and demographics. Information regarding survival was recorded ten months following cessation of recruitment. The clinical correlates of AD, defined as definite or severe dysfunction using Ewing's classification, were examined by univariate and multivariate logistic regression analysis. Survival analysis was conducted using Kaplan-Meier plots and the log rank test.

Results

Of 185 patients recruited, 45% were unable to complete all of the clinical tests of autonomic function. Non-completion was associated with scoring high on clinical indicators of frailty. It was possible to accurately classify 138/185 (74.6%) of participants as having either definite or severe versus normal, early or atypical AD: 110 (80%) had definite/severe AD. In logistic regression analysis, age (OR = 1.07 [95% CI; 1.03-1.1] P = 0.001) and increased severity of fatigue (OR = 1.26 [95% CI; 1.05-1.5] p = 0.016) were associated with having definite/severe AD. In analysis adjusted for age, median survival of participants with definite/severe AD was shorter than in those with normal/early/atypical classification (χ² = 4.3, p = 0.038).

Conclusions

Autonomic dysfunction is highly prevalent in patients with advanced cancer and is associated with increased severity of fatigue and reduced survival. Due to frailty, up to 45% of participants were unable to complete standard clinical tests of autonomic function. In order to further investigate the impact of AD and the therapeutic potential of treatment of AD in patients with advanced cancer, the validity of alternative novel methods of assessing autonomic function must be appraised.

Chemotherapy-induced peripheral neuropathy in pediatric cancer patients

Chemotherapy forms the backbone of treatment for many types of pediatric cancers, but a main side effect of treatment is chemotherapy-induced peripheral neuropathy (CIPN). Damage to the peripheral nervous system by chemotherapeutic agents can occur at the axon, cell body, or myelin level, and the mechanism of damage differs based on the specific chemotherapeutic agent used. This review provides background on the current knowledge of pathophysiology, assessment, and intervention for CIPN, focusing specifically on issues relevant in pediatric cancers patients. Although specific, standardized measures of CIPN are available for adults, such measures are limited for use in the pediatric populations. Likewise, clinical trials for prevention and treatment of this neuropathy and related symptoms are rare in pediatrics, but some information can be gained from the basic and adult literature.

Neuromuscular complications

Although direct neoplastic involvement of muscle tis-sue is surprisingly rare, considering the large amount of body mass that is represented by muscle tissue, the most important and unresolved muscle effect is muscle cachexia.Other associations, such as inflammatory, paraneo-plastic, toxic, and several extremely rare associations,have been described. Drug-induced toxicity and radiation recall syndrome need to be taken into consideration when muscle symptoms appear in patients with cancer.

Characterization of oxaliplatin-induced chronic painful peripheral neuropathy in the rat and comparison with the neuropathy induced by paclitaxel

Anti-neoplastic agents in the platinum-complex, taxane, vinca alkaloid, and proteasome-inhibitor classes induce a dose-limiting, chronic, distal, symmetrical, sensory peripheral neuropathy that is often accompanied by neuropathic pain. Clinical descriptions suggest that these conditions are very similar, but clinical data are insufficient to determine the degree of similarity and to determine if they share common pathophysiological mechanisms. Animal models do not have the limitations of clinical studies and so we have characterized a rat model of chronic painful peripheral neuropathy induced by a platinum-complex agent, oxaliplatin, in order to compare it with a previously characterized model of chronic painful peripheral neuropathy induced by a taxane agent, paclitaxel. The oxaliplatin model evokes mechano-allodynia, mechano-hyperalgesia, and cold-allodynia that have a delayed onset, gradually increasing severity, a distinct delay to peak severity, and duration of about 2.5 months. There is no effect on heat sensitivity. Electron microscopy (EM) analyses found no evidence for axonal degeneration in peripheral nerve, and there is no upregulation of activating transcription factor-3 in the lumbar dorsal root ganglia. There is a statistically significant loss of intraepidermal nerve fibers in the plantar hind paw skin. Oxaliplatin treatment causes a significant increase in the incidence of swollen and vacuolated mitochondria in peripheral nerve axons, but not in their Schwann cells. Nerve conduction studies found significant slowing of sensory axons, but no change in motor axons. Single fiber recordings found an abnormal incidence of A- and C-fibers with irregular, low-frequency spontaneous discharge. Prophylactic dosing with two drugs that are known to protect mitochondria, acetyl-l-carnitine and olesoxime, significantly reduced the development of pain hypersensitivity. Our results are very similar to those obtained previously with paclitaxel, and support the hypothesis that these two agents, and perhaps other chemotherapeutics, produce very similar conditions because they have a mitotoxic effect on primary afferent neurons.

Assessing the impact of chemotherapy-induced peripheral neurotoxicity on the quality of life of cancer patients: the introduction of a new measure

Purpose

To investigate the impact of chemotherapy-induced neurotoxicity on daily activities and quality of life (QoL) of cancer patients.

Methods

QoL of all patients visiting the oncological outpatient ward of the Maxima Medical Centre in the Netherlands from October 2006 until March 2007 treated with taxanes, vinca-alkaloids and/or platinum compounds (n = 88) was compared with the QoL of patients that did not receive these treatments yet (n = 43). Patient-reported neuropathy symptoms were evaluated with the newly developed Chemotherapy Induced Neurotoxicity Questionnaire (CINQ) and the Functional Assessment of Cancer Therapy/Gynaecologic Oncology Group/Neurotoxicity (FACT/GOG-Ntx) questionnaire.

Results

Patients treated with chemotherapy reported significantly more complaints of neuropathy (p < 0.001) and more paresthesias and dysesthesias in the upper (p < 0.001; p < 0.01) and lower extremities (p < 0.001) compared to those not treated with chemotherapy. They additionally experienced problems with fine motor function (e.g., getting (un)dressed, writing, and picking up small objects). Moreover, cold-induced paresthesias were frequently reported. Overall, patients indicated that their neuropathy had a negative effect on QoL.

Conclusions

The newly developed CINQ and the FACT/GOG-Ntx results suggest a considerable negative impact of patient-reported neuropathy symptoms on daily activities and QoL in cancer patients treated with chemotherapy. However, further validation of the CINQ is needed.

The T_T genotype within the NME1 promoter single nucleotide polymorphism -835 C/T is associated with an increased risk of cytarabine induced neurotoxicity in patients with acute myeloid leukemia

Recently, numerous studies have been published on inter-individual variations in the response to specific treatment with cytostatic agents such as cytarabine (Ara-C) in patients with acute myeloid leukemia (AML). Differences at the genetic level and potentially associated changes in the expression and/or function of specific drug metabolizing enzymes appear to play an important role in this inter-individual susceptibility. Single nucleotide polymorphisms (SNPs) can be easily assessed in order to further investigate and explain inter-individual differences as to Ara-C associated toxicity and response to treatment. In this retrospective study we correlated five SNPs within the NME1 promoter with drug-induced toxicity, disease-free survival and overall survival (OS) in 360 Caucasian patients suffering from AML. A significant correlation between SNPs and disease-free survival or overall survival was not found. For the NME1 promoter SNP - 835 C/T (rs2302254) we identified a significant correlation between low platelet counts and better Eastern Cooperative Oncology Group performance status (grade 3/4). An increased risk of neurotoxicity was identified for the NME1 promoter SNP - 835 C/T (rs2302254) genotype T_T. Multivariate analyses also showed that these variables were independent risk factors. Ara-C causes neuronal cell death by introduction of apoptosis with reactive oxygen species, causing oxidative DNA damage and initiating the p53-dependent apoptotic program. Recent data show that oral administration of the antioxidant N-acetylcysteine for 14 days is able to prevent Ara-C induced behavioral deficits and cellular alterations of the adult cerebellum in a rat model.

Nicotinamide inhibits alkylating agent-induced apoptotic neurodegeneration in the developing rat brain

BACKGROUND

Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain.

METHODOLOGY/PRINCIPAL FINDINGS

Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment.

CONCLUSION

Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants.

Bioceramics: from bone regeneration to cancer nanomedicine

Research on biomaterials has been growing in the last few years due to the clinical needs in organs and tissues replacement and regeneration. In addition, cancer nanomedicine has recently appeared as an effective means to combine nanotechnology developments towards a clinical application. Ceramic materials are suitable candidates to be used in the manufacturing of bone-like scaffolds. Bioceramic materials may also be designed to deliver biologically active substances aimed at repairing, maintaining, restoring or improving the function of organs and tissues in the organism. Several materials such as calcium phosphates, glasses and glass ceramics able to load and subsequently release in a controlled fashion drugs, hormones, growth factors, peptides or nucleic acids have been developed. In particular, to prevent post surgical infections bioceramics may be surface modified and loaded with certain antibiotics, thus preventing the formation of bacterial biofilms. Remarkably, mesoporous bioactive glasses have shown excellent characteristics as drug carrying bone regeneration materials. These bioceramics are not only osteoconductive and osteoproductive, but also osteoinductive, and have therefore been proposed as ideal components for the fabrication of scaffolds for bone tissue engineering. A recent promising development of bioceramic materials is related to the design of magnetic mediators against tumors. Magnetic composites are suitable thermoseeds for cancer treatment by hyperthermia. Moreover, magnetic nanomaterials offer a wide range of possibilities for diagnosis and therapy. These nanoparticles may be conjugated with therapeutic agents and heat the surrounding tissue under the action of alternating magnetic fields, enabling hyperthermia of cancer as an effective adjunct to chemotherapy regimens.

Prevalence, types, clinical associations, and determinants of peripheral neuropathy in rheumatoid patients

Background:

Rheumatoid arthritis is a multi-system autoimmune disorder predominantly involving multiple small and large joints along with certain extra-articular manifestations. The presence of peripheral neuropathy in patients with rheumatoid arthritis contributes significantly to the functional limitation in patients with rheumatoid arthritis.

Objectives:

To study the prevalence, types, and determinants of peripheral neuropathy in patients with rheumatoid arthritis.

Materials and Methods:

We studied 74 patients with rheumatoid arthritis of at least 2 year duration for the presence of peripheral neuropathy both clinically and electrophysiologically. The data obtained were entered into a database and continuous variables were analyzed using the Student t test and categorical variables were analyzed using the chi-square test.

Results:

Peripheral neuropathy was detected in 39.19% (29 out of 74 patients) patients on electrophysiologic testing and 82.76% (24 out of 29 patients) of the patients were asymptomatic. There was significant association between the presence of peripheral neuropathy and disease duration and rheumatoid factor positivity by the latex agglutination method. Sensory neuropathy was the most common form detected.

Conclusions:

Our study shows that subclinical peripheral neuropathy particularly sensory neuropathy which is not related to disease severity is very common in patients with prolonged disease duration.

Clinical characteristics and prognosis of osteosarcoma in young children: a retrospective series of 15 cases

Background

Osteosarcoma is the most common primary bone malignancy in childhood and adolescence. However, it is very rare in children under 5 years of age. Although studies in young children are limited in number, they all underline the high rate of amputation in this population, with conflicting results being recently reported regarding their prognosis.

Methods

To enhance knowledge on the clinical characteristics and prognosis of osteosarcoma in young children, we reviewed the medical records and histology of all children diagnosed with osteosarcoma before the age of five years and treated in SFCE (Société Française des Cancers et leucémies de l'Enfant) centers between 1980 and 2007.

Results

Fifteen patients from 7 centers were studied. Long bones were involved in 14 cases. Metastases were present at diagnosis in 40% of cases. The histologic type was osteoblastic in 74% of cases. Two patients had a relevant history. One child developed a second malignancy 13 years after osteosarcoma diagnosis.

Thirteen children received preoperative chemotherapy including high-dose methotrexate, but only 36% had a good histologic response. Chemotherapy was well tolerated, apart from a case of severe late convulsive encephalopathy in a one-year-old infant. Limb salvage surgery was performed in six cases, with frequent mechanical and infectious complications and variable functional outcomes.

Complete remission was obtained in 12 children, six of whom relapsed. With a median follow-up of 5 years, six patients were alive in remission, seven died of their disease (45%), in a broad range of 2 months to 8 years after diagnosis, two were lost to follow-up.

Conclusions

Osteosarcoma seems to be more aggressive in children under five years of age, and surgical management remains a challange.

Neurotoxicity of the CNS: diagnosis, treatment and prevention

Treatment-induced CNS toxicity remains a major cause of morbidity in patients with cancer. Real advances in the design of safer radiation procedures have been counterbalanced by a wider use of combined radiotherapy (RT)-chemotherapy regimens, the development of radiosurgery, and the increasing number of long-term survivors. While classic radionecrosis or chemonecrosis have become less common, more subtle changes such as progressive cognitive dysfunction are increasingly reported after RT (radiation-induced leukoencephalopathy) or chemotherapy (administered alone or in combination). The most important and controversial complications of RT, chemotherapy and combined treatments in the CNS are reviewed here, including new diagnostic tools, practical management and prevention that will influence the future management of cancer patients.

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.

The validity of neuropathy and neuropathic pain measures in patients with cancer receiving taxanes and platinums

PURPOSE/OBJECTIVES

To assess the validity of neuropathy and neuropathic pain-measurement approaches.

DESIGN

Cross-sectional measurement study.

SETTING

Two comprehensive cancer centers in the northeastern United States.

SAMPLE

117 patients with cancer in an outpatient setting.

METHODS

Participants were assessed using the five-component Total Neuropathy Score-reduced (TNSr), the TNSr short form (TNSr-SF), individual TNSr items, the Neuropathic Pain Scale for chemotherapy-induced neuropathy (NPS-CIN), and the National Cancer Institute's Common Toxicity Criteria™, version 3.0 (NCI-CTC).

MAIN RESEARCH VARIABLES

Neuropathy and pain measure scores, cumulative and per M2 chemotherapy dosage, comorbid risk factors, drug class, and the number of neurotoxic drugs received.

FINDINGS

TNSr, TNSr-SF, and tendon reflex scores were greater in patients receiving higher cumulative (z range = -2.2 to -3.6; p range = 0.01 to < 0.001) and per M2 (z range = -1.8 to -2.4; p range = 0.04 to < 0.001) chemotherapy doses. Scores from most neuropathy and pain measures were higher in patients with comorbid illnesses (z range = -1.79 to -3.51; p range = 0.03 to < 0.001). Sensory NCI-CTC scores were higher in patients receiving higher cumulative chemotherapy dosage (z = -2.1; p = 0.02). Only the sensory NCI-CTC correlated with other measures (r range = 0.22-0.63; p range = 0.05 to < 0.001).

CONCLUSIONS

Findings support the validity of the TNSr, TNSr-SF, tendon reflex item, NPS-CIN, and NCI-CTC sensory grading scale when measuring taxane and platinum-induced neuropathy. However, additional validity testing is warranted.

IMPLICATIONS FOR NURSING

Comprehensive neuropathy and pain measures mainly used by researchers and neurologists were simplified to more clinically useful tools for use by nurses when monitoring chemotherapy-induced peripheral neuropathy.

Effects of sweet bee venom pharmacopuncture treatment for chemotherapy-induced peripheral neuropathy: a case series

OBJECTIVE

This is a case series reporting safety and degree of response to 1 dose level of sweet bee venom pharmacopuncture (SBVP) or melittin as a symptom-control therapy for chemotherapy-induced peripheral neuropathy (CIPN).

SETTING

All treatments were conducted at the East West Cancer Center (EWCC), Dunsan Oriental Hospital, Daejeon University, Republic of Korea, an institution that uses complementary therapies for cancer patients.

METHODS

Five consecutive patients with CIPN were referred to the EWCC from March 20, 2010, to April 10, 2010. Patients with World Health Organization Chemotherapy-Induced Peripheral Neuropathy (WHO CIPN) grade 2 or more were treated with SBVP for 3 treatment sessions over a 1-week period. Measures of efficacy and safety. Validated Visual Analog System (VAS) pain scale, WHO CIPN grade, and Functional Assessment of Cancer Therapy-General (FACT-G) were compared before and after the 1-week course of treatment. To ensure the safety of SBVP, pretreatment skin response tests were given to patients to avoid any potential anaphylactic adverse effects. All patients were closely examined for any allergenic responses following each treatment session.

RESULTS

One patient discontinued treatment after the first session, and 4 patients completed all treatment sessions. Using each patient as their own comparator, marked improvements of VAS, WHO CIPN grade, and physical section scores of FACT-G were seen in 3 patients. Most important, there were no related adverse side effects found.

CONCLUSION

This safety results of the SBVP therapy merits further investigations in a larger size trial for it to develop into a potential intervention for managing CIPN symptoms. This study will be extended to a dose-response evaluation to further establish safety and response, prior to a randomized trial.

The Relationship between Visuospatial Memory and Coping Strategies in Breast Cancer Survivors

Background:

In the US there are over 2.5 million breast cancer survivors (BCSs), most of whom have required some type of intensive treatment. How individuals cope with the treatment process may relate to why neurocognitive problems arise.

Method:

We explored the impact of treatment for breast cancer (BC) on performance of the Memory Island task, both on working memory and on the general index of cognitive performance in relation to coping strategies of BCSs compared to age-matched controls.

Results:

The evidence obtained suggests a reduced performance in visuospatial memory in BCSs. Those who used emotional coping strategies displayed reduced performance in visuospatial learning and immediate memory. Those women who used problem-focused coping strategies performed better in those tasks measuring psychomotor speed, general intelligence, and delayed visuospatial memory.

Conclusions:

It is concluded that further investigation of the relationship between coping strategies and performance on visuospatial tasks may provide useful information on residual levels of neurocognitive deficits and psychosocial adaptation in BCSs.

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.

Terminal arbor degeneration--a novel lesion produced by the antineoplastic agent paclitaxel

The antineoplastic agent paclitaxel causes a dose-limiting distal, symmetrical, sensory peripheral neuropathy that is often accompanied by a neuropathic pain syndrome. In a low-dose model of paclitaxel-evoked painful peripheral neuropathy in the rat, we have shown that the drug causes degeneration of intraepidermal nerve fibers (IENFs), i.e. the fibers which give rise to the sensory afferent's terminal receptor arbor. However, we did not find any evidence for axonal degeneration in samples taken at the mid-nerve level. Here we aimed to determine whether the absence of degenerating peripheral nerve axons was due to sampling a level that was too proximal. We used electron microscopy to study the distal-most branches of the nerves innervating the hind paw glabrous skin of normal and paclitaxel-treated rats. We confirmed that we sampled at a time when IENF degeneration was prominent. Because degeneration might be easier to detect with higher paclitaxel doses, we examined a four-fold cumulative dose range (8-32 mg/kg). We found no evidence of degeneration in the superficial subepidermal axon bundles (sSAB) that are located just a few microns below the epidermal basal lamina. Specifically, for all three dose groups there was no change in the number of sSAB per millimeter of epidermal border, no change in the number of axons per sSAB and no change in the diameter of sSAB axons. We conclude that paclitaxel produces a novel type of lesion that is restricted to the afferent axon's terminal arbor; we name this lesion 'terminal arbor degeneration'.

Conducting cancer control and survivorship research via cooperative groups: a report from the American Society of Preventive Oncology

As the number of cancer survivors expands, the need for cancer control and survivorship research becomes increasingly important. The National Cancer Institute (NCI) Cooperative Groups may offer a viable platform to perform such research. Observational, preventive, and behavioral research can often be performed within the cooperative group setting, especially if resources needed for evaluation are fairly simple, if protocols are easily implemented within the typical clinical setting, and if interventions are well standardized. Some protocols are better suited to cooperative groups than are others, and there are advantages and disadvantages to conducting survivorship research within the cooperative group setting. Behavioral researchers currently involved in cooperative groups, as well as program staff within the NCI, can serve as sources of information for those wishing to pursue symptom management and survivorship studies within the clinical trial setting. The structure of the cooperative groups is currently changing, but going forward, survivorship is bound to be a topic of interest and one that perhaps may be more easily addressed using the proposed more centralized structure.

Delirium in Palliative Care Patients: Focus on Pharmacotherapy

Patients receiving palliative care often possess multiple risk factors and predisposing conditions for delirium. The impact of delirium on patient care in this population may also be far-reaching: affecting not only quality of remaining life but the dying process experienced by patients, caregivers, and the medical team as well. As palliative care focuses on comfort and symptom management, the approach to assessment and subsequent treatment of delirium in palliative care patients may prove difficult for providers to navigate. This article summarizes the multifactorial nature, numerous predisposing medical risk factors, neuropsychiatric adverse effects of palliative medications, pharmacokinetic changes, and challenges complicating delirium assessment and provides a systematic framework for assessment. The benefits, risks, and patient-specific considerations for treatment selection are also discussed.

Smart drug delivery through DNA/magnetic nanoparticle gates

Mesoporous silica nanoparticles can be modified to perform on-demand stimuli-responsive dosing of therapeutic molecules. The silica network was loaded with iron oxide superparamagnetic nanocrystals, providing the potential to perform targeting and magnetic resonance imaging. Single-stranded DNA was immobilized onto the material surface. The complementary DNA sequence was then attached to magnetic nanoparticles. The present work demonstrates that DNA/magnetic nanoparticle conjugates are able to cap the pores of the magnetic silica particles upon hybridization of both DNA strands. Progressive double-stranded DNA melting as a result of temperature increase gave rise to uncapping and the subsequent release of a mesopore-filled model drug, fluorescein. The reversibility of DNA linkage results in an "on-off" release mechanism. Moreover, the magnetic component of the whole system allows reaching hyperthermic temperatures (42-47 °C) under an alternating magnetic field. This feature leaves open the possibility of a remotely triggered drug delivery. Furthermore, due to its capacity to increase the temperature of the surrounding media, this multifunctional device could play an important role in the development of advanced drug delivery systems for thermochemotherapy against cancer.

HGF/c-Met pathway has a prominent role in mediating antiapoptotic signals through AKT in epithelial ovarian carcinoma

The Met receptor tyrosine kinase and its ligand, hepatocyte growth factor (HGF), are overexpressed and/or activated in a variety of human malignancies. However, its role in epithelial ovarian carcinoma (EOC) has not been clearly elucidated. Therefore, we investigated the role of HGF/c-Met signaling pathway in a large series (156) of Saudi EOC patient samples, a panel of cell lines, and xenografts in a NUDE mouse model. Using immunohistochemistry, c-Met overexpression was found in 27.2% Middle Eastern EOC samples and was associated with an advanced tumor stage (P=0.0187). c-Met overexpression was also associated with antiapoptotic markers X-chromosome-linked inhibitors of apoptosis (XIAP) (P=0.0008) and Bcl-XL (P=0.0493) expression. Treatment of EOC cell lines with PHA665752 causes a dose-dependent inhibition of cell viability and induction of apoptosis. Furthermore, PHA665752 treatment causes dephosphorylation of AKT and downregulation of antiapoptotic proteins XIAP and Bcl-XL. In addition, PHA665752-induced apoptosis occurs through activation of Bax-mediated release of cytochrome c and activation of caspases. Finally, co-treatment of EOC with PHA665752 and cisplatin causes augmented effect on apoptosis of EOC cells and resulted in synergistic inhibition of EOC xenograft tumor growth in NUDE mice. These results indicate that c-Met/HGF pathway may be a potential target for therapeutic intervention for treatment of EOC.