Paclitaxel (Taxol) induces cumulative mild neurotoxicity

Early taxane exposure and neurotoxicity in breast cancer patients

INTRODUCTION

Breast cancer is the most diagnosed tumor and a leading cause of cancer death in women worldwide. Taxanes are the most used chemotherapeutic agents and are strictly connected to neurotoxicity. Taxane-induced neuropathy (TIN) significantly impacts patients' quality of life (QOL). Early identification and management of TIN could improve preventive strategies to preserve patients' QOL during and after breast cancer treatment.

OBJECTIVE

This prospective, observational study aimed to evaluate the taxane-induced neuropathy (TIN) in early breast cancer patients treated with weekly paclitaxel at an earlier stage and identify any correlation between TIN and QOL.

METHODS

Data from stage I-III breast cancer patients treated with taxane-based therapy between 2018 and 2022 were collected at the Medical Oncology Unit of the University Hospital of Cagliari. Peripheral neuropathy was evaluated using the NCI-CTCAE scale (National Cancer Institute, Common Terminology Criteria for Adverse Events) at every drug administration. In contrast, QOL was assessed using EORTC QLC-CIPN20 and FACT-Taxane questionnaire at baseline (T0), after 4 weeks (T1) and 12 (T2) weeks of treatment. Statistical analysis was performed to evaluate the correlation between neurotoxicity and QOL.

RESULTS

Neurotoxicity incidence peaked at the third, fourth, and sixth week of treatment, with patients reporting grade 1 and 2 neurotoxicity. Simultaneously with increasing doses of paclitaxel, significant differences in QOL were observed in early treatment cycles relating to TIN presentation. Patients with higher neurotoxicity grades reported lower QOL scores.

CONCLUSIONS

Despite the absence of effective treatments to prevent paclitaxel-induced neurotoxicity, symptoms are managed through dosage reduction, delay, or treatment interruption. Future research should focus on identifying neuroprotective measures to avoid an irreversible decline in the quality of life for breast cancer survivors.

Chemotherapy-induced peripheral neurotoxicity: single-centre prospective study

OBJECTIVE

Chemotherapy-induced peripheral neurotoxicity (CIPN) ranges from simple paresthesia to paralysis, which may be transient or irreversible. The aim of our study was to detect CINP in our patients undergoing chemotherapy and to study the cumulative neurotoxic doses for the different drugs.

METHODS

This is a cross-sectional prospective study carried out in the medical oncology department of the Habib Bourguiba University Hospital in Sfax. A survey was conducted to detect and explore possible chemo-induced peripheral neuropathy in patients undergoing known potentially neurotoxic anti-cancer treatments.

RESULTS

Seventy-three patients were included in the study. The average age was 51.8 years (13-80 years). The prevalence of CIPN was 52.1%. CIPN was classified as grade I in 24 (63.2%) cases and grade II in 14 (36.8%) cases. No grade III or IV peripheral neuropathy was detected in our patients. Paclitaxel was the drug with the highest incidence of CIPN (76.9%). The chemotherapy (CT) protocols most prone to chemotherapy-induced peripheral neurotoxicity (CIPN) were based on taxanes (47.3%) and oxaliplatin (59%). Paclitaxel was the drug most likely to cause CIPN (76.9%) (p=0.031). Paclitaxel single dose per cycle of 175 mg/m2 (66.67%) was more associated with the occurrence of CIPN than 80 mg/m2 (40%), but without significant difference (p=0.437). The average cumulative dose was estimated at 315 mg/m2 for docetaxel, 474 mg/m2 for oxaliplatin and 579 mg/m2 for paclitaxel (p=0.16).

CONCLUSION

The prevalence of NPCI was 51.1% in our series. Oxaliplatin and taxanes were the main contributors to this complication with cumulative dose over than 300 mg/m2.

Towards a mechanistic understanding of axon transport and endocytic changes underlying paclitaxel-induced peripheral neuropathy

Paclitaxel is a common chemotherapeutic agent widely used to treat solid cancer. However, it frequently causes peripheral sensory neuropathy, resulting in sensory abnormalities and pain in patients receiving treatment for cancer. As one of the most widely used chemotherapeutics, many preclinical studies on paclitaxel-induced peripheral neuropathy (PIPN) have been performed. Yet, there remain no effective options for treatment or prevention. Due to paclitaxel's ability to bind to and stabilize microtubules, a change in microtubule dynamics and subsequent disruptions in axonal transport has been predicted as a major underlying cause of paclitaxel-induced toxicity. However, the systemic understanding of PIPN mechanisms is largely incomplete, and various phenotypes have not been directly attributed to microtubule-related effects. This review aims to provide an overview of the literature involving paclitaxel-induced alteration in microtubule dynamics, axonal transport, and endocytic changes. It also aims to provide insights into how the microtubule-mediated hypothesis may relate to various phenotypes reported in PIPN studies.

Arsenic trioxide dose capping to decrease toxicity in the treatment of acute promyelocytic leukemia

Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) combination therapy yields high complete remission and disease-free survival rates in acute promyelocytic leukemia (APL). ATO is dosed on actual body weight and high ATO doses in overweight patients may contribute to increased toxicity. We performed a retrospective, two-center study comparing toxicities in patients who received the Lo-Coco et al ATRA/ATO regimen with capped ATO, ≤10 mg/dose, and non-capped ATO, >10 mg/dose. A total of 44 patients were included; 15 received doses ≤10 mg and 29 received >10 mg. During induction, there was no difference in the incidence of grade ≥3 hepatotoxicity, grade ≥3 QTc prolongation, neurotoxicity, and cardiac toxicity between groups. In consolidation, patients receiving >10 mg/dose experienced a greater incidence of neurotoxicity (66.7% vs 22.2%; p = 0.046). Capping doses saved $24634.37/patient and reduced waste of partially-used vials. At a median follow-up of 27 months, no disease relapses occurred in either group. This represents an opportunity to improve the safety profile of this highly effective regimen.

Vibration Perception Threshold and Heart Rate Variability as methods to assess chemotherapy-induced neuropathy in women with breast cancer - a pilot study

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a recognized adverse effect of standard (neo)adjuvant chemotherapy in breast cancer (BC) treatment. However, there is no consensus on a validated method for assessing CIPN. Heart rate variability (HRV) and vibration perception threshold (VPT) could be used as objective measures to describe CIPN. The aim of this pilot study was to investigate whether subjectively reported CIPN was associated with altered HRV and VPT in BC patients.

METHODS

We performed a cross-sectional pilot study evaluating 30 BCE patients previously treated with chemotherapy, 26 BCE patients who did not receive chemotherapy, and 22 controls without breast cancer. Self-reported CIPN was registered for the BC patients. All participants were subjected to multi-frequency vibration analyses to determine VPT along with short ECG measurements to determine HRV measures.

RESULTS

Self-reported CIPN was registered in 14 (46.6%) BC patients treated with chemotherapy. The VPT at 64 Hz (P = 0.022) and mean HR (P = 0.022) were significantly higher and the HRV measures SDNN (P = 0.023), RMSSD (P = 0.007), LF (P = 0.050) and HF (P = 0.045) were significantly lower in BC patients reporting CIPN compared to controls when adjusted for age. VPT at 64 Hz and 125 Hz were significantly higher in BC patients not reporting CIPN compared to controls when adjusted for age.

CONCLUSION

We found elevated VPT and mean HR along with decreased HRV parameters in 14 BCE patients reporting CIPN. These findings support the need for further investigation into whether HRV and vibration analysis could contribute to an objective assessment of CIPN.

Heart rate variability and vibration perception threshold to assess chemotherapy-induced neuropathy in women with breast cancer - a systematic review

BACKGROUND

It is well known that breast cancer (BC) patients often suffer from chemotherapy-induced peripheral neuropathy (CIPN). However, it is not always recognized that they have higher risk of falling, dizziness and other signs of dysfunctional autonomous nervous system. We performed a systematic review of the literature on vibration perception threshold (VPT) and heart rate variability (HRV) as methods to objectively assess (CIPN) in BC-patients. Could VPT and HRV describe coexisting sensory and autonomic nerve damage?

MATERIALS AND METHODS

PubMed was searched in September 2019. The included studies had to address HRV and/or VPT in BC-patients who received chemotherapy.

RESULTS

Seven studies assessed VPT and six studies assessed HRV in BC-patients. Studies showed lowered perception of vibrations after chemotherapy reflected in higher VPT and no changes in HRV after taxane-based chemotherapy. No studies evaluated VPT and HRV at the same time.

CONCLUSION

The results were limited by short follow-up, small sample sizes, and different chemotherapy regimens which makes generalizability problematic. A standard assessment method of CIPN is still missing and further research is needed to evaluate if VPT and HRV could contribute to an objective assessment of CIPN. With higher survival rates for BC-patients autonomous and sensory nerve damage will be an increasing task. However, our literature review showed that no one have focused on the combination of autonomous and sensory affection measured by the simple methods VPT and HRV. Therefore, we encourage the development of international guidelines for the objective measure of nerve damage in BC-patients.

Role of Kinematics Assessment and Multimodal Sensorimotor Training for Motion Deficits in Breast Cancer Chemotherapy-Induced Polyneuropathy: A Perspective on Virtual Reality Avatars

Chemotherapy-induced polyneuropathy (CIPN), one of the most severe and incapacitating side effects of chemotherapeutic drugs, is a serious concern in breast cancer therapy leading to dose diminution, delay, or cessation. The reversibility of CIPN is of increasing importance since active chemotherapies prolong survival. Clinical assessment tools show that patients experiencing sensorimotor CIPN symptoms not only do they have to cope with loss in autonomy and life quality, but CIPN has become a key restricting factor in treatment. CIPN incidence poses a clinical challenge and has lacked established and efficient therapeutic options up to now. Complementary, non-opioid therapies are sought for both prevention and management of CIPN. In this perspective, we explore the potential that digital interventions have for sensorimotor CIPN rehabilitation in breast cancer patients. Our primary goal is to emphasize the benefits and impact that Virtual Reality (VR) avatars and Machine Learning have in combination in a digital intervention aiming at (1) assessing the complete kinematics of deficits through learning underlying patient sensorimotor parameters, and (2) parameterize a multimodal VR simulation to drive personalized deficit compensation. We support our perspective by evaluating sensorimotor effects of chemotherapy, the metrics to assess sensorimotor deficits, and relevant clinical studies. We subsequently analyse the neurological substrate of VR sensorimotor rehabilitation, with multisensory integration acting as a key element. Finally, we propose a closed-loop patient-centered design recommendation for CIPN sensorimotor rehabilitation. Our aim is to provoke the scientific community toward the development and use of such digital interventions for more efficient and targeted rehabilitation.

6-Methoxyflavanone abates cisplatin-induced neuropathic pain apropos anti-inflammatory mechanisms: A behavioral and molecular simulation study

Cisplatin is used as a first line therapy in treating cancers. However, its use is often accompanied with the development of peripheral neuropathy. 6-Methoxyflavanone (6-MeOF) is a positive allosteric modulator at GABAA receptors and is known for attenuating diabetes-induced neuropathic pain. Neuropathy was induced in male Sprague-Dawley rats (150-250 g), via intraperitoneal injection of cisplatin (3 mg/kg) once a week for four consecutive weeks. 6-MeOF (25, 50 and 75 mg/kg, i.p) and gabapentin (75 mg/kg, i.p) were administered 30 min before each cisplatin injection. Static and dynamic allodynia were assessed using von Frey filaments and cotton buds. The anti-inflammatory activity was analyzed with plethysmometer. Body weights were also measured each week. The binding affinity of 6-MeOF with chloride channel, Cyclooxygenase-1 (COX-1) and Cyclooxygenase-2 (COX-2) was studied using docking approach. The in vitro COX-1 and COX-2 inhibitory effect of 6-MeOF was conducted with COX colorimetric assay. Administration of cisplatin for four consecutive weeks induced static (decreased paw withdrawal threshold; PWT) and dynamic allodynia (decreased paw withdrawal latency; PWL). Co-administration of 6-MeOF for four weeks significantly attenuated the cisplatin-induced expression of nocifensive behaviors observed as significant increase in PWT and PWL. Moreover, it also prevented the body weight loss induced by cisplatin administration. In silico studies depicted a good interaction of 6-MeOF with chloride ion channels and COX-1 and COX-2 enzymes. The in vitro study confirmed the inhibitory activity of 6-MeOF for COX-1 and COX-2. 6-MeOF may be effective in attenuating cisplatin-induced allodynia, probably through interaction with GABAergic receptors and reducing inflammation.

Role of Germline Genetics in Identifying Survivors at Risk for Adverse Effects of Cancer Treatment

The growing population of cancer survivors often faces adverse effects of treatment, which have a substantial impact on morbidity and mortality. Although certain adverse effects are thought to have a significant heritable component, much work remains to be done to understand the role of germline genetic factors in the development of treatment-related toxicities. In this article, we review current understanding of genetic susceptibility to a range of adverse outcomes among cancer survivors (e.g., fibrosis, urinary and rectal toxicities, ototoxicity, chemotherapy-induced peripheral neuropathy, subsequent malignancies). Most previous research has been narrowly focused, investigating variation in candidate genes and pathways such as drug metabolism, DNA damage and repair, and inflammation. Few of the findings from these earlier candidate gene studies have been replicated in independent populations. Advances in understanding of the genome, improvements in technology, and reduction in laboratory costs have led to recent genome-wide studies, which agnostically interrogate common and/or rare variants across the entire genome. Larger cohorts of patients with homogeneous treatment exposures and systematic ascertainment of well-defined outcomes as well as replication in independent study populations are essential aspects of the study design and are increasingly leading to the discovery of variants associated with each of the adverse outcomes considered in this review. In the long-term, validated germline genetic associations hold tremendous promise for more precisely identifying patients at highest risk for developing adverse treatment effects, with implications for frontline therapy decision-making, personalization of long-term follow-up guidelines, and potential identification of targets for prevention or treatment of the toxicity.

Non-convulsive seizure related to Cremophor EL™-free, polymeric micelle formulation of paclitaxel: a case report

Paclitaxel is a chemotherapeutic agent that is effective against ovarian, breast, lung, and other cancers. Although peripheral neurotoxicity is among the most common side effects of paclitaxel treatment, central neurotoxicity is rarely reported. When centrally mediated side effects are observed, they are attributed to Cremophor EL™ (CrEL), a surfactant-containing vehicle used for paclitaxel administration. In the present report, we discuss the case of a 72-year-old woman with ovarian carcinoma who experienced a non-convulsive seizure following administration of a CrEL-free, polymeric micelle formulation of paclitaxel. One week after her fourth round of chemotherapy, she experienced a transient episode of aphasia for 45 minutes. Electroencephalography demonstrated epileptiform discharges. To our knowledge, this is the first reported case of seizure associated with a CrEL-free formulation of paclitaxel. Although rare, patients and clinicians should remain aware of the risk of non-convulsive seizure following infusion of this paclitaxel formulation.

Chemotherapy-Associated Peripheral Neuropathy in Patients With Early-Stage Breast Cancer: A Systematic Review

Breast cancer is the most common cancer among women worldwide, and survival rates are increasing. Chemotherapy-associated peripheral neuropathy (PN) is clinically important because of effects on quality of life (QOL) and potential effects on dose limitations. This adverse drug reaction is associated with certain classes of chemotherapy and commonly presents as peripheral sensory neuropathy whose natural course is largely unknown. The literature was reviewed to determine the frequency and characteristics of PN associated with adjuvant chemotherapy in early-stage breast cancer (ESBC) to explore the potential impact on long-term (one or more years after diagnosis) health outcomes and QOL. MEDLINE, PubMed, Embase, and the Cochrane Library were searched for relevant English-language randomized controlled trials, systematic reviews, meta-analyses, and case-control and cohort studies published between January 1990 and July 1996. Included studies were limited to current adjuvant regimens (eg, anthracyclines, taxanes, cyclophosphamide, platinum compounds). Two investigators independently reviewed abstracts, full-text articles, and extracted data from fair- and good-quality studies. Discrepancies in quality assessment and data extraction were resolved by consensus. We identified 364 articles; 60 were eligible for full-text review. Only five reports of four studies provided data beyond one year post-treatment initiation. Studies used different measures to assess PN. Neuropathic symptoms persisted in 11.0% to more than 80% of participants at one to three years following treatment. There is a paucity of data describing persistent PN in ESBC patients. Consistent use of validated measures and well-conducted randomized clinical trials or observational studies are needed to evaluate the incidence, persistence, and QOL associated with the long-term effects of PN.

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.

Long-Term Effects, Pathophysiological Mechanisms, and Risk Factors of Chemotherapy-Induced Peripheral Neuropathies: A Comprehensive Literature Review

Neurotoxic anticancer drugs, such as platinum-based anticancer drugs, taxanes, vinca alkaloids, and proteasome/angiogenesis inhibitors are responsible for chemotherapy-induced peripheral neuropathy (CIPN). The health consequences of CIPN remain worrying as it is associated with several comorbidities and affects a specific population of patients already impacted by cancer, a strong driver for declines in older adults. The purpose of this review is to present a comprehensive overview of the long-term effects of CIPN in cancer patients and survivors. Pathophysiological mechanisms and risk factors are also presented. Neurotoxic mechanisms leading to CIPNs are not yet fully understood but involve neuronopathy and/or axonopathy, mainly associated with DNA damage, oxidative stress, mitochondria toxicity, and ion channel remodeling in the neurons of the peripheral nervous system. Classical symptoms of CIPNs are peripheral neuropathy with a “stocking and glove” distribution characterized by sensory loss, paresthesia, dysesthesia and numbness, sometimes associated with neuropathic pain in the most serious cases. Several risk factors can promote CIPN as a function of the anticancer drug considered, such as cumulative dose, treatment duration, history of neuropathy, combination of therapies and genetic polymorphisms. CIPNs are frequent in cancer patients with an overall incidence of approximately 38% (possibly up to 90% of patients treated with oxaliplatin). Finally, the long-term reversibility of these CIPNs remain questionable, notably in the case of platinum-based anticancer drugs and taxanes, for which CIPN may last several years after the end of anticancer chemotherapies. These long-term effects are associated with comorbidities such as depression, insomnia, falls and decreases of health-related quality of life in cancer patients and survivors. However, it is noteworthy that these long-term effects remain poorly studied, and only limited data are available such as in the case of bortezomib and thalidomide-induced peripheral neuropathy.

Pharmacogenetic Discovery in CALGB (Alliance) 90401 and Mechanistic Validation of a VAC14 Polymorphism that Increases Risk of Docetaxel-Induced Neuropathy

PURPOSE

Discovery of SNPs that predict a patient's risk of docetaxel-induced neuropathy would enable treatment individualization to maximize efficacy and avoid unnecessary toxicity. The objectives of this analysis were to discover SNPs associated with docetaxel-induced neuropathy and mechanistically validate these associations in preclinical models of drug-induced neuropathy.

EXPERIMENTAL DESIGN

A genome-wide association study was conducted in metastatic castrate-resistant prostate cancer patients treated with docetaxel, prednisone and randomized to bevacizumab or placebo on CALGB 90401. SNPs were genotyped on the Illumina HumanHap610-Quad platform followed by rigorous quality control. The inference was conducted on the cumulative dose at occurrence of grade 3+ sensory neuropathy using a cause-specific hazard model that accounted for early treatment discontinuation. Genes with SNPs significantly associated with neuropathy were knocked down in cellular and mouse models of drug-induced neuropathy.

RESULTS

A total of 498,081 SNPs were analyzed in 623 Caucasian patients, 50 (8%) of whom experienced grade 3+ neuropathy. The 1,000 SNPs most associated with neuropathy clustered in relevant pathways including neuropathic pain and axonal guidance. An SNP in VAC14 (rs875858) surpassed genome-wide significance (P = 2.12 × 10^-8, adjusted P = 5.88 × 10^-7). siRNA knockdown of VAC14 in stem cell-derived peripheral neuronal cells increased docetaxel sensitivity as measured by decreased neurite processes (P = 0.0015) and branches (P < 0.0001). Prior to docetaxel treatment, VAC14 heterozygous mice had greater nociceptive sensitivity than wild-type litter mate controls (P = 0.001).

CONCLUSIONS

VAC14 should be prioritized for further validation of its potential role as a predictor of docetaxel-induced neuropathy and biomarker for treatment individualization. Clin Cancer Res; 22(19); 4890-900. ©2016 AACR.

Genetic heterogeneity beyond CYP2C8*3 does not explain differential sensitivity to paclitaxel-induced neuropathy

The development of paclitaxel-induced peripheral neuropathy (PIPN) is influenced by drug exposure and patient genetics. The purpose of this analysis was to expand on a previous reported association of CYP2C8*3 and PIPN risk by investigating additional polymorphisms in CYP2C8 and in hundreds of other genes potentially relevant to paclitaxel pharmacokinetics. Clinical data was collected prospectively in an observational registry of newly diagnosed breast cancer patients. Patients treated with paclitaxel-containing regimens were genotyped using the Affymetrix DMET™ Plus chip. Patients who carried the CYP2C8*2, *3, or *4 variant were collapsed into a low-metabolizer CYP2C8 phenotype for association with PIPN. Separately, all SNPs that surpassed quality control were assessed individually and as a composite of genetic ancestry for associations with PIPN. 412 paclitaxel-treated patients and 564 genetic markers were included in the analysis. The risk of PIPN was significantly greater in the CYP2C8 low-metabolizer group (HR = 1.722, p = 0.018); however, the influences of the *2 and *4 SNPs were not independently significant (*2: p = 0.847, *4: p = 0.408). One intronic SNP in ABCG1 (rs492338) surpassed the exploratory significance threshold for an association with PIPN in the Caucasian cohort (p = 0.0008) but not in the non-Caucasian replication group (p = 0.54). Substantial genetic variability was observed within self-reported racial groups but this genetic variability was not associated with risk of grade 2+ PIPN. The pharmacogenetic heterogeneity within a cohort of breast cancer patients is dramatic, though we did not find evidence that this heterogeneity directly influences the risk of PIPN beyond the contribution of CYP2C8*3.

Can medical herbs stimulate regeneration or neuroprotection and treat neuropathic pain in chemotherapy-induced peripheral neuropathy?

Chemotherapy-induced neuropathy (CIPN) has a relevant impact on the quality of life of cancer patients. There are no curative conventional treatments, so further options have to be investigated. We conducted a systematic review in English and Chinese language databases to illuminate the role of medical herbs. 26 relevant studies on 5 single herbs, one extract, one receptor-agonist, and 8 combinations of herbs were identified focusing on the single herbs Acorus calamus rhizoma, Cannabis sativa fructus, Chamomilla matricaria, Ginkgo biloba, Salvia officinalis, Sweet bee venom, Fritillaria cirrhosae bulbus, and the herbal combinations Bu Yang Huan Wu, modified Bu Yang Huan Wu plus Liuwei Di Huang, modified Chai Hu Long Gu Mu Li Wan, Geranii herba plus Aconiti lateralis praeparata radix , Niu Che Sen Qi Wan (Goshajinkigan), Gui Zhi Jia Shu Fu Tang (Keishikajutsubuto), Huang Qi Wu Wu Tang (Ogikeishigomotsuto), and Shao Yao Gan Cao Tang (Shakuyakukanzoto). The knowledge of mechanism of action is still limited, the quality of clinical trials needs further improvement, and studies have not yielded enough evidence to establish a standard practice, but a lot of promising substances have been identified. While CIPN has multiple mechanisms of neuronal degeneration, a combination of herbs or substances might deal with multiple targets for the aim of neuroprotection or neuroregeneration in CIPN.

CYP2C8*3 predicts benefit/risk profile in breast cancer patients receiving neoadjuvant paclitaxel

Paclitaxel is one of the most frequently used chemotherapeutic agents for the treatment of breast cancer patients. Using a candidate gene approach, we hypothesized that polymorphisms in genes relevant to the metabolism and transport of paclitaxel are associated with treatment efficacy and toxicity. Patient and tumor characteristics and treatment outcomes were collected prospectively for breast cancer patients treated with paclitaxel-containing regimens in the neoadjuvant setting. Treatment response was measured before and after each phase of treatment by clinical tumor measurement and categorized according to RECIST criteria, while toxicity data were collected from physician notes. The primary endpoint was achievement of clinical complete response (cCR) and secondary endpoints included clinical response rate (complete response+partial response) and grade 3+ peripheral neuropathy. The genotypes and haplotypes assessed were CYP1B1*3, CYP2C8*3, CYP3A4*1B/CYP3A5*3C, and ABCB1*2. A total of 111 patients were included in this study. Overall, cCR was 30.1% to the paclitaxel component. CYP2C8*3 carriers (23/111, 20.7%) had higher rates of cCR (55% vs. 23%; OR=3.92 [95% CI: 1.46-10.48], corrected p=0.046). In the secondary toxicity analysis, we observed a trend toward greater risk of severe neuropathy (22% vs. 8%; OR=3.13 [95% CI: 0.89-11.01], uncorrected p=0.075) in subjects carrying the CYP2C8*3 variant. Other polymorphisms interrogated were not significantly associated with response or toxicity. Patients carrying CYP2C8*3 are more likely to achieve clinical complete response from neoadjuvant paclitaxel treatment, but may also be at increased risk of experiencing severe peripheral neurotoxicity.

O uso de stents farmacológicos no tratamento da estenose das artérias vertebrais

OBJETIVO: Relatar a viabilidade e segurança da angioplastia transluminal percutânea com stents recobertos com paclitaxel para tratamento de estenose de artéria vertebral em 14 pacientes, após seguimento de dois anos. MATERIAIS E MÉTODOS: Catorze pacientes com idade média de 67,2 anos foram submetidos a tratamento endovascular mediante angioplastia percutânea e implante de stent farmacológico. O objetivo primário deste trabalho foi assegurar a segurança do procedimento. O desfecho secundário foi a eficácia clínica, definida como sintomas isquêmicos recorrentes e taxas de reestenose. RESULTADOS: O grau de estenose variou de 50% a 99% (média de 73,3% ± 10,9). A taxa de sucesso técnico da angioplastia foi de 100%. Não houve complicações diretamente relacionadas ao procedimento. Aos 24 meses de seguimento, nenhum paciente apresentou recorrência dos sintomas. A taxa de reestenose intra-stent foi de 7,1%, embora tenha sido assintomática na totalidade dos casos. CONCLUSÃO: Este estudo sugere que a angioplastia da artéria vertebral com o uso de stents recobertos com paclitaxel é uma técnica viável e promissora em termos de segurança e eficácia na prevenção da isquemia recorrente e reestenose.

The effects of opioid receptor antagonists on electroacupuncture-produced anti-allodynia/hyperalgesia in rats with paclitaxel-evoked peripheral neuropathy

Research supports the effectiveness of acupuncture for conditions such as chronic low back and knee pain. In a five-patient pilot study the modality also improved the symptoms of chemotherapy-induced neuropathic pain. Using an established rat model of paclitaxel-induced peripheral neuropathy, we evaluated the effect of electroacupuncture (EA) on paclitaxel-induced hyperalgesia and allodynia that has not been studied in an animal model. We hypothesize that EA would relieve the paclitaxel-induced mechanical allodynia and hyperalgesia, which was assessed 30 min after EA using von Frey filaments. Beginning on day 13, the response frequency to von Frey filaments (4-15 g) was significantly increased in paclitaxel-injected rats compared to those injected with vehicle. EA at 10 Hz significantly (P<0.05) decreased response frequency at 4-15 g compared to sham EA; EA at 100 Hz only decreased response frequency at 15 g stimulation. Compared to sham EA plus vehicle, EA at 10 Hz plus either a μ, δ, or κ opioid receptor antagonist did not significantly decrease mechanical response frequency, indicating that all three antagonists blocked EA inhibition of allodynia and hyperalgesia. Since we previously demonstrated that μ and δ but not κ opioid receptors affect EA anti-hyperalgesia in an inflammatory pain model, these data show that EA inhibits pain through different opioid receptors under varying conditions. Our data indicate that EA at 10 Hz inhibits mechanical allodynia/hyperalgesia more potently than does EA at 100 Hz. Thus, EA significantly inhibits paclitaxel-induced allodynia/hyperalgesia through spinal opioid receptors, and EA may be a useful complementary treatment for neuropathic pain patients.

BNP7787-mediated modulation of paclitaxel- and cisplatin-induced aberrant microtubule protein polymerization in vitro

Taxane and platinum drugs are important agents in the treatment of cancer and have shown activity against a variety of tumors, including ovarian, breast, and lung cancer, either as single agents or in combination with other chemotherapy drugs. However, a serious and prevalent side effect of taxane (docetaxel and all formulations/derivatives of paclitaxel) and platinum (cisplatin, carboplatin, and oxaliplatin) agents is dose-limiting chemotherapy-induced peripheral neuropathy (CIPN). CIPN can result in treatment delays, dose modifications, and, in severe cases, discontinuation of chemotherapy. Consequently, effective treatments for CIPN are needed. Dimesna (BNP7787; Tavocept; disodium 2,2'-dithio-bis-ethanesulfonate) is an investigational drug that is undergoing international clinical development as a treatment that is coadministered with first-line taxane and platinum combination chemotherapy in patients with inoperable advanced primary adenocarcinoma of the lung. BNP7787 is currently being developed with the objective of increasing the survival of cancer patients receiving taxane- and/or cisplatin-based chemotherapy. Additional data indicate that BNP7787 may also protect against common and serious chemotherapy-induced toxicities, including chemotherapy-induced anemia, nausea, emesis, nephrotoxicity, and neuropathy, without interfering with antitumor activity of the chemotherapeutic agent(s). Studies herein show that BNP7787 prevents aberrant microtubule protein (MTP) polymerization that is caused by exposure of MTP to paclitaxel or cisplatin. BNP7787 modulates paclitaxel-induced hyperpolymerization of MTP in a dose-dependent manner, and mesna, an in vivo metabolite of BNP7787, protects against time-dependent cisplatin-induced inactivation of MTP. We propose that interactions between BNP7787 and MTP may play a role in BNP7787-mediated protection against CIPN.

Paclitaxel: a review of adverse toxicities and novel delivery strategies

Better known as Taxol (Bristol-Myers Squibb), paclitaxel is the first member of the taxane family to be used in cancer chemotherapy. The taxanes exert their cytotoxic effect by arresting mitosis through microtubule stabilization, resulting in cellular apoptosis. The use of paclitaxel as a chemotherapeutic agent has become a broadly accepted option in the treatment of patients with ovarian, breast and non-small cell lung cancers, malignant brain tumors, and a variety of other solid tumors. However, significant toxicities, such as myelosuppression and peripheral neuropathy, limit the effectiveness of paclitaxel-based treatment regimens. This review addresses the toxicities associated with paclitaxel treatment and describes existing and future strategies of paclitaxel administration directed at limiting these toxicities.

Quantitative and Clinical Description of Postural Instability in Women With Breast Cancer Treated With Taxane Chemotherapy

OBJECTIVE

To describe the postural control of women who received taxane chemotherapy for treatment of breast cancer using quantitative and clinically feasible measures.

DESIGN

Prospective descriptive study.

SETTING

University-based comprehensive cancer center.

PARTICIPANTS

Twenty women who completed taxane treatment for breast cancer and 20 healthy controls participated in this study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Two quantitative measures of postural control were used, Sensory Organization Test (SOT) and center of pressure (COP) velocities. Two clinically feasible measures of postural control were used, the Fullerton Advanced Balance Scale (FABS) and Timed Up & Go (TUG) test.

RESULTS

Compared with healthy controls, women with breast cancer had poorer postural control on all of the outcome measures. FABS and TUG scores correlated moderately with SOT and COP scores.

CONCLUSIONS

After taxane chemotherapy, women with breast cancer show significantly increased postural instability compared with matched controls. Clinically feasible measures of postural control correlated with quantitative tests. These results suggest that these clinical measures may be useful to screen patients to determine who may benefit from rehabilitation.

Diagnosis, management, and evaluation of chemotherapy-induced peripheral neuropathy

Peripheral neuropathy induced by cancer chemotherapy represents a large unmet need for patients due to the absence of treatment that can prevent or mitigate this common clinical problem. Chemotherapy-induced peripheral neuropathy (CIPN) diagnosis and management is further compounded by the lack of reliable and standardized means to diagnose and monitor patients who are at risk for, or who are symptomatic from, this complication of treatment. The pathogenesis and pathophysiology of CIPN are not fully elucidated, but there is increasing evidence of damage or interference with tubulin function. The diagnosis of CIPN may present a diagnostic dilemma due to the large number of potential toxic etiologies and conditions, which may mimic some of the clinical features; the diagnosis must be approached with care in such patients. The incidence and severity of CIPN is commonly under-reported by physicians as compared with patients. The development of new and reliable methods for the assessment of CIPN as well as safe and effective treatments to prevent this complication of treatment would represent important medical advancements for cancer patients.

Peripheral neuropathy induced by paclitaxel: recent insights and future perspectives

Paclitaxel is an antineoplastic agent derived from the bark of the western yew, Taxus brevifolia, with a broad spectrum of activity. Because paclitaxel promotes microtubule assembly, neurotoxicity is one of its side effects. Clinical use of paclitaxel has led to peripheral neuropathy and this has been demonstrated to be dependent upon the dose administered, the duration of the infusion, and the schedule of administration. Vehicles in the drug formulation, for example Cremophor in Taxol, have been investigated for their potential to induce peripheral neuropathy. A variety of neuroprotective agents have been tested in animal and clinical studies to prevent paclitaxel neurotoxicity. Recently, novel paclitaxel formulations have been developed to minimize toxicities. This review focuses on recent advances in the etiology of paclitaxel-mediated peripheral neurotoxicity, and discusses current and ongoing strategies for amelioration of this side effect.

Studies of peripheral sensory nerves in paclitaxel-induced painful peripheral neuropathy: evidence for mitochondrial dysfunction

Paclitaxel chemotherapy frequently induces neuropathic pain during and often persisting after therapy. The mechanisms responsible for this pain are unknown. Using a rat model of paclitaxel-induced painful peripheral neuropathy, we have performed studies to search for peripheral nerve pathology. Paclitaxel-induced mechano-allodynia and mechano-hyperalgesia were evident after a short delay, peaked at day 27 and finally resolved on day 155. Paclitaxel- and vehicle-treated rats were perfused on days 7, 27 and 160. Portions of saphenous nerves were processed for electron microscopy. There was no evidence of paclitaxel-induced degeneration or regeneration as myelin structure was normal and the number/density of myelinated axons and C-fibres was unaltered by paclitaxel treatment at any time point. In addition, the prevalence of ATF3-positive dorsal root ganglia cells was normal in paclitaxel-treated animals. With one exception, at day 160 in myelinated axons, total microtubule densities were also unaffected by paclitaxel both in C-fibres and myelinated axons. C-fibres were significantly swollen following paclitaxel at days 7 and 27 compared to vehicle. The most striking finding was significant increases in the prevalence of atypical (swollen and vacuolated) mitochondria in both C-fibres (1.6- to 2.3-fold) and myelinated axons (2.4- to 2.6-fold) of paclitaxel-treated nerves at days 7 and 27. Comparable to the pain behaviour, these mitochondrial changes had resolved by day 160. Our data do not support a causal role for axonal degeneration or dysfunction of axonal microtubules in paclitaxel-induced pain. Instead, our data suggest that a paclitaxel-induced abnormality in axonal mitochondria of sensory nerves contributes to paclitaxel-induced pain.

Mild cognitive impairment after adjuvant chemotherapy in breast cancer patients--evaluation of appropriate research design and methodology to measure symptoms

The development of new chemotherapeutic agents and regimens has contributed to reduced risk of cancer recurrence and prolonged patient survival. However, mild cognitive impairment (MCI), also known as ''chemofog'' or ''chemobrain'' following adjuvant chemotherapy for breast cancer has been reported since the late 1980s. Unfortunately, little is known about it's mechanism, type, severity, and episode length. This article reviewed related studies on the subject, and found that chemotherapy-induced MCI appears to occur in 10-40% of patients, and memory loss and lack of concentration are the most frequent symptoms. The symptoms are apparently transient, but take at least several years to disappear. Reviewed studies show a lack of clear understanding of what causes MCI directly. There is also a lack of consistency in symptom measurement. We point to the need to conduct well-designed studies which begin with a proper hypothesis. Future research needs to be randomized and longitudinal with a base measurement point before the chemotherapy cycle starts. Future studies must adopt an effective and sensitive method to measure MCI. The latest imaging technique, positron emission tomography (PET) may be a powerful tool. Also, all confounding factors, such as age, education, intelligence quotient (IQ), fatigue and depression, hormonal therapy and other treatments should be controlled within the study design. It is hoped that the results of such future studies will allow medical professionals to contemplate effective prevention, treatment and rehabilitation for MCI.

Peripheral neuropathy: A persisting challenge in paclitaxel-based regimes

Cumulative peripheral neuropathy (PNP) still remains a limitation to optimal treatment with paclitaxel (PAC), especially in more dose-dense schedules. This primary sensory PNP may affect the majority of patients after administration of certain cumulative dosages of PAC, while the exact mechanisms of PAC-induced PNP are not known. While a number of preclinical models revealed its vehicle Cremophor EL (CrEL) to be mainly responsible for ganglionopathy, axonopathy and demyelination, clinical data also supports a strong and independent effect of PAC itself, which is most likely based on disturbances in the microtubules in perikaryons, axons and glia cells. Indeed, clinical trials of CrEL-free formulations of PAC still report grade III neurotoxicity as dose-limiting. As treatment options of PAC-induced PNP are rare the use of specific scoring systems for screening purposes is strongly encouraged. In this report we review and discuss the pathogenesis, incidence, risk factors, diagnosis, pharmacodynamics and treatment options for PAC-induced PNP.

Case Report: Painful Peripheral Neuropathy Following Treatment With Docetaxel for Breast Cancer

Peripheral neuropathy is a common side effect of many chemotherapy agents. As many as 60% of patients receiving taxane therapy report symptoms such as numbness, tingling, burning, pain, and, in severe cases, weakness in a stocking and glove pattern. These symptoms are associated with problems in physical mobility and decreased quality of life, yet few articles in the literature discuss collaborative interdisciplinary assessment and treatment of this population. This article describes the care of a patient with diabetes and docetaxel-induced, painful peripheral neuropathy by a multidisciplinary team of nurses, physicians, and physical therapists. Because nurses are often the first clinicians to recognize symptoms of chemotherapy-induced peripheral neuropathy, they provide the essential coordination of care by appropriate medical and rehabilitative services. This case also raises important questions about the relationship between diabetes mellitus and persistent, painful peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy

PURPOSE/OBJECTIVES

To review the literature documenting the scope, treatment, and prevention of chemotherapy-induced neuropathy.

DATA SOURCES

Published abstracts, primary research literature, and textbook chapters.

DATA SYNTHESIS

Recent improvements in the management of other treatment-related toxicities have led to peripheral neuropathy becoming a dose-limiting toxicity of commonly used chemotherapeutic groups such as platinols, vinca alkaloids, and taxanes.

CONCLUSIONS

The nervous system has not been the focus of education or training for oncology nurses. Therefore, nurses' ability to educate patients regarding this aspect of their condition has been limited.

IMPLICATIONS FOR NURSING

With its significant impact on quality of life, peripheral neuropathy treatment and prevention are important components in the care of patients with cancer.

A randomized, double-blinded, placebo-controlled phase II trial of recombinant human leukemia inhibitory factor (rhuLIF, emfilermin, AM424) to prevent chemotherapy-induced peripheral neuropathy

PURPOSE

To determine whether recombinant human leukemia inhibitory factor (rhuLIF, AM424, emfilermin) can prevent or ameliorate the development of chemotherapy-induced peripheral neuropathy (CIPN) after treatment with carboplatin (AUC 6) and paclitaxel (175 mg/m(2) over 3 hours).

EXPERIMENTAL DESIGN

Randomized double-blind placebo-controlled phase II clinical trial. Eligible patients had solid tumors for which treatment with carboplatin/paclitaxel was appropriate. The primary end point was a standardized composite peripheral nerve electrophysiology (CPNE) score, based on nerve velocities and amplitudes, measured at baseline and after four cycles of chemotherapy. Secondary efficacy end points included CPNE score at last cycle and at exit evaluation, vibration perception threshold, H-reflex latency, symptom scores, and quantitative assessment of neurologic signs. Study drug was given s.c. daily for 7 days starting the day before chemotherapy. Patients were randomized to receive low-dose rhuLIF (2 microg/kg), high-dose rhuLIF (4 microg/kg), or placebo.

RESULTS

Patients (n = 117) were randomized across seven neurology test centers. Thirty-six patients received low dose rhuLIF (2 microg/kg), 39 received high dose rhuLIF (4 microg/kg) and 42 received placebo. rhuLIF was well tolerated with 95% compliance and no adverse effects on quality of life. No differences between groups in CPNE or any of the individual neurologic testing variables were observed between baseline and cycle 4 or by the secondary efficacy variables.

CONCLUSIONS

rhuLIF is not effective in preventing CIPN caused by carboplatin and paclitaxel. CPNE is a reliable and valid tool that was sensitive to the onset and progression of CIPN.

Taxol-induced sensory disturbance is characterized by preferential impairment of myelinated fiber function in cancer patients

Taxol produces neuropathic pain with three distinct zones of involvement in the extremities. Most distally is an area of on-going pain and proximal to this is a zone of sensory disturbance but not overt pain. These two areas were confined in all but one case to the glabrous skin of the hands and/or feet. More proximal is an area not recognized by the patients as involved with pain or sensory disturbance yet wherein quantitative sensory tests nevertheless reveal altered sensibility. Impairment of perception to light touch, normally conveyed by myelinated fibers, was dramatically altered in all three areas, being approximately 50-fold greater than normal in areas of pain and sensory disturbance as well as in areas of skin perceived by the patients as not affected. Impairment of perception to sharpness, normally conveyed by small myelinated fibers, was most pronounced in areas of on-going pain, intermediate in areas of sensory disturbance and near baseline in more proximal skin of chemotherapy patients. In contrast to mechanical sensibility, thermal thresholds for warm and heat pain detection were normal throughout. Finally, chemotherapy patients showed paradoxical burning pain to skin cooling that was most pronounced in proximal areas of skin thought to be unaffected by the patients, intermediate in the border zone of altered sensibility and least pronounced in areas of on-going pain. These data suggest that taxol produces a neuropathy characterized by pronounced impairment of function in A-beta myelinated fibers, intermediate impairment of A-delta myelinated fibers, and a relative sparing of C-fibers.

Ethosuximide reverses paclitaxel- and vincristine-induced painful peripheral neuropathy

Paclitaxel (Taxol) is one of the most effective and frequently used chemotherapeutics for the treatment of solid tumours. However, paclitaxel produces peripheral neurotoxicity with patients reporting sensory abnormalities and neuropathic pain during and often persisting after paclitaxel therapy. The mechanisms underlying this dose-limiting side effect are currently unknown and there are no validated drugs for its prevention or control. Male Sprague-Dawley rats received four intraperitoneal (i.p.) injections on alternate days of 2 mg/kg paclitaxel. Behavioural assessment using von Frey filaments and acetone showed that such paclitaxel treatment induced a pronounced mechanical and cold allodynia/hyperalgesia. Thus these studies aim to test potential analgesics on established paclitaxel-induced pain. Paclitaxel-induced pain appears to be relatively resistant to opioid therapy i.p. 4 mg/kg morphine was ineffective and i.p. 8 mg/kg morphine only elicited up to a 50% reversal of mechanical allodynia/hyperalgesia. Interestingly, a maximally tolerated dose (i.p. 0.2 mg/kg) of the potent NMDA receptor antagonist MK-801 produced no significant reversal of the mechanical allodynia/hyperalgesia suggesting that NMDA receptors have little role in paclitaxel-induced pain. Ethosuximide (i.p. 450 mg/kg) an anti-epileptic and relatively selective T-type calcium channel blocker elicited a near complete reversal of mechanical allodynia/hyperalgesia. Repetitive dosing with ethosuximide (i.p. 100 or 300 mg/kg daily for 3 days) showed a dose-related consistent reversal of mechanical allodynia/hyperalgesia with no evidence of tolerance. Ethosuximide (i.p. 300 mg/kg) also reversed paclitaxel-induced cold allodynia and vincristine-induced mechanical allodynia/hyperalgesia. These data suggest that T-type calcium channels may play a role in chemotherapy-induced neuropathy and moreover identify ethosuximide as a new potential treatment for chemotherapy-induced pain.

Neurotoxicity of taxanes: symptoms and quality of life assessment

Paclitaxel (TXL) and docetaxel (TXT), especially TXL, cause neurotoxicity manifested as polyneuropathy. In clinical practice, detailed knowledge of the symptoms and effect on quality of life (QOL) of neurotoxicity is crucially important both for diagnosis of neuropathy and for management of patients treated with taxanes. In this review, we summarize the symptoms of neurotoxicity caused by taxanes, and highlight the importance of QOL assessment in breast cancer patients treated with taxanes. The most common feature of taxane neurotoxicity is a predominant sensory distal neuropathy, and the incidence and severity of the neuropathic manifestations appear to be related to dose level and cumulative dose. A mixture of paresthesias and dysesthesias is often prominent, and the complaints include burning dysesthesia, numbness, tingling, and shooting pains, typically in a stocking-glove distribution. In contrast to sensory disturbances, motor neuropathy is not well recognized, and is believed to be much less common than sensory neuropathy. Weakness is usually mild, and distal motor neuropathy caused by taxanes rarely affects patients' activities of daily living. The effect of neurotoxicity on QOL is not fully understood, as no study has specifically assessed QOL in terms of neurotoxicity. There is therefore a clear need to collect more detailed data about QOL using well validated, reliable instruments. This will enable us to provide the information that patients require when treatment decisions are being made, and will help in the pursuit of the ameliorative interventions.

Treatment and care of neurotoxicity from taxane anticancer agents

Taxane anticancer agents play a central role in drug therapy for breast cancer today; however, they have a dose-limiting neurotoxicity that is difficult to prevent and treat. To protect against this neurotoxicity it is important to avoid large doses greater than 200 mg/m2, and to adopt 24-hour administration regimens. Care is also needed with regard to the cumulative dose. Glutamine and amitriptyline are two of the very few drugs that have been found to be clinically effective against drug-induced peripheral neuropathy. Drugs are discontinued if neuropathy appears. If administration is to be later restarted, it is recommended that combined use of glutamine or amitriptyline be considered and that patients be given guidance for daily life.

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

Neurotoxic side effects of chemotherapy occur frequently and are often a reason to limit the dose of chemotherapy. Since bone marrow toxicity, as the major limiting factor in most chemotherapeutic regimens, can be overcome with growth factors or bone marrow transplantation, the use of higher doses of chemotherapy is possible, which increases the risk of neurotoxicity. Chemotherapy may cause both peripheral neurotoxicity, consisting mainly of a peripheral neuropathy, and central neurotoxicity, ranging from minor cognitive deficits to encephalopathy with dementia or even coma. In this article we describe the neurological adverse effects of the most commonly used chemotherapeutic agents. The vinca-alkaloids, cisplatin and the taxanes are amongst the most important drugs inducing peripheral neurotoxicity. These drugs are widely used for various malignancies such as ovarian and breast cancer, and haematological cancers. Chemotherapy-induced neuropathy is clearly related to cumulative dose or dose-intensities. Patients who already have neuropathic symptoms due to diabetes mellitus, hereditary neuropathies or earlier treatment with neurotoxic chemotherapy are thought to be more vulnerable for the development of chemotherapy-induced peripheral neuropathy. Methotrexate, cytarabine (cytosine arabinoside) and ifosfamide are primarily known for their central neurotoxic side effects. Central neurotoxicity ranges from acute toxicity such as aseptic meningitis, to delayed toxicities comprising cognitive deficits, hemiparesis, aphasia and progressive dementia. Risk factors are high doses, frequent administration and radiotherapy preceding methotrexate chemotherapy, which appears to be more neurotoxic than methotrexate as single modality. Data on management and neuroprotective agents are discussed. Management mainly consists of cumulative dose-reduction or lower dose-intensities, especially in patients who are at higher risk to develop neurotoxic side effects. None of the neuroprotective agents described in this article can be recommended for standard use in daily practise at this moment, and further studies are needed to confirm some of the beneficial effects described.

A novel intraarterial chemotherapy using paclitaxel in albumin nanoparticles to treat advanced squamous cell carcinoma of the tongue: preliminary findings

OBJECTIVE

The purpose of our study was to evaluate the effectiveness of intraarterial infusion of paclitaxel incorporated into human albumin nanoparticles for use as induction chemotherapy before definitive treatment of advanced squamous cell carcinoma of the tongue.

SUBJECTS AND METHODS

Twenty-three previously untreated patients (age range, 27-75 years) who had carcinoma of the tongue (stage T3-T4, any N) received intraarterial therapy with paclitaxel incorporated into albumin nanoparticles delivered by transfemoral catheterization into the external carotid artery (10 patients), selectively into the lingual artery (12 patients), or into a faciolingual trunk (1 patient). Each patient received two to four infusions, with a 3-week interval between infusions. The dose administered was 230 mg/m(2) in eight patients, 180 mg/m(2) in six patients, and 150 mg/m(2) in nine patients. Sixteen patients underwent surgery. Of these 16 patients, eight subsequently received radiotherapy, and three received a combination of chemotherapy and radiotherapy. Of the remaining seven patients, one received chemotherapy alone, four received radiotherapy alone, one received chemotherapy plus radiotherapy, and one refused any further treatment.

RESULTS

Sixty-seven infusions were performed successfully. Eighteen patients (78%) had a clinical and radiologic objective response (complete, 26%; partial, 52%). Three patients (13%) showed stable disease, and two (9%) showed disease progression. The four patients with complete clinical response who underwent surgery showed microscopic residual carcinoma measuring less than 1 mm in two patients, less than 5 mm in one patient, and less than 1 cm in one patient. The toxicities encountered were hematologic (grade 3) in two patients (8.6%) and neurologic (grade 4) in two patients (reversible paralysis of the facial nerve, 8.6%). Two catheter-related complications occurred: one reversible brachiofacial paralysis and one asymptomatic occlusion of the external carotid artery.

CONCLUSION

Intraarterial infusion of paclitaxel in albumin nanoparticles proved reproducible and effective and deserves further investigation as induction chemotherapy before definitive treatment of advanced tumors of the tongue, with a view to organ preservation.

Role of protein kinase Cepsilon and protein kinase A in a model of paclitaxel-induced painful peripheral neuropathy in the rat

The clinical use of the antineoplastic agent paclitaxel (Taxol) is significantly limited in its effectiveness by a dose-related painful peripheral neuropathy. To evaluate underlying mechanisms, we developed a model of Taxol-induced painful peripheral neuropathy in the rat and determined the involvement of two second messengers that contribute to enhanced nociception in other models of inflammatory and neuropathic pain, protein kinase Cepsilon and protein kinase A. Taxol administered acutely, or chronically over 12 days, produced a decrease in mechanical nociceptive threshold. Acutely, Taxol induced hyperalgesia that was significant within 1 h, maximal after 6 h and resolved completely by 24 h after a single treatment. Chronically, Taxol treatment resulted in a dose (0.1-1 mg/kg/day)-dependent decrease in nociceptive threshold, measured 24 h after administration, maximal within 5 days from the commencement of Taxol administration and resolving by 2 weeks after the last dose of Taxol. Chronic Taxol treatment also increased the number of action potentials evoked by sustained (60-s) threshold and suprathreshold (10-g) stimulation of a sub-population of C-fibers in rats with Taxol-induced hyperalgesia. Mechanical allodynia and thermal hyperalgesia were also present in Taxol-treated rats. Hyperalgesia, produced by both acute and chronic Taxol, was attenuated by intradermal injection of selective second messenger antagonists for protein kinase Cepsilon and protein kinase A. These findings provide insight into the mechanism of Taxol-induced painful peripheral neuropathy that may help control side effects of chemotherapy and improve its clinical efficacy.

A painful peripheral neuropathy in the rat produced by the chemotherapeutic drug, paclitaxel

Paclitaxel, an effective anti-neoplastic agent in the treatment of solid tumors, produces a dose-limiting painful peripheral neuropathy in a clinically significant number of cancer patients. Prior work has demonstrated paclitaxel-induced neurodegeneration and sensory loss in laboratory rodents. We describe here an experimental paclitaxel-induced painful peripheral neuropathy. Adult male rats were given four intraperitoneal injections on alternate days of vehicle or 0.5, 1.0, or 2.0 mg/kg of paclitaxel (Taxol). Behavioral tests for pain using mechanical and thermal stimuli applied to the tail and hind paws, and tests for motor performance, were taken before, during and after dosing for 22-35 days. All three doses of paclitaxel caused heat-hyperalgesia, mechano-allodynia, mechano-hyperalgesia, and cold-allodynia, but had no effect on motor performance. Neuropathic pain began within days and lasted for several weeks. We did not detect any dose-response relationship. Tests at the distal, mid, and proximal tail failed to show evidence of a length-dependent neuropathy. Vehicle control injections had no effect on any measure. No significant systemic toxicities were noted in the paclitaxel-treated animals. Light-microscopic inspection of the sciatic nerve (mid-thigh level), L4-L5 dorsal root ganglia, and dorsal and ventral roots, and the gray and white matter of the L4-L5 spinal cord, showed no structural abnormalities. Electron microscopic examination of the sciatic nerve (mid-thigh level) and the L4-L5 dorsal root ganglia and dorsal horns demonstrated no degeneration of myelinated and unmyelinated axons in the sciatic nerve and roots, but revealed endoneurial edema. This model may be useful in understanding a significant source of pain in cancer patients, and in finding ways to avoid the neurotoxicity that limits paclitaxel therapy.

Paclitaxel and carboplatin in combination with gemcitabine: a phase I-II trial in patients with advanced non-small-cell lung cancer. Gruppo Studio Tumori Polmonari Veneto (GSTPV)

BACKGROUND

The combination of paclitaxel (P) and carboplatin (C) is an effective treatment for advanced NSCLC. Gemcitabine (G) is an active new drug. We planned a phase I study to find the maximum tolerated dose (MTD) of the PCG combination. A phase II study was subsequently conducted to evaluate the activity and toxicity of PCG.

PATIENTS AND METHODS

Forty-five patients entered the study. Twenty-eight had stage IIIA-B disease, 17 stage IV. In the phase I study, with a fixed dose of C at AUC = 6 on day 1, P was escalated using increments of 25 mg/m2 starting from 175 mg/m2 on day 1 and G with increments of 200 mg/m2 starting from 800 mg/m2 on day 1 and 8.

RESULTS

Fourteen patients entered the phase I study. The MTD was reached at P 200 mg/m2, C AUC = 6 and G 1000 mg/m2. Neutropenic fever and grade 3 diarrhea were the dose limiting toxicities. Thirty-one patients were treated in the phase II study with P 175 mg/m2, C AUC = 6 and G 1000 mg/m2. Response rate was 57% (68% in stage III and 47% in stage IV). Myelosuppression was the main toxicity, with grade 3-4 leukopenia occurring in 35% of cases. Grade 3 anemia was observed in 24% of cases and grade 3-4 thrombocytopenia occurred in 34% of patients. Non-hematological toxicity was mild. Median survival and one-year actuarial survival were 20.5 months and 74% for stage III and 11.5 months and 47% for stage IV.

CONCLUSIONS

PCG is a promising regimen for treating advanced NSCLC. A phase III study comparing PCG to paclitaxel plus carboplatin in advanced NSCLC is ongoing. On the other hand, we are planning to introduce the PCG regimen in the treatment of stage II-III patients in the setting of a multimodality treatment.

Peripheral neuropathy due to biweekly paclitaxel, epirubicin and cisplatin in patients with advanced ovarian cancer

We assessed the peripheral neuropathic changes induced by biweekly combination chemotherapy including paclitaxel 100-165 mg/m2 (in a 3-h infusion), epirubicin 75 mg/m2 and cisplatin 50 mg/m2 (TEC) in patients with advanced ovarian cancer. Neurologic evaluation, including a standardized questionnaire, bed-side neurological examination, and quantitative determination of vibratory perception thresholds (VPT) and grip strength took place before therapy, after 3 and 6 cycles, and thereafter whenever possible. During chemotherapy all patients received granulocyte colony-stimulating factor from days 2 to 12. Pretreated patients received amifostine two times, before epirubicin and before cisplatin administration. Neuropathic symptoms developed in 11/13 non-pretreated patients and in 7/9 chemotherapy-pretreated patients. Neuropathic signs developed in all patients. Neuropathic symptoms and signs were predominantly sensory in character. VPT changes developed primarily in the feet. According to National Cancer Institute of Canada Common Toxicity Criteria, grade 3 peripheral neuropathy after 6 cycles developed in 1/6 and 2/4 non-pretreated patients who received TEC containing paclitaxel 150 and 165 mg/m2, respectively. We conclude that peripheral neuropathy is dose-limiting in chemonaïve patients treated with biweekly TEC combination chemotherapy, at paclitaxel dose level 165 mg/m2 in a 3-h intravenous administration.

Phase II study of paclitaxel and epirubicin as first-line treatment in patients with metastatic nonsmall cell lung carcinoma

BACKGROUND

The combination of paclitaxel and epirubicin has shown a favorable interaction in patients with advanced breast carcinoma. Therefore the efficacy and toxicity of this regimen was evaluated in a Phase II study of patients with metastatic nonsmall cell lung carcinoma (NSCLC).

METHODS

Thirty-two chemotherapy-naive patients with AJCC Stage IV NSCLC and an Eastern Cooperative Oncology Group performance status of 0-1 were entered into the study. Patients received epirubicin, 90 mg/m(2), followed by paclitaxel, 175 mg/m(2) by 3-hour infusion, on Day 1. The treatment was repeated every 3 weeks. Granulocyte-colony stimulating factor (G-CSF) was not used routinely.

RESULTS

A total of 116 treatment cycles was delivered. All patients could be assessed for response, toxicity, and survival. There were 16 partial responses and no complete responses, giving rise to an overall response rate of 50% (95% confidence interval, 31. 9-68.1%). The median time to progression in responders was 7 months. The median survival was 8 months, and the 1-year survival rate was 37%. World Health Organization Grade 4 neutropenia occurred in 69% of patients, but could be managed easily with G-CSF, which was used in 35% of cycles. Cumulative peripheral neuropathy was the main nonhematologic toxicity and was observed in 7 of 8 patients who received 6 treatment courses (Grade 2-3 in 3 cases) and in 6 of 11 patients who received 4 cycles (Grade 2 in 2 patients). One patient died shortly after the first course of chemotherapy from a ventricular arrhythmia.

CONCLUSIONS

The combination of paclitaxel and epirubicin was found to be effective and well tolerated in chemotherapy-naive patients with metastatic NSCLC and warrants further evaluation in a multicenter trial of a larger number of patients. Careful cardiac evaluation before treatment is indicated.

Bilateral facial nerve palsy secondary to the administration of high-dose paclitaxel

Bilateral facial nerve palsy is an uncommon occurrence. We describe a case of bilateral facial nerve palsy secondary to a single cycle of high-dose paclitaxel therapy (825 mg/m2), in a woman with breast cancer. Prior to her high-dose therapy, she had a residual grade 2 peripheral neuropathy following treatment with ten cycles of standard-dose paclitaxel (total dose 3200 mg). The features of the peripheral neuropathy due to standard-dose paclitaxel, which can be both motor and sensory, are well described. Cumulative paclitaxel dose is considered a risk factor for development of the neuropathy. Although facial nerve palsy secondary to paclitaxel is not previously reported, other cranial nerve toxicity has been described. Consistent with reports of the reversibility of paclitaxel-induced peripheral neuropathy, the facial nerve palsies in our patient resolved over 23 months. Ongoing studies of high-dose paclitaxel warrant close attention to its cumulative neurotoxic effects, particularly in patients previously treated with neurotoxic chemotherapy.

Physiological characterization of Taxol-induced large-fiber sensory neuropathy in the rat

The cancer chemotherapeutic agent Taxol (paclitaxel) causes a dose-related peripheral neuropathy in humans. We produced a dose-dependent large-fiber sensory neuropathy, without detrimental effects on general health, in mature rats by using two intravenous injections 3 days apart. Tests of other dosing schedules demonstrated the dependence of the severity of the neuropathy and of animal health on both the dose and the frequency of dosing. Pathologically, severe axonal degeneration and hypomyelination were observed in sections of dorsal roots, whereas ventral roots remained intact. Electrophysiologically, H-wave amplitudes in the hindlimb and amplitudes of predominantly sensory compound nerve action potentials in the tail were reduced. These effects persisted for at least 4 months after treatment. Motor amplitudes were not affected, but both motor and sensory conduction velocities decreased. The ability of rats to remain balanced on a narrow beam was impaired, indicating proprioceptive deficits. Muscle strength, measured by hindlimb and forelimb grip strength, and heat nociception, measured by tail-flick and hindlimb withdrawal tests, were not affected by Taxol. This model of Taxol-induced neuropathy in mature rats, with minimal effects on general health, parallels closely the clinical syndrome observed after Taxol treatment in humans.