Clinical management of oxaliplatin-associated neurotoxicity

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (25 August 2010), the Cochrane Central Register of Controlled Trials (Issue 3, 2010 in The Cochrane Library), MEDLINE (January 1966 to August 2010), EMBASE (January 1980 to August 2010), LILACS (January 1982 to August 2010), CINAHL (January 1982 to August 2010) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients.

SELECTION CRITERIA

Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential chemoprotectant (acetylcysteine, amifostine, ACTH, BNP7787, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary).

DATA COLLECTION AND ANALYSIS

We identified 16 randomized trials involving five possible chemoprotective agents in the initial 2006 review. Each study was reviewed by two authors who extracted the data and reached consensus. The 2010 update identified 11 additional randomized trials consisting of nine possible chemoprotective agents, including three treatments (acetylcysteine, calcium and magnesium, and oxcarbazepine) not among those described in the 2006 review. The included trials in the updated review involved eight unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances.

MAIN RESULTS

One of four eligible amifostine trials (541 total participants in all four trials) used quantitative sensory testing and demonstrated a favorable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Of the six eligible glutathione trials (354 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The single eligible trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), calcium and magnesium (33 participants), and oxcarbazepine (32 participants) and the two eligible trials involving vitamin E (57 participants) did not perform quantitative sensory testing. In all, data from 1,537 participants were included.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Balancing the efficacy and toxicity of chemotherapy in colorectal cancer

As the therapeutic options for the treatment of colorectal cancer have expanded over the past 20 years, so has the complexity of decision making. The goals of treatment in the palliative, adjuvant and neoadjuvant settings vary and it is not only the efficacy of drugs that influence treatment decisions. Age, performance status, the presence of significant comorbidities and the different treatment regimens and strategies provide medical oncologists with an array of options to attempt to maximize patients' quality of life and longevity.

Oxaliplatin-induced chronic peripheral neurotoxicity: a prospective analysis in patients with colorectal cancer

Purpose

Oxaliplatin-induced chronic peripheral neurotoxicity (OXCPN) manifests as a loss of sensation and dysesthesia in the distal extremities, which may impair daily activities and increase in incidence with the amount of oxaliplatin delivered. The variation in the reported incidence and severity of OXCPN may be a consequence of differences in the baseline characteristics of patients.

Materials and Methods

This was a prospective study (ClinicalTrials.gov, NCT00977717) in which OXCPN was recorded for all consecutive colon cancer patients treated at Samsung Medical Center (Seoul, Korea) with oxaliplatin-based combination chemotherapy. The primary endpoint was the incidence of severe OXCPN (grade 2 lasting for >7 days, or grade 3). The association of severe OXCPN and pretreatment parameters was evaluated using a multivariate regression model.

Results

Between Jan 2008 and Feb 2010, 100 patients treated with adjuvant folinic acid/fluorouracil plus oxaliplatin (FOLFOX) and 266 patients treated with capecitabine plus oxaliplatin (XELOX) or FOLFOX for advanced disease were registered into our study. The median cumulative dose of oxaliplatin was 796 mg/m² (range, 85 to 1,583 mg/m²). Severe OXCPN was observed in 126 (34%) patients. Overall, 43 patients discontinued chemotherapy due to toxicity: 23 without severe OXCPN and 20 with severe OXCPN. In univariate analysis, severe OXCPN was frequently observed in patients with age ≥55 years (p<0.01), stage II or III (p<0.01), adjuvant setting (p=0.01), FOLFOX (p<0.01), performance status of 0 (p=0.02), and those with no prior chemotherapy (p<0.01). In a multivariate regression model, the number of chemotherapy cycles and the cumulative oxaliplatin dose were not associated with the development of severe OXCPN.

Conclusion

We failed to find a significant association between patient characteristics at baseline and the development of severe OXCPN after oxaliplatin-based combination chemotherapy. Pharmacogenomic profiling using genome-wide association study in these patients is underway.

Oxaliplatin-Related Ocular Toxicity

We report the case of a 52-year-old woman with advanced colorectal cancer who was treated with oxaliplatin on a FOLFOX schedule. After 3 cycles of chemotherapy, she started to complain of visual loss, altered color vision and neurological symptoms. Due to the suspicion of ocular and neurological toxicity, antineoplastic treatment was stopped. Her visual field showed a concentric bilateral scotoma and the electrooculogram test revealed severe impairment of the retinal pigment epithelium. Visual acuity, color vision and visual field recovered completely 8 months later, although electrooculogram remained abnormal. Ocular toxicity has been reported as an infrequent adverse event of oxaliplatin. Findings in this case indicate toxicity of this chemotherapeutic agent on the retinal pigment epithelium, which has not been reported before. This damage could be permanent, and it thus differs from previously described oxaliplatin-induced ocular toxicities, which are usually transient and reversible. With increasing use of oxaliplatin as first-line treatment in advanced colorectal cancer, we have to be aware of this possible toxicity.

Pyridoxine to protect from oxaliplatin-induced neurotoxicity without compromising antitumour effect

PURPOSE

Oxaliplatin (OHP) in combination with 5-fluorouracil/leucovorin (FOLFOX) is clinically used as frontline therapy in patients with advanced colorectal carcinoma (CRC), with response rates ranging from 46 to 71%. This combination is now considered a standard treatment for metastatic CRC and also in the post-operative adjuvant setting. Reversible, cumulative, peripheral sensory neuropathy is the principal dose-limiting toxicity of OHP therapy. Pyridoxine (vitamin B6) has been shown to reduce cisplatin and fluoropyrimidine-related neurotoxicity but its administration with OHP has not yet been studied. Low doses of pyridoxine are free of side effects; it can be given orally. If pyridoxine administration with oxaliplatin has no adverse effect on OHP cytotoxicity effects, it will be a simple and cost-effective way to minimise OHP-induced neurotoxicity.

METHODS

In vitro simultaneous combination of OHP and pyridoxine was studied in 6 CRC cell lines (HT29, Widr, SW480, HCT116, H630 and SW1116), in an ovarian cancer cell line (A2780) and its cisplatin-resistant subline (ADDP) and in an oestrogen-dependent breast cancer cell line (MCF-7). Three fixed concentrations of pyridoxine: 1, 10 and 25 μM were combined with varying concentrations of OHP, and the growth inhibitory effects were evaluated using the MTT cell growth assay.

RESULTS

Oxaliplatin induced consistent cytotoxicity in all cell lines with GI(50) values between 0.23 and 7.6 μM. Addition of pyridoxine at concentrations of 1-25 μM does not affect OHP cytotoxicity.

CONCLUSIONS

Administration of pyridoxine, at concentrations extending across possible therapeutic plasma levels in humans, does not antagonise OHP antitumour effects in a range of relevant tumour cell lines. This study provides a foundation for clinical studies to test whether pyridoxine can minimise OHP-related neurotoxicity, and clinicians can be confident that pyridoxine is very unlikely to reverse the antitumour effects of OHP, as seems to be the case with Ca/Mg infusions. This could prove to be a cost-effective way to minimise OHP-related neurotoxicity, allowing more effective less toxic treatment and better outcomes in patients.

Preference values associated with stage III colon cancer and adjuvant chemotherapy

PURPOSE

To elicit preference values for health states associated with Stage III colon cancer (CRC) and to explore the effect of neuropathy associated with current adjuvant treatment.

METHODS

We used time trade-off (TTO) techniques to elicit preferences from 49 CRC patients and 49 community members. We elicited preferences for 7 health states: remission; adjuvant therapy with no, mild, moderate, and severe neuropathy; metastatic stable; and metastatic progressive disease. Mean TTO values were adjusted for the covariates age, education, and current health.

RESULTS

Patients' adjusted mean TTO value for remission was 0.83; adjuvant chemotherapy health states ranged from 0.48 to 0.61. Significant differences were observed for both patient and community groups between TTO for remission and all adjuvant health states (P < 0.001), and between adjuvant therapy with no neuropathy and metastatic health states (P < or = 0.001). Across all health states, patients' values were on average 0.12 higher than community members (P < 0.05).

CONCLUSIONS

The findings highlight the trade-offs between the disutility of adjuvant treatment, the higher utility of remission, and the severe utility loss during metastatic disease. The preference values obtained from this study will be useful for informing patients' treatment decisions and payer cost-utility analyses of adjuvant treatment for colon cancer.

SR 57746A/xaliproden, a non-peptide neurotrophic compound: prospects and constraints for the treatment of nervous system diseases

Neurodegenerative disorders such as Alzheimer's disease or amyotrophic lateral sclerosis as well as peripheral neuropathies are difficult to treat due to a limited range of effective drugs. Neurotrophic growth factors promote neuronal survival and differentiation and could hence be interesting tools to treat these diseases. Their therapeutic use is limited due their short half-life, their inability to cross the BBB and potential side effects including tumor promotion. SR 57746A is a non-peptide, orally active compound that exhibits neuroprotective effects in various model systems in vitro and in vivo. SR 57746A shows--amongst other activities--agonistic activity on 5-HT(1A) receptors. Several clinical trials examined SR 57746A in patients with Alzheimer's disease, amyotrophic lateral sclerosis or chemotherapy-induced peripheral sensory neuropathy. This article reviews the preclinical and clinical data on SR 57746A and points out potential future applications of this compound. However, due to disapointing results in phase III trials, Sanofi-Aventis recently decided to discontinue the development of this drug.

Amelioration of oxaliplatin neurotoxicity by drugs in humans and experimental animals: a minireview of recent literature

The broad spectrum anti-neoplastic drug oxaliplatin is a third-generation platinum compound that inhibits DNA synthesis, mainly by causing intrastrandal cross-links in DNA. The drug is particularly useful alone and in combination with fluoruracil and leucovorin in colorectal cancer, but it is also used for other cancers such as those of the ovary, lung, breast and liver, as well as non-Hodgkin's lymphoma. The drug is known to cause neurological, gastrointestinal and haematological toxicities. Neurotoxicity occurs in most of the treated patients and is considered to be a serious limitation for the use of the drug. The mechanism of the neurotoxicity is not known with certainty but may involve prolongation of sodium channels opening. Strategies to ameliorate oxaliplatin neurotoxicity include the use of several 'neuroprotective' drugs. This MiniReview attempts to list and comment on the action and use of some of these agents, which include carbamazepine, gabapentin, calcium and magnesium salts, reduced glutathione, N-acetylcysteine and a few others. None of these drugs have been proven to be effective in large, controlled, clinical trials.

Heated (37 degrees C) oxaliplatin infusion in combination with capecitabine for metastatic colorectal carcinoma: can it reduce neuropathy?

BACKGROUND/PURPOSE

Oxaliplatin-associated neuropathy remains a dose-limiting toxicity of the standard chemotherapy regimen of oxaliplatin and capecitabine for metastatic colorectal cancer. No preventive strategy has definitively been established. Because this neuropathy is triggered by cold, we hypothesized that infusing oxaliplatin at 37 degrees C might reduce neuropathy.

METHODS

In this open-label pilot feasibility trial, patients with no prior chemotherapy for metastatic colorectal cancer were included. Treatment consisted of capecitabine 1,000 mg/m(2) bid on days 1-14 and oxaliplatin 130 mg/m2 on day 1 of a 21-day cycle. The oxaliplatin infusion was administered through a fluid-warming device at a constant temperature of 37 degrees C over 2 h. The primary endpoint was feasibility and drug reactions during the infusion. Secondary endpoints included acute and chronic neuropathy as well as response rate.

RESULTS

Twenty patients were enrolled, and a total of 95 cycles administered. Median cumulative oxaliplatin dose was 735 mg/m(2). Apart from one patient with laryngeal spasm, no other infusion-related adverse events were observed. Of the patients, 35% reported grade 3/4 acute dysesthesia or paresthesia according to a patients questionnaire. Chronic neuropathy according to NCI CTC v3.0 was observed in 85% (grade 1) and 15% (grade 2), respectively. The overall response rate was 45% (95% CI 23-67%; 5% complete remission; 40% partial remission) and stable disease was achieved in another 30% of patients.

CONCLUSION

Administration of heated oxaliplatin in combination with capecitabine is feasible and well tolerated without additional toxicity. While we have observed a relatively low rate of chronic cumulative neuropathy with heated oxaliplatin, this procedure appears not promising enough for us to recommend its further clinical evaluation.

Toxic effects and their management: daily clinical challenges in the treatment of colorectal cancer

Among the many chemotherapeutic options for metastatic colorectal cancer, none has shown clear superiority in efficacy. All pharmacologic agents in current use have been associated with adverse events. Frequently reported adverse events associated with the chemotherapeutic agents oxaliplatin, irinotecan, 5-fluorouracil, and capecitabine include acute and chronic neuropathy, hypersensitivity reactions, diarrhea, neutropenia, and hand-foot syndrome. Although biologic agents are seemingly less toxic, toxic effects can also arise with their use; antiangiogenic agents result in hypertension, and EGFR inhibitors can cause severe hypersensitivity, paronychial infections, and more commonly, dermatologic rash. Furthermore, a correlation has been reported for the efficacy of anti-EGFR agents and development of rash. Data indicate that elderly patients with colorectal cancer who have adequate function and performance status, who may previously have been dissuaded from pursuing active therapy solely on the basis of age, should receive the same treatment as younger patients. To enhance the survival of patients with metastatic colorectal cancer, many therapies are administered. Recognition of treatment-emergent toxic effects will, therefore, aid the design and implementation of management strategies that minimize treatment interruption and/or discontinuation, and enhance quality of life for patients.

Incidence and characteristics of peripheral neuropathy during oxaliplatin-based chemotherapy for metastatic colon cancer

AIM

The current prospective study sought to trace the incidence and severity of oxaliplatin-induced peripheral neuropathy (OXLIPN) and to determine its clinical and electrophysiological pattern.

PATIENTS AND METHODS

Twenty-five adult patients scheduled to be treated with 12 courses of the oxaliplatin-based regimen, FOLFOX-4, for metastatic colon cancer participated in this study. Patients were clinically and electrophysiologically monitored at baseline and followed-up during chemotherapy. The severity of OXLIPN was summarized by means of a modified Total Neuropathy Score (TNS).

RESULTS

Evidence of OXLIPN was disclosed in 16 of the 25 patients (64%). The mean TNS values for patients manifesting some grade of OXLIPN were 13.9 +/- 5.8 (range 7-28). All longitudinal comparisons concerning the motor conduction parameters failed to reach significance. By contrast, comparisons of the median changes at baseline and each of the follow-up studies revealed significant decrease in all sensory action potentials examined.

CONCLUSION

Our results indicate that the majority of patients treated with the FOLFOX-4 regimen would manifest an axonal, predominately sensory peripheral neuropathy, of mild to moderate severity.

Improved overall survival with oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial

PURPOSE Three-year disease-free survival (DFS) was significantly improved in patients who had undergone resection with curative intent for stage II or III colon cancer who received bolus plus continuous-infusion fluorouracil plus leucovorin (LV5FU2) with the addition of oxaliplatin (FOLFOX4). Final results of the study, including 6-year overall survival (OS) and 5-year updated DFS, are reported. PATIENTS AND METHODS A total of 2,246 patients were randomly assigned to receive LV5FU2 or FOLFOX4 for 6 months. The primary end point was DFS. Secondary end points were OS and safety. Results Five-year DFS rates were 73.3% and 67.4% in the FOLFOX4 and LV5FU2 groups, respectively (hazard ratio [HR] = 0.80; 95% CI, 0.68 to 0.93; P = .003). Six-year OS rates were 78.5% and 76.0% in the FOLFOX4 and LV5FU2 groups, respectively (HR = 0.84; 95% CI, 0.71 to 1.00; P = .046); corresponding 6-year OS rates for patients with stage III disease were 72.9% and 68.7%, respectively (HR = 0.80; 95% CI, 0.65 to 0.97; P = .023). No difference in OS was seen in the stage II population. The incidence of second noncolorectal cancers was 5.5% and 6.1% in the FOLFOX4 and LV5FU2 groups, respectively. Among patients receiving oxaliplatin, the frequency of grade 3 peripheral sensory neuropathy was 1.3% 12 months after treatment and 0.7% at 48 months. CONCLUSION Adding oxaliplatin to LV5FU2 significantly improved 5-year DFS and 6-year OS in the adjuvant treatment of stage II or III colon cancer and should be considered after surgery for patients with stage III disease.

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

Background

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

Results

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

Conclusion

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

Symptom burden in cancer survivorship

INTRODUCTION

The subjective experience of cancer survivorship can be assessed by various patient-reported outcome (PRO) methods, including measures of symptom burden and health-related quality of life (HRQOL). Symptom burden includes the presence and severity of multiple symptoms and the level of distress caused by symptoms that go untreated or unrelieved. The concept of symptom burden is more limited in scope than HRQOL but may provide information that better describes the status of various stages of survivorship. This paper contrasts symptom burden with general HRQOL and addresses the importance of including symptom burden as research tool throughout the trajectory of cancer survivorship.

METHODS

We summarized studies that illustrate both HRQOL and symptoms as outcomes of treatment and of descriptive studies of cancer survivorship. Survivorship was operationally defined as beginning at the completion of primary anticancer treatment.

RESULTS

HRQOL and symptom burden measures both provide meaningful but conceptually different data. Both types of measures are important in portraying aspects of cancer survivorship over time, although symptom burden may provide sufficient information to inform treatment decisions and identify long-term effects of cancer therapies.

CONCLUSIONS

Cancer survivors are at risk for multiple severe and persistent symptoms, and assessing and monitoring the severity and impact of these multiple symptoms is critical to understanding the survivorship experience. The inclusion of multiple symptom measures along with the development of new and better methods of long-term symptom tracking in survivors is a critical step in improving the heath status of survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Late and long-term effects seen in cancer survivors have historically been understudied. Symptom burden is an important area of assessment that can be used to specifically describe the symptoms that distress survivors. More descriptive data in this growing population may help identify biological processes in symptom production and maintenance, and facilitate in the development of better treatment and prevention to enhance cancer survivorship.

Comparative antiallodynic activity of morphine, pregabalin and lidocaine in a rat model of neuropathic pain produced by one oxaliplatin injection

A single infusion of oxaliplatin, a drug active against colorectal cancer, induces specific painful syndrome characterized by neurosensitive symptoms triggered or aggravated in cold conditions. In an animal model that reproduces such hypersensitivity to cold for five days after a single oxaliplatin administration (6mg/kg, i.p.), we assessed the antinociceptive efficacy of intravenously administered drugs such as morphine, lidocaine and pregabalin using the rat tail immersion test in cold water (10 degrees C). The antinociceptive efficacy was first ranked by ratio of the pharmacological effect (versus time) to dose: pregabalin (2mg/kg)>lidocaine (3mg/kg)>morphine (4mg/kg). Our results show that pregabalin may be a good choice to treat cold hypersensitivity after one oxaliplatin injection.

Phase I study of capecitabine and oxaliplatin in combination with the proteasome inhibitor bortezomib in patients with advanced solid tumors

PURPOSE

The combination of capecitabine and oxaliplatin has clinical benefit in a variety of gastrointestinal malignancies. The proteasome inhibitor bortezomib enhances the cytotoxic activity of fluoropyrimidines and platinum agents in vivo, and targeting of NF-kappaB may overcome chemotherapy resistance. Thus, we performed this phase I study to document the safety and obtain preliminary efficacy data for the combination of capecitabine, oxaliplatin, and bortezomib.

PATIENTS AND METHODS

Patients with advanced solid tumors were treated with oxaliplatin 130 mg/m(2) intravenously on day 1, capecitabine 750-900 mg/m(2) twice daily orally for 14 days, and bortezomib 1.0, 1.3, or 1.6 mg/m(2) intravenously on days 1 and 8 of 21 day cycles. CT scans were repeated every 2 cycles.

RESULTS

Thirteen patients received 45 cycles of treatment (median, 2; range, 1-8). No dose-limiting toxicities were noted at all bortezomib dose levels when administered with full dose capecitabine and oxaliplatin. The most common grade 3 nonhematologic toxicities during any cycle of therapy included elevated transaminases (3), vomiting, diarrhea, and dehydration (2 each). Only one patient experienced grade 3 peripheral neuropathy in cycle 8. Three objective tumor responses were noted (squamous cell of anus, adenocarcinoma of unknown primary, adenocarcinoma of rectum).

CONCLUSIONS

Weekly bortezomib can be safely combined with full doses of capecitabine and oxaliplatin. As 1.6 mg/m(2) weekly of bortezomib is the maximum tolerated dose in single-agent studies, no further dose escalation was performed in this study. Preliminary evidence of antitumor activity is demonstrated. The further evaluation of this combination in diseases for which capecitabine and oxaliplatin have efficacy should be considered.

A review on oxaliplatin-induced peripheral nerve damage

Platinum compounds are a class of chemotherapy agents that posses a broad spectrum of activity against several solid malignancies. Oxaliplatin (OXL) is a third-generation organoplatinum compound with significant activity mainly against colorectal cancer (CRC). Peripheral neuropathy is a well recognized toxicity of OXL, usually resulting in dose modification. OXL induces two types of peripheral neuropathy; acute and chronic. The acute oxaliplatin-induced peripheral neuropathy (OXLIPN) may be linked to the rapid chelation of calcium by OXL-induced oxalate and OXL is capable of altering the voltage-gated sodium channels through a pathway involving calcium ions. On the other hand, decreased cellular metabolism and axoplasmatic transport resulting from the accumulation of OXL in the dorsal root ganglia cells is the most widely accepted mechanism of chronic oxaliplatin-induced peripheral neuropathy (OXLIPN). As a result, OXL produces a symmetric, axonal, sensory distal primary neuronopathy without motor involvement. The incidence of OXLIPN is usually related to various risk factors, including treatment schedule, dosage, cumulative dose and time of infusion. The assessment of OXLIPN is primarily based on neurologic clinical examination and quantitative methods, such as nerve conduction study. To date, several neuroprotective agents including thiols, neurotrophic factors, anticonvulsants and antioxidants have been tested for their ability to prevent OXLIPN. However, the clinical data are still controversial. We herein review and discuss the pathogenesis, incidence, risk factors, diagnosis, characteristics and management of OXLIPN. We also highlight areas of future research.

Peripheral Neuropathy Related to Chemotherapy

OBJECTIVES

To review the evidence base for prevention and intervention of chemotherapy-induced peripheral neuropathy (PN).

DATA SOURCES

Medical and nursing literature.

CONCLUSION

Many small studies that reported positive findings have either not been validated in large prospective, randomized controlled trials (RCT), or have not been further studied. Prevention strategies based on RCTs include the use of xaliproden to reduce the incidence of grade 3 PN in patients receiving oxaliplatin-based regimens, and dose reduction or interruption until recovery. There are gaps in the literature of nurse-sensitive outcome studies for nursing assessment and intervention

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be knowledgeable about the evidence, or lack of it, on strategies to prevent and manage chemotherapy-induced PN. Nurses also need to measure the effectiveness of interventions for PN, such as exercise, patient teaching about self-care strategies, and develop and/or participate in well-designed intervention studies regarding the prevention and management of PN.

Oxaliplatin for the treatment of cisplatin-resistant cancer: A systematic review

Oxaliplatin is widely regarded as being active in cisplatin-resistant cancer. We undertook a systematic review of the literature to identify, describe and critique the clinical and pre-clinical evidence for the use of oxaliplatin in patients with "cisplatin-resistant" cancer. We identified 25 pre-clinical cell models of platinum resistance and 24 clinical trials reporting oxaliplatin based salvage therapy for cisplatin-resistant cancer. The pre-clinical data suggests that there is cross-resistance between cisplatin and oxaliplatin in low-level resistance models. In models with high level resistance (>10-fold) there is less cross-resistance between cisplatin and oxaliplatin, which may be a reason why oxaliplatin is thought to be active in cisplatin-resistant cancer. In clinical trials where oxaliplatin has been used as part of salvage therapy for patients who have failed cisplatin or carboplatin combination chemotherapy, there was a much lower response rate in patients with platinum-refractory or resistant cancers compared to platinum-sensitive cancers. This suggests that there may be cross-resistance between cisplatin and oxaliplatin in the clinic. Oxaliplatin as a single agent had a poor response rate in cisplatin refractory and resistant cancer. Oxaliplatin performed better in combination with other agents for the treatment of platinum-resistant/refractory cancer suggesting that the benefit of oxaliplatin may lie in its more favourable toxicity and ability to be combined with other drugs rather than an underlying activity in cisplatin resistance. Oxaliplatin therefore should not be considered broadly active in cisplatin-resistant cancer.

Behavioral and immunohistological assessment of painful neuropathy induced by a single oxaliplatin injection in the rat

In clinical use, a single infusion of oxaliplatin, widely used to treat metastatic colorectal cancer, induces specific sensory neurotoxicity signs triggered or aggravated by exposure to cold. To study the pathophysiology of these symptoms, we developed and characterized an animal model that reproduces the effects of a single intraperitoneal oxaliplatin administration (3, 6 and 12 mg/kg). Significant allodynia and hyperalgesia to cold stimuli were rapidly observed from 24 h to day 5 with a maximum lowering of 76% at t+30 h versus control. Other behavioral assessments revealed rapid persistent mechanical allodynia, but no thermal hyperalgesia or allodynia to heat and no hyperalgesia to mechanical stimuli. An immunohistochemical study in the superficial layers of the spinal dorsal horn revealed a marked increase in substance P immunoreactivity versus controls (12% versus 4%), whereas calcitonin gene-related peptide (CGRP) immunoreactivity was unchanged. This new animal model for the first time closely mimics the effects observed in humans after a single oxaliplatin infusion, especially onset and highly intense sensory disturbances, hypersensitivity to cold with allodynia and hyperalgesia signs. This model may help to elucidate the mechanisms of this thermal hypersensitivity, especially the possible involvement of small-diameter A-fibers in cold allodynia symptoms. These selective effects may clue up the mechanistic basis for the acute oxaliplatin neuropathy leading to a better understanding of the clinical condition and to optimize its treatment.

Behavioral and pharmacological description of oxaliplatin-induced painful neuropathy in rat

We describe an animal model of nociceptive sensory neuropathy induced by repeat intravenous administration of oxaliplatin in which treated animals partly reproduce the characteristic pain symptoms in oxaliplatin-treated patients. We tested the ability of 1, 2 and 4 mg/kg oxaliplatin doses injected twice-weekly for four-and-a-half consecutive weeks to induce a nociceptive peripheral neuropathy in male Sprague-Dawley rats. The behavioral assessment revealed cold allodynia (10 degrees C) and hyperalgesia (4 degrees C) symptoms associated with a mechanical allodynia. The rats maintained a good general clinical status without motor dysfunction. The 2mg/kg oxaliplatin dose and the tail-immersion test in cold water (10 degrees C) were selected to compare pharmacological sensitivity between single administered drugs as morphine, lidocaine, carbamazepine, gabapentin and repeated administration of drugs as clomipramine, venlafaxine, calcium and magnesium solutions. Magnesium solution (90 mg/kg) and venlafaxine (7.5 mg/kg) administration induced an antinociceptive effect whereas gabapentin (300 mg/kg), clomipramine (2.5 mg/kg) and lidocaine (3 and 6 mg/kg) only induced an antiallodynic effect.

Neuroprotection during chemotherapy: a systematic review

The development of neurotoxicity during antineoplastic therapy is one of the most common reasons for termination or modification of cancer treatment. A number of different agents have been proposed to provide neuroprotection without affecting antitumor efficacy. This review provides an evidence-based summary of neuroprotective medicines, an overview of the literature relating to neuroprotection during cancer treatment and a Neurologist perspective risk assessment and management. Through a systematic review the authors identified 49 papers published to date that report human clinical trials involving potential neuroprotectants in adults. Case reports and series completed in a prospective fashion were also included. Sensory neuropathies were the most prevalent subtype in the literature, and most were at least partially reversible with or without neuroprotective treatment. The majority of study medications had minimal side effects, though 2 trials were prematurely terminated because of adverse patient outcomes. No study reported an effect on antitumor efficacy. Because of the variability in study design, cancer type, outcome measures, and clinical confirmation of neuropathy, meta-analysis could not be appropriately performed. We highlight risk factors and discuss neuropathy screening. Descriptive analysis is provided which reveals that many of the agents studied were likely to confer some at least some neuroprotective benefit.

A phase IB, open-label dose-escalating study of the oral angiogenesis inhibitor PTK787/ZK 222584 (PTK/ZK), in combination with FOLFOX4 chemotherapy in patients with advanced colorectal cancer

BACKGROUND

This open-label, phase IB study was undertaken to determine the safety/toxicity profile and recommended dose of oral once-daily PTK787/ZK 222584 (PTK/ZK) combined with oxaliplatin/5-fluorouracil (5-FU)/leucovorin (FOLFOX4) chemotherapy in patients with advanced colorectal cancer. Secondary objectives were to assess full pharmacokinetics and gather preliminary evidence of antitumor activity.

PATIENTS AND METHODS

Thirty-five patients received escalating doses of PTK/ZK (range 500-2000 mg daily) continuously. Concurrent FOLFOX4 chemotherapy was administered on days 1 and 2 and repeated every 14 days. Dose escalation of PTK/ZK was continued until maximum tolerated dose (MTD) was established and additional patients were then enrolled at MTD dosage.

RESULTS

Mean treatment duration of PTK/ZK was 9.5 months. The MTD was 1250 mg daily with dizziness being the most frequent dose-limiting toxicity (DLT). Hypertension (23%, grade 3) and neutropenia (37%, grades 3 + 4) were the most frequent grade 3 or 4 adverse events. Pharmacokinetic analyses found no evidence for interactions between PTK/ZK and the combination of 5-FU, leucovorin, and oxaliplatin during concomitant use. Median progression-free survival was 11.4 months.

CONCLUSION

The MTD of PTK/ZK in combination with FOLFOX4 in this patient population is 1250 mg daily. The combination is feasible and safe and is not associated with significant pharmacokinetic interactions.

Molecular mechanisms of resistance and toxicity associated with platinating agents

Platinating agents, including cisplatin, carboplatin, and oxaliplatin, have been used clinically for nearly 30years as part of the treatment of many types of cancers, including head and neck, testicular, ovarian, cervical, lung, colorectal and relapsed lymphoma. The cytotoxic lesion of platinating agents is thought to be the platinum intrastrand crosslink that forms on DNA, although treatment activates a number of signal transduction pathways. Treatment with these agents is characterized by resistance, both acquired and intrinsic. This resistance can be caused by a number of cellular adaptations, including reduced uptake, inactivation by glutathione and other anti-oxidants, and increased levels of DNA repair or DNA tolerance. Here we investigate the pathways that treatment with platinating agents activate, the mechanisms of resistance, potential candidate genes involved in the development of resistance, and associated clinical toxicities. Although the purpose of this review is to provide an overview of cisplatin, carboplatin, and oxaliplatin, we have focused primarily on preclinical data that has clinical relevance generated over the past five years.

Carbamazepine for prevention of oxaliplatin-related neurotoxicity in patients with advanced colorectal cancer: Final results of a randomised, controlled, multicenter phase II study

BACKGROUND

Oxaliplatin-induced neurotoxicity is a growing, relevant clinical problem. In this study we evaluated the efficacy and safety of carbamazepine for prevention of oxaliplatin-associated neuropathy in patients with advanced colorectal cancer.

METHODS

Chemotherapeutic treatment consisted of oxaliplatin 85 mg/m(2) given biweekly and weekly folinic acid 500 mg/m(2) followed by a 24-h infusion of 5-FU 2000 mg/m(2) (FUFOX). One cycle consisted of six consecutive weeks of treatment followed by two weeks of rest (=Treatment B). For Treatment A carbamazepine was added in a dosage for targeted plasma levels of 4-6 mg/L. Neurotoxicity was regularly assessed using a specific scale. Moreover, an evaluation of chronic sensory symptoms and a neurologic examination including tests for vibrational sense, strength and deep tendon reflexes were added creating a peripheral neuropathy (PNP) score.

RESULTS

The prospectively defined adequate number of patients needed to provide power for the primary outcome could not be achieved. 19 patients were assigned to Treatment A and 17 to Treatment B. At baseline, the distribution of all clinicopathologic variables was comparable between the two groups. Overall response rates were 16% and 24% and overall survival 15.1 months and 17.4 months for Treatment A and Treatment B, respectively. Between Treatment A and Treatment B there were no major differences when considering worst neurotoxicity during the study period (p=0.46). Grade 3/4 neurotoxicity occured in 4 patients with Treatment A vs. 6 patients with Treatment B. There were no major differences between both groups in each category of the PNP score.

CONCLUSIONS

Based on the small number of patients and low statistical power of our study definite conclusions regarding efficacy and safety of carbamazepine for prevention of oxaliplatin-associated neuropathy in patients with advanced colorectal cancer cannot be drawn.

Persistence of High-Dose Oxaliplatin-Induced Neuropathy at Long-Term Follow-Up

Oxaliplatin (L-OHP) has become a standard treatment for advanced colorectal cancer and a valid option for patients in the adjuvant setting. Compared with cisplatin, L-OHP has no renal toxicity, only mild hematological and gastrointestinal toxicity, while neurotoxicity is the limiting toxicity. This side effect has been described as a transient distal dysesthesia, enhanced by exposure to cold, and as a dose-related cumulative mild sensitive neuropathy. We studied two groups of patients (18 and 13) with advanced colorectal cancer, treated with median cumulative doses of L-OHP 862 mg/m2 and 1,033.5 mg/m2. All the patients had been evaluated previously, during treatment, after discontinuation and after a long follow-up of 5 years to verify the incidence and the characteristics of the neuropathy induced by this antineoplastic agent. The clinical and neurophysiological examinations showed an acute and transient neurotoxicity and a cumulative dose-related sensory neuropathy in nearly all the patients. The reversibility of these effects was studied. Five patients continue to manifest symptoms and signs of neurotoxicity after a long follow-up, indicating persistence of this peculiar type of neuropathy.

Clinical application of oxaliplatin in epithelial ovarian cancer

Platinum remains the most active drug class in ovarian cancer treatment; however, new single-agent and combination therapies are needed to improve the clinical outcome of ovarian cancer therapies. Oxaliplatin, a third-generation platinum derivative, has shown effective antitumor activity and a favorable toxicity profile in epithelial ovarian cancer. Preclinical evidence of the synergistic cytotoxic effect of oxaliplatin in combination with several other chemotherapeutic agents and clinical evidence of the absence of any dose-limiting hematologic toxicity associated with this agent have made oxaliplatin an attractive compound for combination agent therapy. This article reviews the current status of the clinical application of oxaliplatin alone and in a combination regimen in epithelial ovarian cancer treatment.

Oxaliplatin-related neurotoxicity: how and why?

In early clinical trials, oxaliplatin has demonstrated significant activity against colorectal cancer in combination with 5-fluorouracil (5-FU) and folinic acid (FA), both in metastatic as in radically resected disease. The drug differs from the other two most important platinum compounds (cisplatin and carboplatin) for the absence of nephrotoxicity or for the reduced drug-induced ototoxicity. During its administration, two different types of neurological symptoms can be experienced: the first one occurs during or immediately after the end of the infusion and it appears as a transient peripheral sensory neuropathy manifesting as paresthesias and dysesthesia in the extremities sometimes accompanied by muscular contractions of the extremities or the jaw (triggered or enhanced by exposure to cold). The second one occurs after long-term administration of oxaliplatin presenting with deep sensory loss, sensory ataxia and functional impairment (similar to those observed with cisplatin). This type of neurotoxicity is usually late-onset and correlated with the cumulative-dose of oxaliplatin. The aim of this review is to analyse the mechanism underlying induction of neurotoxicity and the possible treatments to prevent and to treat it.

Delayed oxaliplatin-associated neurotoxicity following adjuvant chemotherapy for stage III colon cancer

Oxaliplatin-containing chemotherapy regimens are utilized commonly for metastatic colorectal cancer and increasingly in the adjuvant setting following surgical resection. The dose-limiting toxicity is neurotoxicity. Acute neurotoxicity is cold induced and transient. Chronic neurotoxicity usually has a predictable clinical course. It is manifested by paresthesias and dysesthesias of gradually prolonged duration that occur between treatment cycles, and increase in intensity and duration with the cumulative dose. We report here a case of a patient who developed significant grade 3 chronic neuropathy following completion of 6 months of adjuvant oxaliplatin-containing chemotherapy for stage III colon cancer. The neurotoxicity was not preceded by any transient symptoms characteristic of chronic oxaliplatin neuropathy and its onset was unpredictable. Delayed neurotoxicity is a complication which must be considered for patients receiving adjuvant therapy and attempts to utilize the minimum effective cumulative dose of oxaliplatin are warranted.