Use of calcium and magnesium infusions in prevention of oxaliplatin induced sensory neuropathy

Curcumin: A Novel Way to Improve Quality of Life for Colorectal Cancer Patients?

Colorectal cancer (CRC) is the third most common cancer in men and the second most common in women. Treatment of metastatic CRC consists of highly toxic chemotherapeutic drug combinations that often negatively affect patient quality of life (QoL). Moreover, chemotherapy-induced toxicity and chemotherapy resistance are among the most important factors limiting cancer treatment and can lead to the interruption or discontinuation of potentially effective therapy. Several preclinical studies have demonstrated that curcumin acts through multiple cellular pathways and possesses both anti-cancer properties against CRC and the capacity to mitigate chemotherapy-related side effects and overcome drug resistance. In this review article, we suggest that the addition of curcumin to the standard chemotherapeutic treatment for metastatic CRC could reduce associated side-effects and overcome chemotherapy resistance, thereby improving patient QoL.

Prevention of Oxaliplatin-Induced Peripheral Neuropathy: A Systematic Review and Meta-Analysis

Background

Oxaliplatin-induced peripheral neuropathy (OIPN) has significant clinical impact on the quality of life for cancer patients and is a dose limiting toxicity. Trials studying preventive measures have been inconclusive. A systematic review and meta-analysis were conducted to evaluate the existing pharmacological and non-pharmacological interventions to prevent chronic OIPN.

Methods

Literature databases PubMed-MEDLINE, Embase and Scopus, were searched from 1 Jan 2005 to 08 Aug 2020 and major conferences’ abstracts were reviewed for randomized controlled trials that examined the efficacy of any preventive measure for OIPN. The primary outcome measure was the incidence of chronic OIPN with a preventive intervention as compared to placebo or no intervention. The pooled risk ratio and its 95% confidence interval were calculated using a random effects model. A network meta-analysis was conducted to derive indirect evidence of any preventive effect of an intervention against placebo when original trials compared one intervention against another.

Results

Forty-four trials were analyzed describing 29 chemoprotective interventions, including combinations, and 1 non-pharmacological intervention. Ratings were assessed via a combination of outcomes with quality assessment using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. Of the 30 interventions examined, there were six interventions supporting potential efficacy, 11 interventions with insufficient evidence and 13 interventions not recommended.

Conclusion

Currently, there is insufficient certainty to support any intervention as effective in preventing OIPN. Of note is that most of these studies have focused on pharmacological interventions; non-pharmacological interventions are underexplored. Further research on ways to limit OIPN is needed.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=225095, Prospero Registration Number: CRD42021225095.

Magnesium and Pain

In terms of antinociceptive action, the main mode of action of magnesium involves its antagonist action at the N-methyl-d-aspartate (NMDA) receptor, which prevents central sensitization and attenuates preexisting pain hypersensitivity. Given the pivotal function of NMDA receptors in pain transduction, magnesium has been investigated in a variety of pain conditions. The oral and parenteral administration of magnesium via the intravenous, intrathecal, or epidural route may alleviate pain and perioperative anesthetic and analgesic requirements. These beneficial effects of magnesium therapy have also been reported in patients with neuropathic pain, such as malignancy-related neurologic symptoms, diabetic neuropathy, postherpetic neuralgia, and chemotherapy-induced peripheral neuropathy. In addition, magnesium treatment is reportedly able to alleviate fibromyalgia, dysmenorrhea, headaches, and acute migraine attacks. Although magnesium plays an evolving role in pain management, better understanding of the mechanism underlying its antinociceptive action and additional clinical studies is required to clarify its role as an adjuvant analgesic.

Potential Use of Gluconate in Cancer Therapy

We have recently discovered that cancer cells take up extracellular citrate through plasma membrane citrate transporter (pmCiC) and advantageously use citrate for their metabolism. Citrate uptake can be blocked with gluconate and this results in decreased tumor growth and altered metabolic characteristics of tumor tissue. Interestingly, gluconate, considered to be physiologically neutral, is incidentally used in medicine as a cation carrier, but not as a therapeutically active substance. In this review we discuss the results of our recent research with available literature and suggest that gluconate may be useful in the treatment of cancer.

In Search of a Gold Standard Patient-Reported Outcome Measure for Use in Chemotherapy- Induced Peripheral Neuropathy Clinical Trials

Purpose:

To test a reduced version—CIPN15—of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy scale (QLQ-CIPN20) to establish a possible gold-standard patient-reported outcome measure for chemotherapy-induced peripheral neuropathy (CIPN).

Methods:

Using a prospective, longitudinal, case–control design, patients (n = 121) receiving neurotoxic chemotherapy completed the CIPN15 at baseline and 12 weeks and underwent objective neurological assessment using the 5-item Total Neuropathy Score-Clinical (TNSc). Healthy controls (n = 30) completed the CIPN15 once. Structural validity was evaluated using factor analysis. Because a stable factor structure was not found, a sum score was used to evaluate measures of the CIPN15’s psychometric properties—reliability, validity, sensitivity, and responsiveness—as follows: internal consistency via Cronbach’s α and item–item correlations; test–retest reliability via correlation between 2 CIPN15 scores from each patient; concurrent validity via correlation between CIPN15 and 5-item TNSc scores; contrasting group validity via comparison of CIPN15 scores from patients and healthy controls; sensitivity via descriptive statistics (means, standard deviation, ranges); and responsiveness via Cohen’s d effect size.

Results:

Most patients received single agent oxaliplatin (33.7%), paclitaxel (21.2%), or more than 1 neurotoxic drug concurrently (29.8%). Factor analysis revealed no stable factor structure. Cronbach’s α for the CIPN15 sum score was 0.91 (confidence interval [CI] = 0.89-0.93). Test–retest reliability was demonstrated based on strong correlations between the 2 scores obtained at the 12-week time point (r = 0.86; CI = 0.80-0.90). The CIPN15 and 5-item TNSc items reflecting symptoms (not signs) were moderately correlated (r range 0.57-0.72): concurrent validity. Statistically significant differences were found between patient and healthy control CIPN15 mean scores (P < .0001): contrasting group validity. All items encompassed the full score range but the CIPN15 linearly converted sum score did not: sensitivity. The CIPN15 was responsive based on a Cohen’s d of 0.52 (CI = 0.25-0.79).

Conclusion:

The sum-scored CIPN15 is reliable, valid, sensitive, and responsive when used to assess taxane- and platinum-induced CIPN.

Dietary Intake of Magnesium or Calcium and Chemotherapy-Induced Peripheral Neuropathy in Colorectal Cancer Patients

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and severe side-effect in colorectal cancer (CRC) patients. This study assessed the association between habitual dietary intake of magnesium or calcium and prevalence and severity of chronic CIPN in CRC patients receiving adjuvant chemotherapy. For this prospective cohort study, 196 CRC patients were considered. Magnesium and calcium intake was determined using a food frequency questionnaire at diagnosis, during and after chemotherapy. Chronic CIPN was assessed 12 months after diagnosis using the quality of life questionnaire CIPN20. Prevalence ratios were calculated to assess the association between magnesium or calcium intake and the prevalence of CIPN. Multivariable linear regression analysis was used to assess the association between magnesium or calcium intake and severity of CIPN. CIPN was reported by 160 (82%) patients. Magnesium intake during chemotherapy was statistically significantly associated with lower prevalence of CIPN (prevalence ratio (PR) 0.53, 95% confidence interval (CI) 0.32, 0.92). Furthermore, higher dietary intake of magnesium during (β −1.08, 95% CI −1.95, −0.22) and after chemotherapy (β −0.93, 95% CI −1.81, −0.06) was associated with less severe CIPN. No associations were found for calcium intake and the prevalence and severity of CIPN. To conclude, we observed an association between higher dietary magnesium intake and lower prevalence and severity of CIPN in CRC patients.

Risk-reduction and treatment of chemotherapy-induced peripheral neuropathy

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN), a common adverse effect of several chemotherapeutic agents, has a significant impact on quality of life and may even compromise treatment efficacy, requiring chemotherapy dose reduction or discontinuation. CIPN is predominantly related with sensory rather than motor symptoms and the most common related cytotoxic agents are platinum compounds, taxanes and vinca alkaloids. CIPN symptoms may resolve after treatment cessation, but they can also be permanent and continue for years. Areas covered: We present an overview of CIPN pathophysiology, clinical assessment, prevention and treatment identified through a Pubmed search. Expert commentary: No substantial progress has been made in the last few years within the field of prevention and/or treatment of CIPN, in spite of remarkable efforts. Continuous research could expand our knowledge about chemotherapeutic-specific neuropathic pathways and eventually lead to the conception of innovative and targeted agents for the prevention and/or treatment of this debilitating chemotherapy adverse effect.

Efficacy of Drug Interventions for Chemotherapy-Induced Chronic Peripheral Neurotoxicity: A Network Meta-analysis

Peripheral neurotoxicity is a disturbing issue for cancer patients who are treated with chemotherapy. Several medications have been developed for preventing chemotherapy-induced chronic neurotoxicity (CICNT) however; their relative efficacies have not yet been studied. In this study, we conducted a network meta-analysis to give intervention recommendations. The literature was searched in a variety of databases and eligible studies were chosen based on predefined criteria. Data extraction and statistical analysis was performed, and the results are displayed using the odds ratio (OR) and corresponding 95% credible intervals (CrI) with respect to overall and severe neurotoxicity. The medications were ranked according to their surface under cumulative ranking curve values. The consistency of direct and indirect evidence was also evaluated. We found that patients with amifostine or vitamin E (VE) treatment exhibited a lower risk of overall neurotoxicity compared to those using the placebo (amifostine: OR = 0.10, 95% CrI: 0.02–0.46; VE: OR = 0.08, 95% CrI: 0.01–0.99). In regard to preventing severe neurotoxicity, glutathione and amifostine treatment appeared to be significantly more effective than the placebo (glutathione: OR = 0.19, 95% CrI: 0.04–0.64; amifostine: OR = 0.12, 95% CrI: 0.02–0.48). In summary, amifostine, VE, and glutathione treatment is considered to be effective in lowering the risk of CICNT. However, further studies which consider safety are required.

Platinum-induced neurotoxicity and preventive strategies: past, present, and future

Neurotoxicity is a burdensome side effect of platinum-based chemotherapy that prevents administration of the full efficacious dosage and often leads to treatment withdrawal. Peripheral sensory neurotoxicity varies from paresthesia in fingers to ataxic gait, which might be transient or irreversible. Because the number of patients being treated with these neurotoxic agents is still increasing, the need for understanding the pathogenesis of this dramatic side effect is critical. Platinum derivatives, such as cisplatin and carboplatin, harm mainly peripheral nerves and dorsal root ganglia neurons, possibly because of progressive DNA-adduct accumulation and inhibition of DNA repair pathways (e.g., extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase/stress-activated protein kinase, and p38 mitogen-activated protein kinass), which finally mediate apoptosis. Oxaliplatin, with a completely different pharmacokinetic profile, may also alter calcium-sensitive voltage-gated sodium channel kinetics through a calcium ion immobilization by oxalate residue as a calcium chelator and cause acute neurotoxicity. Polymorphisms in several genes, such as voltage-gated sodium channel genes or genes affecting the activity of pivotal metal transporters (e.g., organic cation transporters, organic cation/carnitine transporters, and some metal transporters, such as the copper transporters, and multidrug resistance-associated proteins), can also influence drug neurotoxicity and treatment response. However, most pharmacogenetics studies need to be elucidated by robust evidence. There are supportive reports about the effectiveness of several neuroprotective agents (e.g., vitamin E, glutathione, amifostine, xaliproden, and venlafaxine), but dose adjustment and/or drug withdrawal seem to be the most frequently used methods in the management of platinum-induced peripheral neurotoxicity. To develop alternative options in the treatment of platinum-induced neuropathy, studies on in vitro models and appropriate trials planning should be integrated into the future design of neuroprotective strategies to find the best patient-oriented solution.

Prevention and management of chemotherapy-induced peripheral neuropathy in survivors of adult cancers: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To provide evidence-based guidance on the optimum prevention and treatment approaches in the management of chemotherapy-induced peripheral neuropathies (CIPN) in adult cancer survivors.

METHODS

A systematic literature search identified relevant, randomized controlled trials (RCTs) for the treatment of CIPN. Primary outcomes included incidence and severity of neuropathy as measured by neurophysiologic changes, patient-reported outcomes, and quality of life.

RESULTS

A total of 48 RCTs met eligibility criteria and comprise the evidentiary basis for the recommendations. Trials tended to be small and heterogeneous, many with insufficient sample sizes to detect clinically important differences in outcomes. Primary outcomes varied across the trials, and in most cases, studies were not directly comparable because of different outcomes, measurements, and instruments used at different time points. The strength of the recommendations is based on the quality, amount, and consistency of the evidence and the balance between benefits and harms.

RECOMMENDATIONS

On the basis of the paucity of high-quality, consistent evidence, there are no agents recommended for the prevention of CIPN. With regard to the treatment of existing CIPN, the best available data support a moderate recommendation for treatment with duloxetine. Although the CIPN trials are inconclusive regarding tricyclic antidepressants (such as nortriptyline), gabapentin, and a compounded topical gel containing baclofen, amitriptyline HCL, and ketamine, these agents may be offered on the basis of data supporting their utility in other neuropathic pain conditions given the limited other CIPN treatment options. Further research on these agents is warranted.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic drugs used to treat many types of solid tumours 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 and safety of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related drugs.

SEARCH METHODS

On 4 March 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and CINAHL Plus for randomised trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related drugs among human patients.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs in which the participants received chemotherapy with cisplatin or related compounds, with a potential chemoprotectant (acetylcysteine, amifostine, adrenocorticotrophic hormone (ACTH), BNP7787, calcium and magnesium (Ca/Mg), diethyldithiocarbamate (DDTC), glutathione, Org 2766, oxcarbazepine, or vitamin E) compared to placebo, no treatment, or other treatments. We considered trials in which participants underwent evaluation zero to six months after completing chemotherapy using quantitative sensory testing (the primary outcome) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary outcomes).

DATA COLLECTION AND ANALYSIS

Two review authors assessed each study, extracted the data and reached consensus, according to standard Cochrane methodology.

MAIN RESULTS

As of 2013, the review includes 29 studies describing nine possible chemoprotective agents, as well as description of two published meta-analyses. Among these trials, there were sufficient data in some instances to combine the results from different studies, most often using data from secondary non-quantitative measures. Nine of the studies were newly included at this update. Few of the included studies were at a high risk of bias overall, although often there was too little information to make an assessment. At least two review authors performed a formal review of an additional 44 articles but we did not include them in the final review for a variety of reasons.Of seven eligible amifostine trials (743 participants in total), one used quantitative sensory testing (vibration perception threshold) and demonstrated a favourable 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. Furthermore the change measured was subclinical. None of the three eligible Ca/Mg trials (or four trials if a single retrospective study was included) described our primary outcome measures. The four Ca/Mg trials included a total of 886 participants. Of the seven eligible glutathione trials (387 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing but reported disparate results; meta-analyses of three of these trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. Similarly, none of the three eligible vitamin E trials (246 participants) reported quantitative sensory testing. The eligible single trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), oxcarbazepine (32 participants), and retinoic acid (92 participants) did not perform quantitative sensory testing. In all, this review includes data from 2906 participants. However, only seven trials reported data for the primary outcome measure of this review, (quantitative sensory testing) and only nine trials reported our objective secondary measure, nerve conduction test results. Additionally, methodological heterogeneity precluded pooling of the results in most cases. Nonetheless, a larger number of trials reported the results of secondary (non-quantitative and subjective) measures such as the National Cancer Institute Common Toxicity Criteria (NCI-CTC) for neuropathy (15 trials), and these results we pooled and reported as meta-analysis. Amifostine showed a significantly reduced risk of developing neurotoxicity NCI-CTC (or equivalent) ≥ 2 compared to placebo (RR 0.26, 95% CI 0.11 to 0.61). Glutathione was also efficacious with an RR of 0.29 (95% CI 0.10 to 0.85). In three vitamin E studies subjective measures not suitable for combination in meta analysis each favoured vitamin E. For other interventions the qualitative toxicity measures were either negative (N-acetyl cysteine, Ca/Mg, DDTC and retinoic acid) or not evaluated (oxcarbazepine and Org 2766).Adverse events were infrequent or not reported for most interventions. Amifostine was associated with transient hypotension in 8% to 62% of participants, retinoic acid with hypocalcaemia in 11%, and approximately 20% of participantss withdrew from treatment with DDTC because of toxicity.

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, oxcarbazepine, retinoic acid, or vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients, as determined using quantitative, objective measures of neuropathy. Amifostine, calcium and magnesium, glutathione, and vitamin E showed modest but promising (borderline statistically significant) results favouring their ability to reduce the neurotoxicity of cisplatin and related chemotherapies, as measured using secondary, non-quantitative and subjective measures such as the NCI-CTC neuropathy grading scale. Among these interventions, the efficacy of only vitamin E was evaluated using quantitative nerve conduction studies; the results were negative and did not support the positive findings based on the qualitative measures. In summary, the present studies are limited by the small number of participants receiving any particular agent, a lack of objective measures of neuropathy, and differing results among similar trials, which make it impossible to conclude that any of the neuroprotective agents tested prevent or limit the neurotoxicity of platinum drugs.

Phase III randomized, placebo-controlled, double-blind study of intravenous calcium and magnesium to prevent oxaliplatin-induced sensory neurotoxicity (N08CB/Alliance)

PURPOSE

Cumulative neurotoxicity is a prominent toxicity of oxaliplatin-based therapy. Intravenous calcium and magnesium have been extensively used to reduce oxaliplatin-induced neurotoxicity. This trial was designed to definitively test whether calcium/magnesium decreases oxaliplatin-related neurotoxicity.

PATIENTS AND METHODS

In all, 353 patients with colon cancer undergoing adjuvant therapy with FOLFOX (fluorouracil, leucovorin, and oxaliplatin) were randomly assigned to intravenous calcium/magnesium before and after oxaliplatin, a placebo before and after, or calcium/magnesium before and placebo after. The primary end point was cumulative neurotoxicity measured by the sensory scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy 20 tool.

RESULTS

There were no statistically significant neuropathy differences among the study arms as measured by the primary end point or additional measures of neuropathy, including clinician-determined measurement of the time to grade 2 neuropathy by using the National Cancer Institute Common Terminology Criteria for Adverse Events scale or an oxaliplatin-specific neuropathy scale. In addition, calcium/magnesium did not substantially decrease oxaliplatin-induced acute neuropathy.

CONCLUSION

This study does not support using calcium/magnesium to protect against oxaliplatin-induced neurotoxicity.

Phase I drug-interaction study of effects of calcium and magnesium infusions on oxaliplatin pharmacokinetics and acute neurotoxicity in colorectal cancer patients

BACKGROUND

Calcium and magnesium (Ca/Mg) infusions have been suggested as an effective intervention for preventing oxaliplatin-induced neurotoxicity, but the effects of Ca/Mg infusions on oxaliplatin pharmacokinetics, motor nerve hyperexcitability and acute neurotoxicity symptoms are unclear.

METHODS

In this double blind crossover study, colorectal cancer patients undergoing oxaliplatin-based chemotherapy were randomised to receive Ca/Mg (1g Ca Gluconate plus 1g MgSO4) on cycle 1 and placebo (vehicle alone) on cycle 2, or to receive the same treatments in the opposite sequence. Study endpoints included plasma pharmacokinetics of intact oxaliplatin and free platinum; electromyography (EMG) detection of abnormal spontaneous high-frequency motor unit action potential discharges; and patient-reported acute neurotoxicity symptoms and their preferred study treatment for reducing these symptoms.

RESULTS

Nineteen of 20 enrolled patients completed the study. Plasma pharmacokinetics of intact oxaliplatin and free platinum were similar when oxaliplatin was given with Ca/Mg or placebo (ratio of geometric means of AUC0-t with Ca/Mg or placebo: intact oxaliplatin, 0.95 (90% CI, 0.90 - 1.01); free platinum, 0.99 (90% CI, 0.94 - 1.05)). EMG motor nerve hyperexcitability scores were similar with Ca/Mg and placebo (mean difference in EMG score between Ca/Mg and placebo: -0.3 (95% CI, -2.2 - 1.6)). Patient-reported acute neurotoxicity symptoms were similar in frequency with Ca/Mg and placebo. For reducing neurotoxic symptoms, fewer patients preferred Ca/Mg than placebo or neither treatment (26% versus 74%; P<0.01).

CONCLUSIONS

Ca/Mg infusions do not alter the clinical pharmacokinetics of oxaliplatin and do not seem to reduce its acute neurotoxicity.

TRIAL REGISTRATION

Trial registration identifier ACTRN12611000738921.

Neurological Adverse Effects in Patients of Advanced Colorectal Carcinoma Treated with Different Schedules of FOLFOX

The study is designed to assess the frequency and severity of few dose limiting neurological adverse effects of four different schedules of FOLFOX. Patients with histologically confirmed advanced colorectal carcinoma (CRC) were included in the study. Toxicity was graded according to CTC v 2.0. The frequency of grade 3 and 4 adverse effects was comparatively assessed in each treatment arm. The difference in the pattern of toxicity between the treatment schedule was evaluated. The most frequent adverse symptom of neurological adverse effect was grade 1 paresthesia in the patients treated with FOLFOX4 schedule. Grade 4 peripheral neuropathy was reported in few patients of FOLFOX7 treatment arm. Frequency and onset of neurological adverse effects like paresthesia, dizziness, and hypoesthesia were significantly different (P < 0.05), whereas frequency and onset of peripheral neuropathy were highly significant (P < 0.01) in each treatment arm of FOLFOX. Peripheral neuropathy was associated with electrolyte imbalance and diabetes in few patients. Frequency of symptoms, for example, paresthesia, is associated with increased number of recurrent exposure to oxaliplatin (increased number of cycles) even at low doses (85 mg/m²), whereas severity of symptoms, for example, peripheral neuropathy, is associated with higher dose (130 mg/m²) after few treatment cycles.

Safety and efficacy of calcium and magnesium infusions in the chemoprevention of oxaliplatin-induced sensory neuropathy in gastrointestinal cancers

OBJECTIVE

To derive a more precise estimation on the safety and efficacy of calcium and magnesium (Ca and Mg) infusions in the prevention of oxaliplatin-induced sensory neuropathy.

METHODS

A total of 16 studies including 1765 individuals were involved in this meta-analysis. Odds ratio (OR) and its 95% confidence interval (CI) were calculated.

RESULTS

The difference in the incidence of oxaliplatin-induced neuropathy grade ≥ 1 was statistically significant between the Ca and Mg infusions treatment group and the untreated group (National Cancer Institute common toxicity criteria [NCI CTC]: OR 0.44, 95% CI 0.31-0.62, P = 0.000; oxaliplatin-specific scale [OSS]: OR 0.30, 95% CI 0.20-0.45, P = 0.000). Similar results were found in the incidences of oxaliplatin-induced neuropathy grade ≥ 2 (NCI CTC: OR 0.60, 95% CI 0.46-0.77, P = 0.000; OSS: OR 0.45, 95% CI 0.30-0.67, P = 0.000). However, we did not detect a trend of fewer oxaliplatin-induced neuropathy grade ≥ 3 incidences in the Ca and Mg infusions treatment group than the untreated group (NCI CTC: OR 0.67, 95% CI 0.44-1.01, P = 0.054; OSS: OR 0.66, 95% CI 0.34-1.29, P = 0.224). There was no difference in the response rate between the Ca and Mg treated group and the untreated group (OR 0.89, 95% CI 0.67-1.17, P = 0.391).

CONCLUSION

Ca and Mg infusions do not alter the efficacy of oxaliplatin-based chemotherapy in gastrointestinal cancers, which may be reasonable to add them to lessen the incidence of neuropathy.

Effects of calcium and magnesium on acute and chronic neurotoxicity caused by oxaliplatin: A meta-analysis

The primary toxicity of oxaliplatin is neurotoxicity. Calcium and magnesium (Ca/Mg) are reported to be beneficial in protecting against this adverse effect. However, the results obtained from clinical trials are not definitive. The aim of this study was to evaluate whether Ca/Mg alleviates the neurotoxicity of oxaliplatin by performing a meta-analysis of the literature involving available randomized controlled trials. Systematic searches for trials were undertaken from the Cochrane Library, MEDLINE, CENTRAL, Embase, CBMdisc and CNKI databases without language limitations. The primary outcome was severe chronic neurotoxicity and the secondary outcome was acute neurotoxicity. Four randomized double-blind trials met the search criteria. The odds ratio (OR) comparing Ca/Mg treatment with placebo was 0.44 (0.23–0.85, P=0.01) for severe chronic neurotoxicity of oxaliplatin (grade ≥2) and 0.41 (0.11–1.49, P=0.18) for acute neurotoxicity. In conclusion, Ca/Mg treatment does not reduce the incidence of acute neurotoxicity of oxaliplatin, but does reduce the incidence of severe chronic neurotoxicity (grade ≥2). No differences were observed in the outcomes of chemotherapy. Thus, Ca/Mg treatment is recommended for use as an adjunct with oxaliplatin.

Ca/Mg infusions for the prevention of oxaliplatin-related neurotoxicity in patients with colorectal cancer: a meta-analysis

BACKGROUND

Oxaliplatin-related neurotoxicity is the main limitation for its continuation in adjuvant and palliative chemotherapy for patients with colorectal cancer. The purpose of this meta-analysis was to determine the efficacy of calcium and magnesium (Ca/Mg) infusions in oxaliplatin-induced neurotoxicity.

METHODS

Two independent authors conducted database searches of the literature to find clinical-controlled trials analyzing Ca/Mg infusions in oxaliplatin-induced neurotoxicity. The keywords used to search were oxaliplatin, neurotoxicity, calcium, magnesium, neuropathy, and peripheral. Clinical studies that included at least one primary or secondary event were eligible for the analysis, where primary events were incidences of acute and cumulative neurotoxicity, and secondary events were the total doses and cycles of oxaliplatin, response rate (RR), overall survival (OS), and progression-free survival (PFS). Odds ratios (ORs) and weighted mean differences (MD) were analyzed using models of fixed and random effects.

RESULTS

This meta-analysis comprised four prospective randomized clinical trials and three retrospective clinical trials involving 1170 colorectal cancer patients, of which 802 received Ca/Mg infusions (Ca/Mg group) and 368 did not (control group). According to the National Cancer Institute-Common Terminology Criteria for Adverse Events, the incidence of grade 3 acute neurotoxicity in those who received Ca/Mg was significantly lower than that of the control group (OR=0.26; 95% confidence interval (CI), 0.11 to 0.62; P=0.0002). The total rate of cumulative neurotoxicity, and that of grade 3 in particular, was significantly lower in the Ca/Mg group than in the control group (OR=0.42; 95% CI 0.26-0.65; P=0.0001; OR=0.60; 95% CI 0.39-0.92; P=0.02, respectively). The differences in total doses and cycles of oxaliplatin were also significant between the Ca/Mg and control group (MD=246.73 mg/m2; 95% CI 3.01-490.45; P=0.05; MD=1.55; 95% CI 0.46-2.63; P=0.005, respectively). No significant differences were found in median PFS (MD=0.71 month; 95% CI -0.59-2.01; P=0.29), median OS (MD=0.10 month; 95% CI -0.41-0.61; P=0.70) or RRs (OR=0.82; 95% CI 0.61-1.10; P=0.18).

CONCLUSION

Ca/Mg infusions tend to decrease the incidence of oxaliplatin-induced acute and cumulative neurotoxicity and thus enhance patients' tolerance to oxaliplatin, without significantly altering the efficacy of chemotherapy.

Calcium and magnesium prophylaxis for oxaliplatin-related neurotoxicity: is it a trade-off between drug efficacy and toxicity?

Oxaliplatin-based chemotherapy regimens are the current standard treatment in the management of colorectal cancer. Neurotoxicity is the major cause of treatment delay, dose reduction, and cessation of oxaliplatin. Evidence regarding the role of calcium and magnesium prophylaxis to prevent oxaliplatin-related neurotoxicity is conflicting and further randomized data are needed to answer this question accurately. The purpose of this paper is to provide a critical overview of various studies that have been conducted so far to evaluate the preventative role of calcium and magnesium prophylaxis against oxaliplatin-related neurotoxicity.