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

Endothelial Glycocalyx in the Peripheral Capillaries is Injured Under Oxaliplatin-Induced Neuropathy

Oxaliplatin, a platinum-based anticancer drug, is associated with peripheral neuropathy (oxaliplatin-induced peripheral neuropathy, OIPN), which can lead to worsening of quality of life and treatment interruption. The endothelial glycocalyx, a fragile carbohydrate-rich layer covering the luminal surface of endothelial cells, acts as an endothelial gatekeeper and has been suggested to protect nerves, astrocytes, and other cells from toxins and substances released from the capillary vessels. Mechanisms underlying OIPN and the role of the glycocalyx remain unclear. This study aimed to define changes in the three-dimensional ultrastructure of capillary endothelial glycocalyx near nerve fibers in the hind paws of mice with OIPN. The mouse model of OPIN revealed disruption of the endothelial glycocalyx in the peripheral nerve compartment, accompanied by vascular permeability, edema, and damage to the peripheral nerves. To investigate the potential treatment interventions, nafamostat mesilate, a glycocalyx protective agent was used in tumor-bearing male mice. Nafamostat mesilate suppressed mechanical allodynia associated with neuropathy. It also prevented intra-epidermal nerve fiber loss and improved vascular permeability in the peripheral paws. The disruption of endothelial glycocalyx in the capillaries that lie within peripheral nerve bundles is a novel finding in OPIN. Furthermore, these findings point toward the potential of a new treatment strategy targeting endothelial glycocalyx to prevent vascular injury as an effective treatment of neuropathy as well as of many other diseases. PERSPECTIVE: OIPN damages the endothelial glycocalyx in the peripheral capillaries, increasing vascular permeability. In order to prevent OIPN, this work offers a novel therapy approach that targets endothelial glycocalyx.

Axonal degeneration in chemotherapy-induced peripheral neurotoxicity: clinical and experimental evidence

Multiple pathological mechanisms are involved in the development of chemotherapy-induced peripheral neurotoxicity (CIPN). Recent work has provided insights into the molecular mechanisms underlying chemotherapy-induced axonal degeneration. This review integrates evidence from preclinical and clinical work on the onset, progression and outcome of axonal degeneration in CIPN. We review likely triggers of axonal degeneration in CIPN and highlight evidence of molecular pathways involved in axonal degeneration and their relevance to CIPN, including SARM1-mediated axon degeneration pathway. We identify potential clinical markers of axonal dysfunction to provide early identification of toxicity as well as present potential treatment strategies to intervene in axonal degeneration pathways. A greater understanding of axonal degeneration processes in CIPN will provide important information regarding the development and progression of axonal dysfunction more broadly and will hopefully assist in the development of successful interventions for CIPN and other neurodegenerative disorders.

Cancer survivors post-chemotherapy exhibit unimpaired short-latency stretch reflexes in the proximal upper extremity

Oxaliplatin (OX) chemotherapy can lead to long-term sensorimotor impairments in cancer survivors. The impairments are often thought to be caused by OX-induced progressive degeneration of sensory afferents known as length-dependent dying-back sensory neuropathy. However, recent preclinical work has identified functional defects in the encoding of muscle proprioceptors and in motoneuron firing. These functional defects in the proprioceptive sensorimotor circuitry could readily impair muscle stretch reflexes, a fundamental building block of motor coordination. Given that muscle proprioceptors are distributed throughout skeletal muscle, defects in stretch reflexes could be widespread, including in the proximal region where dying-back sensory neuropathy is less prominent. All previous investigations on chemotherapy-related reflex changes focused on distal joints, leading to results that could be influenced by dying-back sensory neuropathy rather than more specific changes to sensorimotor circuitry. Our study extends this earlier work by quantifying stretch reflexes in the shoulder muscles in 16 cancer survivors and 16 healthy controls. Conduction studies of the sensory nerves in hand were completed to detect distal sensory neuropathy. We found no significant differences in the short-latency stretch reflexes (amplitude and latency) of the shoulder muscles between cancer survivors and healthy controls, contrasting with the expected differences based on the preclinical work. Our results may be linked to differences between the human and preclinical testing paradigms including, among many possibilities, differences in the tested limb or species. Determining the source of these differences will be important for developing a complete picture of how OX chemotherapy contributes to long-term sensorimotor impairments.NEW & NOTEWORTHY Our results showed that cancer survivors after oxaliplatin (OX) treatment exhibited stretch reflexes that were comparable with age-matched healthy individuals in the proximal upper limb. The lack of OX effect might be linked to differences between the clinical and preclinical testing paradigms. These findings refine our expectations derived from the preclinical study and guide future assessments of OX effects that may have been insensitive to our measurement techniques.

Oxaliplatin-induced peripheral neurotoxicity in colorectal cancer patients: mechanisms, pharmacokinetics and strategies

Oxaliplatin-based chemotherapy is a standard treatment approach for colorectal cancer (CRC). However, oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe dose-limiting clinical problem that might lead to treatment interruption. This neuropathy may be reversible after treatment discontinuation. Its complicated mechanisms are related to DNA damage, dysfunction of voltage-gated ion channels, neuroinflammation, transporters, oxidative stress, and mitochondrial dysfunction, etc. Several strategies have been proposed to diminish OIPN without compromising the efficacy of adjuvant therapy, namely, combination with chemoprotectants (such as glutathione, Ca/Mg, ibudilast, duloxetine, etc.), chronomodulated infusion, dose reduction, reintroduction of oxaliplatin and topical administration [hepatic arterial infusion chemotherapy (HAIC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and hyperthermic intraperitoneal chemotherapy (HIPEC)]. This article provides recent updates related to the potential mechanisms, therapeutic strategies in treatment of OIPN, and pharmacokinetics of several methods of oxaliplatin administration in clinical trials.

Fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy for gemcitabine-refractory advanced pancreatic cancer: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Fluoropyrimidine-based regimens have been investigated as the second line chemotherapy in patients with advanced pancreatic cancer refractory to gemcitabine. We conducted this systematic review and meta-analysis to evaluate the efficacy and safety profile of fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy in such patients.

METHODS

The databases of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ASCO Abstracts and ESMO Abstracts were systematically searched. Randomized controlled trials (RCTs) that compared fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy in patients with gemcitabine-refractory advanced pancreatic cancer were included. The primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), overall response rate (ORR) and serious toxicities. Statistical analyses were performed by using Review Manager 5.3. Egger's test was performed to assess the statistical evidence of publication bias by using stata 12.0.

RESULTS

A total of 1183 patients from six randomized controlled trials were included for this analysis. Fluoropyrimidine combination therapy increased ORR [RR 2.82 (1.83-4.33), p<0.00001] and PFS [HR 0.71 (0.62-0.82), p<0.00001], without significant heterogeneity. Fluoropyrimidine combination therapy improved OS [HR 0.82 (0.71-0.94), p = 0.006], with significant heterogeneity (I2 = 76%, p = 0.0009). The significant heterogeneity might have been caused by the different administration regimens and baseline characteristics. Peripheral neuropathy and diarrhea were more common in the regimens containing oxaliplatin and irinotecan, respectively. No publication bias was detected by Egger's tests.

CONCLUSIONS

Compared with fluoropyrimidine monotherapy, fluoropyrimidine combination therapy had a higher response rate and longer PFS in patients with gemcitabine-refractory advanced pancreatic cancer. Fluoropyrimidine combination therapy could be recommended in the second line setting. However, due to concerns about toxicities, the dose intensities of chemotherapy drugs should be carefully considered in patients with weakness.

Prognostic value of cutaneous reinnervation with GAP-43 in oxaliplatin-induced neuropathy

Background and purpose

Oxaliplatin-induced neuropathy (OIN) implies axonal damage of both small and large sensory nerve fibers. We aimed at comparing the neurophysiological changes occurred after treatment and the capability to recovery based on histological marker of re-innervation GAP-43.

Methods

48 patients with cancer were assessed before and after chemotherapy (at 3 months and 12 months if available). We recorded ulnar and sural sensory nerve action potentials (SNAP), determined quantitative sensory thresholds for warm and cold (WDT, CDT), pain thresholds and collected a distal biopsy of skin to assess the intra-epidermal nerve fiber density (IENFD) with PGP9.5 and GAP-43 markers (in a subgroup of 19 patients).

Results

Increased WDT and CDT as well as diminished IENFD at distal leg were already found in 30% of oncologic patients before treatment. After oxaliplatin, there was a significant increase in thermal thresholds in 52% of patients, and a decrease of SNAP amplitude in the sural nerve in 67% patients. IENFD was reduced in 47% and remained unchanged in 37% after oxiplatin. The density of GAP-43 + fibers and GAP-43/PGP 9.5 ratio was similar before and after treatment showing that cutaneous re-innervation is preserved despite no clinical recovery was observed after one year.

Conclusion

Non-selective axonal loss affects sensory fibers in OIN. However, the presence of intra-epidermal regenerative sprouts detected by GAP-43 may reduce the impact of neurotoxicity in the small fibers with long-term sequelae mostly on myelinated nerve endings. Pre-oxaliplatin GAP-43 failed to identify patients with higher risk of damage or worse recovery after treatment.

Downregulation of metallothionein-2 contributes to oxaliplatin-induced neuropathic pain

Background

We previously reported a correlation between small doses of oxaliplatin penetrating onto the spinal cord and acute pain after chemotherapy. Here, we propose that MT2 within the spinal dorsal horns participates in the development of oxaliplatin-induced neuropathic pain and may be a pharmacological target for the prevention and treatment of chemotherapy-induced peripheral neuropathy (CIPN).

Methods

The rat model of CIPN was established by 5 consecutive injections of oxaliplatin (0.4 mg/100 g/day). Genetic restoration of neuron-specific metallothionein-2 was implemented 21 days before oxaliplatin treatment, and also, genetic inhibition by metallothionein-2 siRNA was performed. Mechanical allodynia and locomotor activity were assayed. Cell-specific expression of metallothionein-2, the mRNA levels of pro-inflammatory cytokines, nuclear translocation of NF-κB, the protein levels of expression of IκB-α, and interaction between IκB-α and P65 were evaluated in the spinal dorsal horns. Also, in vitro interaction of sequentially deleted IκB-α promoter with metallothionein-2 was used to assess the signal transduction mechanism.

Results

We found that oxaliplatin induced downregulation of metallothionein-2 in rat spinal cord neurons. By contrast, genetic restoration of metallothionein-2 in the spinal dorsal horn neuron blocked and reversed neuropathic pain in oxaliplatin-treated rats of both sexes, whereas genetic inhibition of metallothionein-2 triggered neuropathic pain in normal rats. Overall locomotor activity was not impaired after the genetic alterations of metallothionein-2. At the molecular level, metallothionein-2 modulated oxaliplatin-induced neuroinflammation, activation of NF-κB, and inactive transcriptional expression of IκB-α promoter, and these processes could be blocked by genetic restoration of metallothionein-2 in the spinal dorsal horn neurons.

Conclusions

Metallothionein-2 is a potential target for the prevention and treatment of CIPN. A reduction of NF-κB activation and inflammatory responses by enhancing the transcription of IκB-α promoter is proposed in the mechanism.

Behavior and electrophysiology studies of the peripheral neuropathy induced by individual and co-administration of paclitaxel and oxaliplatin in rat

AIMS

Antitumor agents, as taxanes and platinum compounds, induce peripheral neuropathies which can hamper their use for cancer treatment. The study of chemotherapy-induced neuropathies in humans is difficult because of ethical reasons, differences among administration protocols and intrinsic characteristics of patients. The aim of the present study is to compare the neuropathic signs induced by individual or combined administration of paclitaxel and oxaliplatin.

MAIN METHODS

Oxaliplatin and paclitaxel were administered individually and combined to induce peripheral neuropathy in rats, sensory neuropathic signs were assessed in the hind limbs and orofacial area. The in vitro skin-saphenous nerve preparation was used to record the axonal activity of Aδ sensory neurons.

KEY FINDINGS

Animals treated with the combination developed mechanical allodynia in the paws and muscular hyperalgesia in the orofacial area, which was similar to that in animals treated with monotherapy, the latter also developed cold allodynia in the paws. Aδ-fibers of the rats treated with the combination were hyperexcited and presented hypersensitivity to pressure stimulation of the innervated skin, also similar to that recorded in the fibers of the animals treated with monotherapy.

SIGNIFICANCE

Our work objectively demonstrates that the combination of a platinum compound with a taxane does not worsen the development of sensorial neuropathies in rats, which is an interesting data to take into account when the combination of antitumor drugs is necessary. Co-administration of antitumor drugs is more effective in cancer treatment without increasing the risk of the disabling neuropathic side effects.

Clinical and biochemical markers in CIPN: A reappraisal

The increased survival of cancer patients has raised growing public health concern on associated long-term consequences of antineoplastic treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is a primarily sensory polyneuropathy, which may be accompanied by pain, autonomic disturbances, and motor deficit. About 70% of treated cancer patients might develop CIPN during or after the completion of chemotherapy, and in most of them such complication persists after six months from the treatment. The definition of the potential risk of development and resolution of CIPN according to a clinical and biochemical profile would be certainly fundamental to tailor chemotherapy regimen and dosage on individual susceptibility. In recent years, patient-reported and clinician-related tools along with quality of life instruments have been featured as primary outcomes in clinical setting and randomized trials. New studies on metabolomics markers are further pursuing accurate and easily accessible indicators of peripheral nerve damage. The aim of this review is to outline the strengths and pitfalls of current knowledge on CIPN, and to provide a framework for future potential developments of standardized protocols involving clinical and biochemical markers for CIPN assessment and monitoring.

Oxaliplatin rechallenge in metastatic colorectal cancer patients with clinically significant oxaliplatin-induced peripheral neurotoxicity

We investigated whether rechallenge with oxaliplatin (OXA) can worsen the pre-existing oxaliplatin-induced peripheral neurotoxicity (OXAIPN) in metastatic colorectal cancer (mCRC) patients. Patients previously treated with OXA, having clinically significant grade 1 or 2 OXAIPN were assessed, after receiving rechallenge with OXA, using the clinical version of the Total Neuropathy Score (TNSc). Peripheral neuropathy was assessed at the end of first OXA exposure and at completion of OXA rechallenge. The first line OXA-based chemotherapy was completed at least 9 months earlier (OXA-free interval). We studied 25 mCRC patients, 14 males and 11 females, with a median age of 63 (35-77) years. After their first exposure to OXA-based chemotherapy, 9 (36%) patients developed grade 1 OXAIPN and 16 patients grade 2 (64%) neurotoxicity. OXA reintroduction with a median of 10 (8-14) cycles led to grade 1 OXAIPN in two patients (8%), grade 2 in 19 patients (76%), and grade 3 neuropathy in 4 (16%) patients Worsening of pre-existing OXAIPN was documented in seven (28%) patients and was significantly associated with higher OXA delivered cumulative dose (P < .001). Median TNSc scores following treatment (10; range 4-18) were significantly increased (P < .001), when compared to the scores recorded at the end of first line treatment (8; range 2-12). Rechallenging OXA appears to relatively worsen the severity of existing OXAIPN. However, the majority of rechallenged patients developed a clinically significant (grade 2) OXAIPN, rather than treatment-emergent grade 3. As such, OXA rechallenge might be a feasible option in patients previously having OXAIPN.

Mesenchymal stem cells reduce the oxaliplatin-induced sensory neuropathy through the reestablishment of redox homeostasis in the spinal cord

AIMS

The present study was designed to investigate whether the antinociceptive effect of bone marrow-derived mesenchymal stem/stromal cells (MSC) during oxaliplatin (OXL)-induced sensory neuropathy is related to antioxidant properties.

MAIN METHODS

Male mice C57BL/6 were submitted to repeated intravenous administration of OXL (1 mg/kg, 9 administrations). After the establishment of sensory neuropathy, mice were treated with a single intravenous administration of MSC (1 × 10⁶), vehicle or gabapentin. Paw mechanical and thermal nociceptive thresholds were evaluated through von Frey filaments and cold plate test, respectively. Motor performance was evaluated in the rota-rod test. Gene expression profile, cytokine levels, and oxidative stress markers in the spinal cord were evaluated by real-time PCR, ELISA and biochemical assays, respectively.

KEY FINDINGS

OXL-treated mice presented behavioral signs of sensory neuropathy, such as mechanical allodynia and thermal hyperalgesia, which were completely reverted by a single administration of MSC. Repeated oral treatment with gabapentin (70 mg/kg) induced only transient antinociception. The IL-1β and TNF-α spinal levels did not differ between mice with or without sensory neuropathy. MSC increased the levels of anti-inflammatory cytokines, IL-10 and TGF-β, in the spinal cord of neuropathic mice, in addition to increasing the gene expression of antioxidant factors SOD and Nrf-2. Additionally, nitrite and MDA spinal levels were reduced by the MSC treatment.

SIGNIFICANCE

MSC induce reversion of sensory neuropathy induced by OXL possibly by activation of anti-inflammatory and antioxidant pathways, leading to reestablishment of redox homeostasis in the spinal cord.

Ibudilast for prevention of oxaliplatin-induced acute neurotoxicity: a pilot study assessing preliminary efficacy, tolerability and pharmacokinetic interactions in patients with metastatic gastrointestinal cancer

PURPOSE

This prospective, open-label, sequential 'before vs. after' pilot study was conducted to provide preliminary efficacy and tolerability data for ibudilast in the prevention of oxaliplatin-induced neurotoxicity in patients with metastatic upper gastrointestinal or colorectal cancer. Any potential impact of ibudilast on oxaliplatin and 5-fluorouracil pharmacokinetics was also explored.

METHODS

Participants were administered a chemotherapy cycle (FOLFOX or CapeOx), followed by a chemotherapy cycle with co-administration of ibudilast 30 mg b.i.d. p.o. Efficacy was assessed on Day 3 and end of cycle using the Oxaliplatin-Specific Neurotoxicity Scale (OSNS) and additional clinical/patient-reported neurotoxicity measures. A population pharmacokinetic approach was used to determine oxaliplatin and 5-fluorouracil pharmacokinetics with and without ibudilast.

RESULTS

Sixteen participants consented; 14 completed both chemotherapy cycles. Across all measures, the majority of participants experienced either an improvement or no worsening of neurotoxicity with ibudilast treatment. Based on OSNS assessments, acute neurotoxicity was unchanged in 12/14 participants and improved in 2/14 participants. The 90% confidence interval (CI) of the dose-normalised ratio of oxaliplatin AUC (90% CI 95.0-109%) and 5-fluorouracil AUC (90% CI 66.5-173%) indicated no significant impact of ibudilast on systemic exposure.

CONCLUSION

This pilot study indicated ibudilast co-administration may improve or stabilise oxaliplatin-induced neurotoxicity. Given the expected worsening of symptoms in patients with continued chemotherapy, this represents a signal of effect that warrants further investigation. Pharmacokinetic analysis indicates ibudilast has no significant effect on oxaliplatin pharmacokinetics, and is unlikely to influence pharmacokinetics of 5-fluorouracil.

CLINICAL TRIAL REGISTRATION

Trial registration number: UTN U1111-1209-0075 and ANZCTRN12618000232235 (registered 13/02/2018).

The preliminary effects of henna on chemotherapy-induced peripheral neuropathy in women receiving oxaliplatin-based treatment: A parallel-group, randomized, controlled pilot trial

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) may frequently occur in patients receiving oxaliplatin-based treatment. The aim of the present parallel-group, randomized, controlled pilot trial was to investigate the effect of henna on CIPN in women receiving oxaliplatin-based treatment.

METHOD

Sixty female patients receiving oxaliplatin-based treatment were randomly divided into two groups, i.e., one intervention group (n = 30) where henna was applied topically and one control group (n = 30) that received routine treatment and care. Women in the intervention group were provided a pack of henna prepared by the investigators following each treatment course (2nd, 3rd, and 4th courses) and were instructed to apply the henna on their palms, fingers, and soles. The chemotherapy-induced peripheral neuropathy assessment tool (CIPNAT) was completed by women subsequent to the 2nd (baseline), 3rd, and 4th courses of treatment.

RESULTS

The intragroup assessment performed for the intervention group revealed that the total CIPNAT score significantly declined in the intervention group (p < 0.05). The score changes by time in the intervention and control groups were in favour of the intervention group, and the effect size for group × time interaction was η² = 0.169. Similarly, regarding the symptoms intervention section of the tool, a positive change by time in the intervention group was observed, and the effect size concerning this change was large, i.e., η² = 0.284.

CONCLUSIONS

The present study results showed that henna application on hands and feet has a beneficial effect on peripheral neuropathy. Applying henna is a promising approach in CIPN management.

Real world, open label experience with lacosamide against acute painful oxaliplatin-induced peripheral neurotoxicity

We report the outcome of a pilot, open-label study that tested the potential of lacosamide (200 mg/bi.d) as an effective and safe symptomatic treatment against acute painful oxaliplatin-induced peripheral neurotoxicity (OXAIPN). Lacosamide was introduced in 18 colorectal cancer patients with evidence of clinically significant acute, painful OXAIPN after infusion of the third course (T1) of oxaliplatin-based chemotherapy (FOLFOX4) and was maintained until completion of all 12 courses (T4). The OXA-Neuropathy Questionnaire (OXA-NQ) was used to record the severity of acute OXAIPN; the PI-NRS estimated the severity of neuropathic pain, while the chronic OXAIPN was graded with TNSc. The EuroQOL (EQ-5D) instrument was also applied. The Patient Global Impression of Change (PGIC) scale measured the lacosamide-attributed perception of change. LCM-responders were considered those with ≥50% reduction in PI-NRS and OXA-NQ scores at T4, compared to T1. Patients experienced on T1 a median number of acute OXAIPN symptoms of 4 and had a median neuropathic pain severity score of 6, which was strongly related to lower quality of life, according to EQ-VAS (P < .001). At T4, 12 patients (66.7%) were classified as responders. A significant clinical improvement was documented in the severity of acute OXAIPN and neuropathic pain in relation to lacosamide (P < .001) at T4 compared to T1, which was associated with improved EQ-VAS scores (P < .001). Twelve patients scored PGIC ≥5 (lacosamide-attributed) at T4. There were no incidences of early drop-outs for safety reasons. Lacosamide appears to be an effective and well-tolerated symptomatic treatment against acute, painful OXAIPN.

Platinum-induced peripheral neurotoxicity: From pathogenesis to treatment

Platinum-induced peripheral neurotoxicity (PIPN) is a common side effect of platinum-based chemotherapy that may cause dose reduction and discontinuation, with oxaliplatin being more neurotoxic. PIPN includes acute neurotoxicity restricted to oxaliplatin, and chronic non-length-dependent sensory neuronopathy with positive and negative sensory symptoms and neuropathic pain in both upper and lower limbs. Chronic sensory axonal neuropathy manifesting as stocking-and-glove distribution is also frequent. Worsening of neuropathic symptoms after completing the last chemotherapy course may occur. Motor and autonomic involvement is uncommon. Ototoxicity is frequent in children and more commonly to cisplatin. Platinum-based compounds result in more prolonged neuropathic symptoms in comparison to other chemotherapy agents. Patient reported outcomes questionnaires, clinical evaluation and instrumental tools offer complementary information in PIPN. Electrodiagnostic features include diffusely reduced/abolished sensory action potentials, in keeping with a sensory neuronopathy. PIPN is dependent on cumulative dose but there is a large variability in its occurrence. The search for additional risk factors for PIPN has thus far yielded no consistent findings. There are currently no neuroprotective strategies to reduce the risk of PIPN, and symptomatic treatment is limited to duloxetine that was found effective in a single phase III intervention study. This review critically examines the pathogenesis, incidence, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of PIPN.

Impact of peripheral neuropathy induced by platinum in first-line chemotherapy on second-line chemotherapy with paclitaxel for advanced gastric cancer

BACKGROUND

Fluoropyrimidine plus platinum, followed by paclitaxel (PTX) plus ramucirumab is a recommended treatment strategy for advanced gastric cancer (AGC). We investigated how peripheral neuropathy (PN), induced by platinum in first-line chemotherapy, affected the tolerability of second-line chemotherapy with PTX (2nd-PTX).

METHODS

The subjects were AGC patients who received second-line chemotherapy with PTX (2nd-PTX) after the failure of platinum-based chemotherapy between March 2015 and June 2018. We retrospectively reviewed PN severity, and dose reduction and/or discontinuation due to PN during 2nd-PTX, and compared the cumulative incidence of grade 2 PN between the two groups according to first-line chemotherapy containing oxaliplatin (L-OHP) or cisplatin (CDDP).

RESULTS

The L-OHP and CDDP groups consisted of 50 patients each. PN severity before 2nd-PTX was grade 1/2 in 46/12% of patients in the L-OHP group, and 100/0% in the CDDP group. The worst grades of chemotherapy-induced PN during 2nd-PTX were grades 1/2/3 in 40/34/14% of patients in the L-OHP group, and 36/18/0% in the CDDP group. Median time to grade 2 PN after starting second-PTX was 2.5 months in the L-OHP group and 8.6 months in the CDDP group (hazard ratio 3.34, p = 0.002). The frequencies of a PN-related dose reduction and/or discontinuation of PTX were 18% in the L-OHP group and 8% in the CDDP group (p = 0.234).

CONCLUSIONS

The severity of PN and tolerability of 2nd-PTX may be affected by first-line chemotherapy with L-OHP or CDDP for AGC.

Effect of Aromatherapy Massage on Chemotherapy-Induced Peripheral Neuropathic Pain and Fatigue in Patients Receiving Oxaliplatin: An Open Label Quasi-Randomized Controlled Pilot Study

BACKGROUND

Patients receiving oxaliplatin may experience peripheral neuropathic pain and fatigue. Aromatherapy massage, a nonpharmacological method, may help to control these symptoms.

OBJECTIVE

The aim of this open-label, parallel-group, quasi-randomized controlled pilot study was to investigate the effect of aromatherapy massage on chemotherapy-induced peripheral neuropathic pain and fatigue in patients receiving oxaliplatin.

METHODS

Stratified randomization was used to allocate 46 patients to 2 groups: intervention (n = 22) and control (n = 24). Between week 1 and week 6, participants in the intervention group (IG) received aromatherapy massage 3 times a week. There was no intervention in weeks 7 and 8. The control group (CG) received routine care. Neuropathic pain was identified using the Douleur Neuropathique 4 Questions; severity of painful paresthesia was assessed with the numerical rating scale; fatigue severity was identified with the Piper Fatigue Scale.

RESULTS

At week 6, the rate of neuropathic pain was significantly lower in the IG, when compared with the CG. The severity of painful paresthesia based on numerical rating scale in the IG was significantly lower than that in the CG at weeks 2, 4, and 6. At week 8, fatigue severity in the IG was significantly lower when compared with CG (P < .05).

CONCLUSION

Aromatherapy massage may be useful in the management of chemotherapy-induced peripheral neuropathic pain and fatigue.

IMPLICATIONS FOR PRACTICE

This pilot study suggests that aromatherapy massage may be useful to relieve neuropathic pain and fatigue. However, there is a need for further clinical trials to validate the results of this study.

Protective effect of N-acetylcysteine on oxaliplatin-induced neurotoxicity in patients with colorectal and gastric cancers: A randomized, double blind, placebo-controlled, clinical trial

PURPOSE

Neuropathy is one of the most prevalent and dose-limiting side effects of platinum chemotherapeutic agents. N-acetylcysteine is an antioxidant thiol which is able to increase whole blood concentration of glutathione, which may be protective against chemotherapy-induced neuropathy. The aim of this study was to evaluate the effect of N-acetylcysteine on neurotoxicity induced by oxaliplatin in patients with gastric or colorectal cancers.

METHODS

During this randomized, double-blinded, placebo-controlled clinical trial, the preventive effect of N-acetylcysteine effervescent tablets was assessed in comparison with placebo, on neuropathy occurrence. Thirty-two patients with colorectal or gastric cancer randomly received N-acetylcysteine (two 600 mg tablets) or placebo tablets 1 h before receiving oxaliplatin in dose in XELOX (oxaliplatin and capecitabine regimen) for eight courses of chemotherapy. Neuropathy severity was assessed after eight courses of chemotherapy based on National Cancer Institute Common Terminology for Adverse Events (NCI-CTCAE) criteria neuropathy grading scale and also sensory and motor electrophysiological assessment was performed by a neurologist.

RESULTS

The NCI-CTCAE scale grade of patients in intervention group was significantly lower than placebo group after eight course of oxaliplatin (P = 0.01); however, the sensory electrophysiological assessment result was not significantly different (P = 0.501). No patient in both group had motor electrophysiological changes.

CONCLUSION

The results of this study showed that N-acetylcysteine could reduce the incidence of the neuropathy induced by oxaliplatin and delay its occurrence in patients with gastric or colorectal cancers.

Liability of the voltage-gated potassium channel KCNN3 repeat polymorphism to acute oxaliplatin-induced peripheral neurotoxicity

Thus far, there are conflicting results on the causal role of K+ channels in the pathogenesis of acute oxaliplatin-induced peripheral neurotoxicity (OXAIPN). As such, we tested the hypothesis that the voltage-gated K+ channel KCNN3 repeat polymorphism confers liability to acute OXAIPN. DNA from 151 oxaliplatin-treated patients for colorectal cancer was extracted and genotyped. The incidence of acute OXIPN was measured by the OXA-neuropathy questionnaire, while the severity of acute OXAIPN was scored basing on the number of symptoms reported by the patients at each clinical assessment. The increased number of acute symptoms was considered as being suggestive of an increased severity of acute OXAIPN. A total of 130/151 (86.1%) patients developed any grade of acute OXAIPN. Grade I acute neurotoxicity was revealed in 43 (28.5%) patients; grade II in 34 (22.5%); and grade III in 53 (53.1%) patients. Genotyping revealed alleles carrying 11 to 20 CAG repeats. The majority of patients were heterozygous (131; 89.4%). The most common numbers of CAG repeats were 15 (n = 46), 16 (n = 53), and 17 (n = 95). Patients carrying alleles with either 15 to 17 CAG repeats (P = .601) did not experience a higher incidence of grade III (treatment-emergent) acute OXAIPN. Likewise, no increased incidence of acute treatment-emergent OXAIPN was noted in heterozygous patients carrying either two short alleles (<19 CAG repeats) or one short and one long (≥19 CAG repeats) allele (P = .701). Our results do not support a causal relationship between the KCNN3CAG repeat polymorphism and acute OXΑIPN.

Clinical and preclinical perspectives on Chemotherapy-Induced Peripheral Neuropathy (CIPN): a narrative review

This review provides an update on the current clinical and preclinical understanding of chemotherapy induced peripheral neuropathy (CIPN). The overview of the clinical syndrome includes a review of its assessment, diagnosis and treatment. CIPN is caused by several widely-used chemotherapeutics including paclitaxel, oxaliplatin, bortezomib. Severe CIPN may require dose reduction, or cessation, of chemotherapy, impacting on patient survival. While CIPN often resolves after chemotherapy, around 30% of patients will have persistent problems, impacting on function and quality of life. Early assessment and diagnosis is important, and we discuss tools developed for this purpose. There are no effective strategies to prevent CIPN, with limited evidence of effective drugs for treating established CIPN. Duloxetine has moderate evidence, with extrapolation from other neuropathic pain states generally being used to direct treatment options for CIPN. The preclinical perspective includes a discussion on the development of clinically-relevant rodent models of CIPN and some of the potentially modifiable mechanisms that have been identified using these models. We focus on the role of mitochondrial dysfunction, oxidative stress, immune cells and changes in ion channels from summary of the latest literature in these areas. Many causal mechanisms of CIPN occur simultaneously and/or can reinforce each other. Thus, combination therapies may well be required for most effective management. More effective treatment of CIPN will require closer links between oncology and pain management clinical teams to ensure CIPN patients are effectively monitored. Furthermore, continued close collaboration between clinical and preclinical research will facilitate the development of novel treatments for CIPN.

Chemokine CCL2 and its receptor CCR2 in the dorsal root ganglion contribute to oxaliplatin-induced mechanical hypersensitivity

Activation of innate immune mechanisms within the dorsal root ganglion and spinal dorsal horn has been shown to play a key role in the development of neuropathic pain including paclitaxel-related chemotherapy-induced peripheral neuropathy (CIPN). Here, we tested whether similar mechanisms are generalizable to oxaliplatin-induced CIPN. After a single intraperitoneal injection of 3 mg/kg oxaliplatin, mechanical withdrawal threshold and the expression of C-C chemokine ligand 2 (CCL2) and its receptor, CCR2, in the dorsal root ganglion were measured by behavioral testing and immunohistochemical staining, respectively. Mechanical responsiveness increased from the first day after oxaliplatin injection and persisted until day 15, the last day of this experiment. Immunohistochemical showed that the expression of CCL2/CCR2 started to increase by 4 hours after oxaliplatin treatment, was significantly increased at day 4, and then both signals became normalized by day 15. Cotreatment with intrathecal anti-CCL2 antibodies prevented the development of oxaliplatin-induced mechanical hyperresponsiveness, and transiently reversed established hyperalgesia when given 1 week after chemotherapy. This is the first study to demonstrate CCL2/CCR2 signaling in a model of oxaliplatin-related CIPN; and it further shows that blocking of this signal can attenuate the development of oxaliplatin-induced mechanical hyperalgesia. Activation of innate immune mechanisms may therefore be a generalized basis for CIPN irrespective of the specific class of agent.

First-in-human phase I study of the microtubule inhibitor plocabulin in patients with advanced solid tumors

Background Plocabulin (PM060184) is a novel marine-derived microtubule inhibitor that acts as an antitumor agent. This first-in-human study evaluated dose-limiting toxicities (DLT) to define the maximum tolerated dose (MTD) and phase II recommended dose (RD) of plocabulin given as a 10-min infusion on Day (D) 1, D8 and D15 every four weeks. Patients and methods Forty-four patients with advanced solid tumors received plocabulin following an accelerated titration design. Results Plocabulin was escalated from 1.3 mg/m² to 14.5 mg/m², which was defined as the MTD. No RD was confirmed, because frequent dose delays and omissions resulted in low relative dose intensity (66%) at the 12.0 mg/m² expansion cohort. The main DLT was grade 3 peripheral sensory neuropathy (PSN); other DLTs were grade 4 tumor lysis syndrome, grade 4 cardiac failure and grade 3 myalgia. Toxicities were mainly mild to moderate, and included abdominal pain, myalgia, fatigue, nausea, and vomiting. Myelosuppression was transient and manageable. Plocabulin had a half-life of ~4 h and a wide diffusion to peripheral tissues. Antitumor response was observed in cervix carcinoma and heavily pretreated metastatic non-small cell lung cancer patients, and disease stabilization (≥3 months) in patients with colorectal, thymic, gastrointestinal stromal and breast tumors, among others. The clinical benefit rate was 33%. Conclusion The main DLT of plocabulin was PSN, as anticipated for a tubulin-binding agent. Since encouraging antitumor activity was observed, efforts to improve toxicity and to find the RD were planned in other trials evaluating D1&D8 and D1-D3 plus D15-D17 schedules.

Analysis of reduced-dose administration of oxaliplatin as adjuvant FOLFOX chemotherapy for colorectal cancer

Purpose

An oxaliplatin-based regimen is the most common adjuvant chemotherapy for patients with stage II/III colorectal cancer, but many patients experience dose reduction or early termination of chemotherapy due to side effects. We conducted this study to verify the range of reduction with oncologic safety.

Methods

Patients with stage II/III colorectal cancer who received adjuvant FOLFOX chemotherapy were enrolled in this study. The total amount of oxaliplatin administered per patient was calculated as a percentile based on 12 cycles of full-dose FOLFOX as a standard dose. The cutoff values showing significant differences in survival were calculated, and the clinicopathologic outcomes of patient groups classified by the value were compared.

Results

Among a total of 611 patients, there were 107 stage II patients, and 504 stage III patients. At 60% of the standard dose of oxaliplatin, the patients in the dose reduction group were older (62 years vs. 58 years, P = 0.003), had lower body mass index (BMI) (23.1 kg/m²vs. 24.0 kg/m², P = 0.005), and were more exposed to neoadjuvant treatment (18.0% vs. 9.1%, P = 0.003) in comparison to the standard group. At 60% of the standard dose, there were no significant differences in 5-year disease-free survival (DFS) and overall survival (OS) between the 2 groups (5-year DFS: 73.5% vs. 74.2%, P = 0.519; 5-year OS: 71.9% vs. 81.5%, P = 0.256, respectively).

Conclusion

Patients with old age, low BMI, and more frequent exposure to neoadjuvant treatment tended to show lower compliance with chemotherapy. More than 60% dose should be administered to patients with stage II/III colorectal cancer as adjuvant chemotherapy to achieve acceptable oncologic outcomes.

Reflexology in the management of chemotherapy induced peripheral neuropathy: A pilot randomized controlled trial

PURPOSE

The current experimental study aimed to evaluate the effectiveness of reflexology on the management of symptoms and functions of chemotherapy-induced peripheral neuropathy (CIPN) in cancer patients.

METHOD

This study was conducted as a randomized controlled trial in 60 patients (30 experimental and 30 control patients) who had chemotherapy-induced Grade II-IV peripheral neuropathy complaints from July 2013 to November 2015. Data were collected using the patient identification form, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy (EORTC-CIPN-20) form, and BPI (used for related chemotherapy-induced peripheral neuropathy symptoms).

RESULTS

The majority of the patients were being treated for gastrointestinal or breast cancer and were primarily receiving Eloxatine- or taxane-based treatment. It was found that reflexology applications did not lead to differences in either group in terms of peripheral neuropathy severity and incidence (p > 0.05) and only led to improvement in sensory functions in the experimental group (p < 0.05).

CONCLUSIONS

It was determined that reflexology is not an effective method in the management of patients' activity levels, walking ability etc. and motor, autonomic functions related CIPN, but reflexology is effective method in the management of patients' sensory functions related CIPN. Key Words: Peripheral neuropathy, reflexology, chemotherapy, EORTC QLQ-CIPN-20, BPI.

Neuroprotective effects and UPLC-Q-TOF/MS-based active components identification of external applied a novel Wen-Luo-Tong microemulsion

Chemotherapy induced neuropathy causes excruciating pain to cancer patients. Wen-Luo-Tong (WLT), a traditional Chinese medicinal compound, has been used to alleviate anti-cancer drug such as oxaliplatin-induced neuropathic pain for many years. However, the current route of administration of WLT is inconvenient and the active ingredients and mechanism of action of WLT are still unclear. To address these issues, we developed a novel formulation of WLT (W/O microemulsion) for the ease of application. New ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) methods were employed for analysis of the ingredients. We identified seven ingredients that penetrated through the skin into the Franz cell receptor solution and four of those ingredients were retained in skin tissue when WLT microemulsion was applied. We tested the microemulsion formulation on an oxaliplatin-induced neuropathy rat model and showed that this formulation significantly decreased oxaliplatin-induced mechanical hyperalgesia responses. Schwann cells (SCs) viability experiment in vitro was studied to test the protective effect of the identified seven ingredients. The result showed that Hydroxysafflor Yellow A, icariin, epimedin B and 4-dihydroxybenzoic acid significantly increased the viability of SCs after injured by Oxaliplatin. Our report presents the first novel formulation of WLT with neuroprotective effect and ease of use, which has potential for clinical applications.

Neurophysiological and clinical outcomes in chemotherapy-induced neuropathy in cancer

Chemotherapy induced peripheral neuropathy (CIPN) is a significant toxicity of cancer treatment, with the potential to affect long-term function and quality of life in cancer survivors. There remains a lack of consensus around optimal assessment techniques. While current approaches to CIPN assessment are focused on clinical grading scales, it is becoming increasingly evident that a more comprehensive multimodal assessment package is necessary to accurately characterise the impact of CIPN as well as gauge the utility of neuroprotective mechanisms. Neurophysiological techniques provide objective biomarkers and may enable early detection of toxicity while patient reported outcomes are necessary to determine the significance of symptoms to individual patients. In addition to providing an objective assessment, clinical neurophysiological techniques provide important insights into the contributory pathophysiological mechanisms of CIPN with different chemotherapy agents. There is a paucity of implementation of these techniques in the clinical trial setting. The present Review aims to facilitate the use of neurophysiological studies as part of comprehensive assessment packages for the monitoring of CIPN by summarising current understanding of neurophysiological changes that underlie the development of neuropathy, clinical presentations and patient reported outcomes as well as advantages and limitations of current techniques for the neurophysiological assessment of CIPN.

Prevalence of Oxaliplatin-induced Chronic Neuropathy and Influencing Factors in Patients with Colorectal Cancer in Iran

BACKGROUND

The chemotherapeutic agent oxaliplatin can cause acute and chronic forms of peripheral neuropathy. The aim of this study was to evaluate the incidence of chronic neuropathy and its risk factors in colorectal cancer (CRC) patients treated with FOLFOX or XELOX regimens in the Oncology Ward of Hazrat-e-Rasoul Hospital in Tehran.

MATERIALS AND METHODS

A total of 130 patients with CRC were entered into our study, aged over 18 years, without history of receiving other neurotoxic agents or other predisposing factors such as diabetes or neurologic diseases and kidney and liver dysfunction. For the FOLFOX regimen, patients received oxaliplatin, 85 mg/m2, every 2 weeks for 12 courses and with the XELOX regimen, oxaliplatin was 130 mg/m(2), every 3 weeks for 8 courses. Based on Common Toxicity Criteria (CTC or NCI-CTC v.3), the patients were divided into 5 groups (grades) based on the severity of their symptoms.

RESULTS

Fifty-seven patients (43.8%) were male and 73(56.2%) female. Some 19 patients (14.7%) had BMI<20, 97(74.6%) were between 20-25 and 14 (10.8%) ≥ 25. In 105 patients (80.7%) neuropathy was found. There was significant correlation between BMI, hypomagnesaemia and especially, severity of anemia in patients with neuropathy compared to those without.

CONCLUSIONS

Oxaliplatin regimens can induce chronic neuropathy in CRC patients, with anemia, high BMI and hypomagnesaemia as risk factors that can predispose to this kind of neurotoxicity.

The effect of n-3 polyunsaturated fatty acids on incidence and severity of oxaliplatin induced peripheral neuropathy: a randomized controlled trial

BACKGROUND

Oxaliplatin induced peripheral neurotoxicity (OXIPN) is the major dose-limiting and long-lasting side effect of oxaliplatin. N-3 PUFAs have neuroprotective property via their effects on voltage-gated ion channels and by reducing the production of proinflammatory cytokines that causes neuropathy. This study was a randomized double blind placebo controlled trial to find the possible advantages of n-3 PUFAs for preventing and reducing the severity of OXIPN in patients with colon cancer.

METHODS

Eligible patients with colon cancer randomly allocated to take n-3 PUFAs pearls, 640 mg t.i.d during chemotherapy with oxaliplatin and one month after the cessation of the treatment or placebo. All patients were evaluated for incidence and severity of OXIPN based on "reduced Total Neuropathy Score" in which clinical and electrophysiological assessments were included.

RESULTS

Seventeen patients (47 %) of the n-3 PUFA supplemented group (n = 36) did not develop PN while it was 11 %(4 patients) in the placebo group (n = 35). There was a significant difference in PN incidence (OR = 0.14, .95 % CI = (0.04 to 0.49), p = 0.002). The difference of OXIPN severity was significant between the two study groups (B = -1.61, 0.95 % CI = (-2.59 to -0.62), p = 0.001).

CONCLUSIONS

N-3 PUFAs may have neuroprotective effect for reducing the incidence and severity of OXIPN. Finding an effective prophylactic or symptomatic therapy for OXIPN would significantly improve the patients' quality of life.

TRIAL REGISTRATION

IRCT201112158397N2.

Chemotherapy-induced painful neuropathy: pain-like behaviours in rodent models and their response to commonly used analgesics

PURPOSE OF REVIEW

Chemotherapy-induced painful neuropathy (CIPN) is a major dose-limiting side-effect of several widely used chemotherapeutics. Rodent models of CIPN have been developed using a range of dosing regimens to reproduce pain-like behaviours akin to patient-reported symptoms. This review aims to connect recent evidence-based suggestions for clinical treatment to preclinical data.

RECENT FINDINGS

We will discuss CIPN models evoked by systemic administration of taxanes (paclitaxel and docetaxel), platinum-based agents (oxaliplatin and cisplatin), and the proteasome-inhibitor - bortezomib. We present an overview of dosing regimens to produce CIPN models and their phenotype of pain-like behaviours. In addition, we will discuss how potential, clinically available treatments affect pain-like behaviours in these rodent models, relating those effects to clinical trial data wherever possible. We have focussed on antidepressants, opioids, and gabapentinoids given their broad usage.

SUMMARY

The review outlines the latest description of the most-relevant rodent models of CIPN enabling comparison between chemotherapeutics, dosing regimen, rodent strain, and sex. Preclinical data support many of the recent suggestions for clinical management of established CIPN and provides evidence for potential treatments warranting clinical investigation. Continued research using rodent CIPN models will provide much needed understanding of the causal mechanisms of CIPN, leading to new treatments for this major clinical problem.

Long-term course of oxaliplatin-induced polyneuropathy: a prospective 2-year follow-up study

This prospective study sought to identify the potential reversibility of oxaliplatin-induced peripheral neuropathy (OXAIPN) by following-up its long-term course 2 years after discontinuation of oxaliplatin (OXA)-based chemotherapy. Participants were 91 colorectal cancer patients treated with OXA-based chemotherapy. Neurological assessment, clinical Total Neuropathy Score© (TNSc©) and nerve conduction studies were performed at baseline (T0), the end of chemotherapy (T1) and 2 years (T2) after discontinuation of chemotherapy. A total of 73 of 91 (80%) patients experienced OXAIPN at T1. At a median follow-up of 25 months, persistence of chronic OXAIPN was present in 61 of 73 patients (84%) and complete resolution was present in 12 patients (17%). Longitudinal comparison of TNSc© values between T1 and T2 revealed that the overall severity of OXAIPN in those 61 patients significantly decreased over time. Median TNSc© values were nine (range: 2-15) at T1 vs. four (range: 2-12) at T2 (P < 0.001). Likewise, sensory nerve conduction measures at T2 significantly improved in all sensory nerves tested, compared with T1. Severity of OXAIPN at T2 was significantly associated (P < 0.001) with high severity of OXAIPN at T1. In conclusion, persistence of OXAIPN beyond 2 years after finishing chemotherapy is common. Clinical and neurophysiological improvement is observed, although recovery is often incomplete.

Mechanisms involved in the development of chemotherapy-induced neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and painful condition seen in patients undergoing treatment with common agents such as vincristine, paclitaxel, oxaliplatin and bortezomib. The mechanisms of this condition are diverse, and include an array of molecular and cellular contributions. Current research implicates genetic predispositions to this condition, which then may influence cellular responses to chemotherapy. Processes found to be influenced during CIPN include increased expression of inflammatory mediators, primarily cytokines, which can create cascading effects in neurons and glia. Changes in ion channels and neurotransmission, as well as changes in intracellular signaling and structures have been implicated in CIPN. This review explores these issues and suggests considerations for future research.

Updates on Oxaliplatin-Induced Peripheral Neurotoxicity (OXAIPN)

Oxaliplatin-induced peripheral neuropathy (OXAIPN) is of great clinical interest as it ranks among the most common dose limiting toxicities of oxaliplatin (OXA) administration with an obvious impact on the outcome of cancer patients. In addition, OXAIPN has a detrimental effect on the quality of life of cancer patients because it can be long lasting or even permanent. It has a unique spectrum of clinical presentation, being manifested with two distinct syndromes: the acute neurotoxicity that appears soon after OXA administration and is usually transient, and the chronic cumulative syndrome that resembles the characteristics of all platinum compounds. Despite advances in research in relation to the elucidation of the true OXAIPN pathogenesis, characteristics and management, there are still several open issues to be addressed. One of the most important open issues is to determine reliable biomarkers to allow prompt identification of patients at high risk to develop OXAIPN and towards this view well designed genome wide analyses are warranted to adequately address this gap in knowledge. Recent updates are provided in this article in relation to the pathogenesis, clinical characteristics, pharmacogenetics and management of OXAIPN.

Oxaliplatin-Induced Peripheral Neuropathy via TRPA1 Stimulation in Mice Dorsal Root Ganglion Is Correlated with Aluminum Accumulation

Oxaliplatin is a platinum-based anticancer drug used to treat metastatic colorectal, breast, and lung cancers. While oxaliplatin kills cancer cells effectively, it exhibits several side effects of varying severity. Neuropathic pain is commonly experienced during treatment with oxaliplatin. Patients describe symptoms of paresthesias or dysesthesias that are triggered by cold (acute neuropathy), or as abnormal sensory or motor function (chronic neuropathy). In particular, we found that aluminum levels were relatively high in some cancer patients suffering from neuropathic pain based on clinical observations. Based on these findings, we hypothesized that aluminum accumulation in the dorsal root ganglion (DRG) in the course of oxaliplatin treatment exacerbates neuropathic pain. In mice injected with oxaliplatin (three cycles of 3 mg/kg i.p. daily for 5 days, followed by 5 days of rest), we detected cold allodynia using the acetone test, but not heat hyperalgesia using a hot plate. However, co-treatment with aluminum chloride (AlCl_3∙6H₂O; 7 mg/kg i.p. for 14 days: equivalent 0.78 mg/kg of elemental Al) and oxaliplatin (1 cycle of 3 mg/kg i.p. daily for 5 days, followed by 5 days of rest) synergistically induced cold allodynia as well as increased TRPAl mRNA and protein expression. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis showed a significant increase in aluminum concentrations in the DRG of mice treated with aluminum chloride and oxaliplatin compared to aluminum chloride alone. Similarly, in a mouse induced-tumor model, aluminum concentrations were increased in DRG tissue and tumor cells after oxaliplatin treatment. Taken together, these findings suggest that aluminum accumulation in the DRG may exacerbate neuropathic pain in oxaliplatin-treated mice.

Randomised phase II trial of S-1 plus oxaliplatin vs S-1 in patients with gemcitabine-refractory pancreatic cancer

Background:

This randomised, open-label, multicenter phase II study compared progression-free survival (PFS) of S-1 plus oxaliplatin (SOX) with that of S-1 alone in patients with gemcitabine-refractory pancreatic cancer.

Methods:

Patients with confirmed progressive disease following the first-line treatment with a gemcitabine-based regimen were randomised to receive either S-1 (80/100/120 mg day⁻¹ based on body surface area (BSA), orally, days 1–28, every 6 weeks) or SOX (S-1 80/100/120 mg day⁻¹ based on BSA, orally, days 1–14, plus oxaliplatin 100 mg m⁻², intravenously, day 1, every 3 weeks). The primary end point was PFS.

Results:

Between January 2009 and July 2010, 271 patients were randomly allocated to either S-1 (n=135) or SOX (n=136). Median PFS for S-1 and SOX were 2.8 and 3.0 months, respectively (hazard ratio (HR)=0.84; 95% confidence interval (CI), 0.65–1.08; stratified log-rank test P=0.18). Median overall survival (OS) was 6.9 vs 7.4 months (HR=1.03; 95% CI, 0.79–1.34; stratified log-rank test P=0.82). The response rate (RR) was 11.5% vs 20.9% (P=0.04). The major grade 3/4 toxicities (S-1 and SOX) were neutropenia (11.4% and 8.1%), thrombocytopenia (4.5% and 10.3%) and anorexia (12.9% and 14.7%).

Conclusions:

Although SOX showed an advantage in RR, it provided no significant improvement in PFS or OS compared with S-1 alone.

Comparison of operant escape and reflex tests of nociceptive sensitivity

Testing of reflexes such as flexion/withdrawal or licking/guarding is well established as the standard for evaluating nociceptive sensitivity and its modulation in preclinical investigations of laboratory animals. Concerns about this approach have been dismissed for practical reasons - reflex testing requires no training of the animals; it is simple to instrument; and responses are characterized by observers as latencies or thresholds for evocation. In order to evaluate this method, the present review summarizes a series of experiments in which reflex and operant escape responding are compared in normal animals and following surgical models of neuropathic pain or pharmacological intervention for pain. Particular attention is paid to relationships between reflex and escape responding and information on the pain sensitivity of normal human subjects or patients with pain. Numerous disparities between results for reflex and operant escape measures are described, but the results of operant testing are consistent with evidence from humans. Objective reasons are given for experimenters to choose between these and other methods of evaluating the nociceptive sensitivity of laboratory animals.

The contribution of Gi/o protein to opioid antinociception in an oxaliplatin-induced neuropathy rat model

Oxaliplatin is a chemotherapeutic agent that induces chronic refractory neuropathy. To determine whether opioids effectively relieve this chronic neuropathy, we investigated the efficacies of morphine, oxycodone, and fentanyl, and the mechanisms underlying opioid antinociception, in oxaliplatin-induced neuropathy in rats. Rats exhibited significant mechanical allodynia following 2 weeks of chronic oxaliplatin administration. Within the range of doses that did not induce sedation and/or muscle rigidity, morphine (3 mg/kg, subcutaneously, s.c.) and oxycodone (0.3-0.56 mg/kg, s.c.) completely reversed oxaliplatin-induced mechanical allodynia, whereas fentanyl (0.017-0.03 mg/kg, s.c.) showed partial antinociception. The antinociception of the optimal doses of morphine and oxycodone were completely inhibited by pertussis toxin (PTX; 0.5 μg/rat, i.c.v.), a Gi/o protein inhibitor, while the partial effect of fentanyl was not affected in the oxaliplatin model. In the [(35)S]-GTPγS binding assay, activation of μ-opioid receptor by fentanyl, but not by morphine or oxycodone, in the mediodorsal thalamus was significantly reduced in oxaliplatin-treated rats. These results indicate that the lower antinociceptive potency of fentanyl in the oxaliplatin model might in part result from the loss of PTX-sensitive Gi/o protein activation, and the degree of Gi/o protein activation might be related to the potency of antinociception by opioids in this model.

Incidence, prevalence, and predictors of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling pain condition resulting from chemotherapy for cancer. Severe acute CIPN may require chemotherapy dose reduction or cessation. There is no effective CIPN prevention strategy; treatment of established chronic CIPN is limited, and the prevalence of CIPN is not known. Here we used a systematic review to identify studies reporting the prevalence of CIPN. We searched Embase, Medline, CAB Abstracts, CINAHL, PubMed central, Cochrane Library, and Web of Knowledge for relevant references and used random-effects meta-regression to estimate overall prevalence. We assessed study quality using the CONSORT and STROBE guidelines, and we report findings according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. We provide a qualitative summary of factors reported to alter the risk of CIPN. We included 31 studies with data from 4179 patients in our analysis. CIPN prevalence was 68.1% (57.7-78.4) when measured in the first month after chemotherapy, 60.0% (36.4-81.6) at 3months and 30.0% (6.4-53.5) at 6months or more. Different chemotherapy drugs were associated with differences in CIPN prevalence, and there was some evidence of publication bias. Genetic risk factors were reported in 4 studies. Clinical risk factors, identified in 4 of 31 studies, included neuropathy at baseline, smoking, abnormal creatinine clearance, and specific sensory changes during chemotherapy. Although CIPN prevalence decreases with time, at 6months 30% of patients continue to suffer from CIPN. Routine CIPN surveillance during post-chemotherapy follow-up is needed. A number of genetic and clinical risk factors were identified that require further study.

Neurological Toxicity in Metastatic Colorectal Cancer Patients Treated with Modified FOLFOX6 Plus Bevacizumab

This study was conducted to investigate the toxicity and efficacy of modified FOLFOX6 plus bevacizumab in patients with metastatic colorectal cancer with particular regard to oxaliplatin-induced neuropathy. Toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) (version 3.0). The evaluation was especially focused on grade 2 oxaliplatin-induced neuropathy. The estimated median treatment time to occurrence of grade 2 sensory neuropathy was 7.3 months. The estimated median cumulative dose to occurrence of grade 2 sensory neuropathy was 931 mg/m(2). This study clarified the treatment time from first dose as well as the cumulative dose of oxaliplatin leading to grade 2 neuropathy. It may be important to institute some clinical countermeasures when grade 2 neuropathy occurs so as to reduce the chance of progression to irreversible grade 3 neuropathy.

Early predictors of oxaliplatin-induced cumulative neuropathy in colorectal cancer patients

OBJECTIVES

Peripheral neuropathy ranks among the most common dose-limiting and disabling side-effect of oxaliplatin (OXA)-based chemotherapy. The aim of this prospective, multicentre study was to define early clinical and neurophysiological markers that may help to identify patients at risk of developing severe, treatment emergent, cumulative OXA-induced peripheral neuropathy (OXAIPN).

METHODS

200 colorectal cancer patients, scheduled to receive OXA-based chemotherapy, were prospectively followed. Detailed neurological assessment employing the clinical Total Neuropathy Score (TNSc), oncological rating scales (National Common Institute-Common Toxicity Criteria V.3) and nerve conduction studies (NCS) were performed at baseline, mid-treatment and at the end of chemotherapy. Symptoms of OXA-induced acute neurotoxicity were systematically recorded.

RESULTS

According to TNSc, 36 (18%) patients developed grade 3 OXAIPN. These patients were predominantly men (p=0.005), presented a significant decrease in all NCS (p<0.001), reported more acute neuropathic symptoms (p<0.001) and received higher OXA cumulative dose (p=0.003). Multivariate analysis showed that three variables obtained at intermediate follow-up, namely, the number of acute symptoms (OR 1.9; CI 95% 1.2 to 3.2; p=0.012) and the >30% decrease in sensory nerve action potential amplitude from the baseline value in radial (OR 41.4; CI 95% 4.98 to 343.1; p=0.001) and dorsal sural nerves (OR 24.96; CI 95% 2.6 to 239.4; p=0.005) were independently associated with the risk of developing severe OXAIPN.

CONCLUSIONS

High-grade OXA neurotoxicity can be predicted by clinical and neurophysiological information obtained at mid-treatment. Neurological assessment of acute neuropathy symptoms and radial and dorsal sural nerves NCS should be carefully monitored to predict and hopefully prevent the induction of severe OXAIPN.

Chemotherapy-induced peripheral neuropathy in adults: a comprehensive update of the literature

Commonly used chemotherapeutic agents in oncology/hematology practice, causing toxic peripheral neuropathy, include taxanes, platinum compounds, vinca alkaloids, proteasome inhibitors, and antiangiogenic/immunomodulatory agents. This review paper intends to put together and discuss the spectrum of chemotherapy-induced peripheral neuropathy (CIPN) characteristics so as to highlight areas of future research to pursue on the topic. Current knowledge shows that the pathogenesis of CIPN still remains elusive, mostly because there are several sites of involvement in the peripheral nervous system. In any case, it is acknowledged that the dorsal root ganglia of the primary sensory neurons are the most common neural targets of CIPN. Both the incidence and severity of CIPN are clinically under- and misreported, and it has been demonstrated that scoring CIPN with common toxicity scales is associated with significant inter-observer variability. Only a proportion of chemotherapy-treated patients develop treatment-emergent and persistent CIPN, and to date it has been impossible to predict high-and low-risk subjects even within groups who receive the same drug regimen. This issue has recently been investigated in the context of pharmacogenetic analyses, but these studies have not implemented a proper methodological approach and their results are inconsistent and not really clinically relevant. As such, a stringent approach has to be implemented to validate that information. Another open issue is that, at present, there is insufficient evidence to support the use of any of the already tested chemoprotective agents to prevent or limit CIPN. The results of comprehensive interventions, including clinical, neurophysiological, and pharmacogenetic approaches, are expected to produce a consistent advantage for both doctors and patients and thus allow the registration and analysis of reliable data on the true characteristics of CIPN, eventually leading to potential preventive and therapeutic interventions.

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.

Persistent chemoneuropathy in patients receiving the plant alkaloids paclitaxel and vincristine

PURPOSE

Chemoneuropathy remains a painful, burdensome complication of cancer treatment for patients receiving a range of chemotherapeutics, yet the cause and persistence of this condition are not fully documented. This study was designed to quantify the longevity of and contributions to neuropathy following treatment with the plant alkaloids paclitaxel and vincristine.

METHODS

Quantitative sensory testing was conducted approximately 18 months apart on 14 patients, seven of which had been treated with paclitaxel and seven with vincristine and compared to data from 18 healthy control subjects. In addition, skin biopsies were obtained to investigate changes in the density of Meissner's corpuscles and epidermal nerve fibers (ENFs), the loss of which is thought to contribute to multiple forms of neuropathy.

RESULTS

Impairments in motor skills, as measured by a grooved peg-board, were found. Deficits in touch detection were observed using von Frey monofilaments, as were changes in sharpness detection using a weighted needle device. Using a Peltier device, warmth and heat detection were impaired. These deficits were consistent across time. Remarkably, the average length of time patients reported painful neuropathy was over four and a half years. Skin biopsies were found to be deficient in Meissner's corpuscles and ENFs.

CONCLUSIONS

The combination of widespread deficits in sensory testing and decreases in skin innervation for cancer patients receiving paclitaxel or vincristine document a persistent polyneuropathy which severely impacts these patients. Decreases in Meissner's corpuscles and ENFs indicate a possible mechanism for the neuropathy.

Peripheral neurotoxicity of oxaliplatin in combination with 5-fluorouracil (FOLFOX) or capecitabine (XELOX): a prospective evaluation of 150 colorectal cancer patients

BACKGROUND

To report our prospective experience on the incidence and pattern of oxaliplatin (OXA)-induced peripheral neuropathy (OXA-IPN) in patients with colorectal cancer (CRC) treated with either FOLFOX-4 or XELoda + OXaliplatin (XELOX).

PATIENTS AND METHODS

One hundred and fifty patients scheduled to be treated with either FOLFOX or XELOX for CRC were prospectively monitored at baseline and followed-up during chemotherapy. The incidence and severity of symptoms secondary to OXA-IPN were recorded using three different types of assessment, i.e. the motor and neurosensory National Cancer Institute common toxicity criteria, version 3.0 (NCI-CTCv3), the clinical version of the total neuropathy score (TNSc) and electrophysiological scores.

RESULTS

Patients treated with either FOLFOX-4 or XELOX manifested similar incidence rates and severities of acute OXA-IPN. However, FOLFOX-4 was associated with increased incidence of chronic neurotoxicity, compared with XELOX-treated patients (n = 64/77 versus 44/73; P = 0.002), at a very similar OXA median cumulative dose during both regimens. Both the NCI-CTCv3 and TNSc demonstrated that the severity of cumulative OXA-IPN in FOLFOX-4-treated patients is higher than in those treated with XELOX.

CONCLUSION

The incidence of acute neurotoxicity during FOLFOX-4 therapy is similar to XELOX. However, it seems that FOLFOX-4 is more neurotoxic than XELOX in terms of cumulative OXA-IPN, despite comparable OXA cumulative dose.

Clinical pattern and associations of oxaliplatin acute neurotoxicity: a prospective study in 170 patients with colorectal cancer

BACKGROUND

The objective of the current prospective, multicenter, international study was to trace the incidence and severity of acute oxaliplatin-induced peripheral neuropathy (OXLIPN) and to determine its clinical pattern. The authors also specifically tested whether patients who had more symptoms of acute OXLIPN eventually would develop a more severe chronic, cumulative form of OXLIPN.

METHODS

One hundred seventy patients (mean ± standard deviation age, 63.7 ± 8.7 years) who were scheduled to receive either combined leucovorin, 5-fluoruracil, and oxaliplatin (FOLFOX) or combined capecitabine and oxaliplatin (XELOX) for metastatic colorectal cancer were monitored prospectively at baseline and were followed in 4 European sites. The incidence of hyperexcitability symptoms secondary to acute OXLIPN was assessed by using a descriptive questionnaire (yes/no question) at each clinical evaluation. Motor and neurosensory criteria according to version 3 of the National Cancer Institute's Common Toxicity Criteria were applied to clinically grade the severity of OXLIPN.

RESULTS

Acute OXLIPN was present in 146 of 170 patients (85.9%). The vast majority of these patients manifested cold-induced perioral (95.2%) or pharyngolaryngeal (91.8%) dysesthesias. Severe acute OXLIPN that required prolongation of oxaliplatin infusion from 2 hours to 4 to 6 hours occurred in 32 of 146 patients (21.9%). The increased number of acute OXLIPN symptoms was correlated significantly (Spearman rho correlation coefficient [r]) with both the development (r = 0.602; P < .001) and the degree of the chronic, cumulative form (r = 0.702; P < .001).

CONCLUSIONS

The current results indicated that the vast majority of patients with colorectal cancer who receive oxaliplatin-based chemotherapy will manifest symptoms of a transient acute syndrome soon after oxaliplatin administration. Patients who have a more complex combination of acute phenomena related to axonal hyperexcitability are those who eventually develop more severe OXLIPN. Therefore, it may be advisable to test agents against acute OXLIPN to verify their effects on the chronic form.

Chemotherapy-induced peripheral neurotoxicity can be misdiagnosed by the National Cancer Institute Common Toxicity scale

The assessment of chemotherapy-induced peripheral neurotoxicity (CIPN) is still uncertain as several of the most frequently used scales do not rely on a formal neurological evaluation and depend on patients' reports and examiners' interpretations. The aim of this study was to compare the assessment of CIPN using the National Cancer Institute Common Toxicity Criteria (NCI-CTC) scale and a formal neurological assessment scored with the Total Neuropathy Score (TNS, i.e., a composite scale designed to grade the impairment in neuropathy patients) to identify possible discrepancies in the diagnosis. In this prospective study, 155 patients treated with cisplatin/carboplatin or with paclitaxel/docetaxel and CIPN were examined in a collaborative oncological/neurological multi-center trial using the NCI-CTC scale and the TNS; the results were then extensively compared. We evidenced that the TNS allows possible misdiagnosed neuropathies to be revealed. In fact, the NCI-CTC evaluation performed by experienced examiners overestimated the occurrence of motor neuropathy, possibly because of the presence of confounding factors (e.g., fatigue, depression, cachexia), which might be difficult to be ruled out without a formal neurological examination. This study strongly indicates that a more formal neurological assessment of patients with CIPN than that achievable with the common toxicity scales (e.g., NCI-CTC) is advisable.