Delayed recovery and increased severity of Paclitaxel-induced peripheral neuropathy in patients with diabetes

CYP3A genetic variation and taxane-induced peripheral neuropathy: a systematic review, meta-analysis, and candidate gene study

Background: Taxane-induced peripheral neuropathy (TIPN) is an important cause of premature treatment cessation and dose-limitation in cancer therapy. It also reduces quality of life and survivorship in affected patients. Genetic polymorphisms in the CYP3A family have been investigated but the findings have been inconsistent and contradictory. Methods: A systematic review identified 12 pharmacogenetic studies investigating genetic variation in CYP3A4*22 and CYP3A5*3 and TIPN. In our candidate gene study, 288 eligible participants (211 taxane participants receiving docetaxel or paclitaxel, and 77 control participants receiving oxaliplatin) were successfully genotyped for CYP3A4*22 and CYP3A5*3. Genotyping data was transformed into a combined CYP3A metaboliser phenotype: Poor metabolisers, intermediate metabolisers and extensive metabolisers. Individual genotypes and combined CYP3A metaboliser phenotypes were assessed in relation to neurotoxicity, including by meta-analysis where possible. Results: In the systematic review, no significant association was found between CYP3A5*3 and TIPN in seven studies, with one study reporting a protective association. For CYP3A4*22, one study has reported an association with TIPN, while four other studies failed to show an association. Evaluation of our patient cohort showed that paclitaxel was found to be more neurotoxic than docetaxel (p < 0.001). Diabetes was also significantly associated with the development of TIPN. The candidate gene analysis showed no significant association between either SNP (CYP3A5*3 and CYP3A4*22) and the development of TIPN overall, or severe TIPN. Meta-analysis showed no association between these two variants and TIPN. Transformed into combined CYP3A metaboliser phenotypes, 30 taxane recipients were poor metabolisers, 159 were intermediate metabolisers, and 22 were extensive metabolisers. No significant association was observed between metaboliser status and case-control status. Summary: We have shown that the risk of peripheral neuropathy during taxane chemotherapy is greater in patients who have diabetes. CYP3A genotype or phenotype was not identified as a risk factor in either the candidate gene analysis or the systematic review/meta-analysis, although we cannot exclude the possibility of a minor contribution, which would require a larger sample size.

Influence of Diabetes Mellitus on Oncological Outcomes for Patients Living With Cancer

PURPOSE

The purpose of this meta-analysis was to examine the association between preexisting diabetes in persons living with cancer on diabetes and oncology-related health outcomes. Understanding this association is of priority because the incidence of both cancer and diabetes mellitus is increasing worldwide.

METHODS

A comprehensive review of the literature was conducted in collaboration with an expert health sciences librarian. Two authors independently conducted the screening, data collection, and extraction processes. The risk of bias was assessed using several tools, depending on the study design. Relative risks with 95% confidence intervals were calculated. The alpha threshold was 0.05. All analyses were performed using R statistical software (Metaphor and Demeter packages).

RESULTS

A total of 45 studies met the selection criteria, but 23 were excluded from the synthesis because they did not have the ranked outcome or correct comparison (persons with and without diabetes), totaling 22 studies included in the meta-analysis. In comparison to participants without preexisting diabetes, participants with preexisting diabetes and cancer were found to have a significantly higher risk of infection and cardiovascular, neurological, gastrointestinal, hepatic, and renal complications. Concurrent preexisting diabetes and cancer were also associated with increased health care service utilization and length of hospital stay.

CONCLUSION

The findings from this review highlight the importance of optimal concurrent management of both diseases by overcoming the compartmentalization of medical specializations through (1) integrated, multidisciplinary, shared, and coordinated clinical care pathways between oncology and diabetes health care providers/teams and (2) the continued development of evidence-based clinical guidelines.

Update on Toxic Neuropathies

Purpose of Review

Toxic neuropathies are an important preventable and treatable form of peripheral neuropathy. While many forms of toxic neuropathies have been recognized for decades, an updated review is provided to increase vigilant in this area of neurology. A literature review was conducted to gather recent information about toxic neuropathies, which included the causes, clinical findings, and treatment options in these conditions.

Recent Findings

Toxic neuropathies continue to cause significant morbidity throughout the world and the causative agents, particularly with regards to medications, do not appear to be diminishing. A wide variety of causes of toxic neuropathies exist, which include alcohol, industrial chemicals, biotoxins, and medications. Unfortunately, no breakthrough treatments have been developed and prevention and symptom management remain the standard of care.

Summary

A detailed medication, occupational and hobby exposure history is critical to identifying toxic neuropathies. Increased research is warranted to identify mechanisms of neurotoxic susceptibility and potential common pathomechanistic pathways for treatment across diverse toxic neuropathies.

Chemotherapy-Induced Peripheral Neuropathy: Epidemiology, Pathomechanisms and Treatment

PURPOSE

This review provides an update on the current clinical, epidemiological and pathophysiological evidence alongside the diagnostic, prevention and treatment approach to chemotherapy-induced peripheral neuropathy (CIPN).

FINDINGS

The incidence of cancer and long-term survival after treatment is increasing. CIPN affects sensory, motor and autonomic nerves and is one of the most common adverse events caused by chemotherapeutic agents, which in severe cases leads to dose reduction or treatment cessation, with increased mortality. The primary classes of chemotherapeutic agents associated with CIPN are platinum-based drugs, taxanes, vinca alkaloids, bortezomib and thalidomide. Platinum agents are the most neurotoxic, with oxaliplatin causing the highest prevalence of CIPN. CIPN can progress from acute to chronic, may deteriorate even after treatment cessation (a phenomenon known as coasting) or only partially attenuate. Different chemotherapeutic agents share both similarities and key differences in pathophysiology and clinical presentation. The diagnosis of CIPN relies heavily on identifying symptoms, with limited objective diagnostic approaches targeting the class of affected nerve fibres. Studies have consistently failed to identify at-risk cohorts, and there are no proven strategies or interventions to prevent or limit the development of CIPN. Furthermore, multiple treatments developed to relieve symptoms and to modify the underlying disease in CIPN have failed.

IMPLICATIONS

The increasing prevalence of CIPN demands an objective approach to identify at-risk patients in order to prevent or limit progression and effectively alleviate the symptoms associated with CIPN. An evidence base for novel targets and both pharmacological and non-pharmacological treatments is beginning to emerge and has been recognised recently in publications by the American Society of Clinical Oncology and analgesic trial design expert groups such as ACTTION.

Chemotherapy-Induced Neuropathy and Diabetes: A Scoping Review

Although cancer and diabetes are common diseases, the relationship between diabetes, neuropathy and the risk of developing peripheral sensory neuropathy while or after receiving chemotherapy is uncertain. In this review, we highlight the effects of chemotherapy on the onset or progression of neuropathy in diabetic patients. We searched the literature in Medline and Scopus, covering all entries until 31 January 2021. The inclusion and exclusion criteria were: (1) original article (2) full text published in English or Spanish; (3) neuropathy was specifically assessed (4) the authors separately analyzed the outcomes in diabetic patients. A total of 259 papers were retrieved. Finally, eight articles fulfilled the criteria, and four more articles were retrieved from the references of the selected articles. The analysis of the studies covered the information about neuropathy recorded in 768 cancer patients with diabetes and 5247 control cases (non-diabetic patients). The drugs investigated are chemotherapy drugs with high potential to induce neuropathy, such as platinum derivatives and taxanes, which are currently the mainstay of treatment of various cancers. The predisposing effect of co-morbid diabetes on chemotherapy-induced peripheral neuropathy depends on the type of symptoms and drug used, but manifest at any drug regimen dosage, although greater neuropathic signs are also observed at higher dosages in diabetic patients. The deleterious effects of chemotherapy on diabetic patients seem to last longer, since peripheral neuropathy persisted in a higher proportion of diabetic patients than non-diabetic patients for up to two years after treatment. Future studies investigating the risk of developing peripheral neuropathy in cancer patients with comorbid diabetes need to consider the duration of diabetes, cancer-induced neuropathic effects per se (prior chemotherapy administration), and the effects of previous cancer management strategies such as radiotherapy and surgery.

Diabetes mellitus as a risk factor for chemotherapy-induced peripheral neuropathy: a meta-analysis

BACKGROUND

To identify the association between diabetes mellitus (DM) and the risk of chemotherapy-induced peripheral neuropathy (CIPN) through a systematic review and meta-analysis.

METHODS

An electronic literature search was conducted in PubMed, Embase, Web of Science, the Wanfang database, the VIP Journals database (CQVIP), the China National Knowledge Infrastructure (CNKI) database, and the China Biology Medicine database (Sinomed) between January 2010 and January 2021. Articles were included if they investigated CIPN and DM. Stata 15.1 was used to analyze the data.

RESULTS

We examined 8923 cancer patients from 25 studies comprising 9 cohort studies and 16 case-control studies. Meta-analysis showed that there was a statistically significant positive correlation between DM and CIPN (odds ratio [OR] = 1.60, 95% confidence interval [CI] = 1.38-1.85, P < 0.001). Egger's test (P = 0.824) showed no evidence of publication bias. The positive associations did not significant differ by study type, study quality, evaluation instrument, and type of antineoplastic drug. Omission of any single study had little effect on the combined risk estimate. Little evidence of heterogeneity was observed.

CONCLUSION

This meta-analysis provides evidence of a significant positive association between DM and risk of CIPN. Furthermore, a more detailed evaluation is warranted for cancer patients with diabetes when they are treated with antineoplastic drugs that have the potential to cause peripheral neuropathy.

Relative Risk of Peripheral Neuropathy With Ado-Trastuzumab Emtansine (T-DM1) Compared to Taxane-Based Regimens in Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Cancers: A Systematic Review and Meta-Analysis

Background

Peripheral neuropathy (PN), especially peripheral sensory neuropathy (PSN), is significant toxicity of taxanes, the most used class of microtubule inhibitors for human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients. Ado-trastuzumab emtansine (T-DM1) is a HER2-targeted antibody-drug conjugate, consisting of trastuzumab and a microtubule inhibitor DM1, which has been approved for HER2-positive breast cancer. T-DM1 has also been found to cause significant PN, including PSN.

Methods

We conducted a systematic review and meta-analysis of phase 3 randomized controlled trials using T-DM1 in the experimental arm and a taxane-based regimen in the control arm to determine the relative risk of PN and PSN associated with T-DM1 as compared to taxanes. A total of 1,857 patients were included in the analysis. The Cochran-Mantel-Haenszel method and the random-effects model were used to calculate the pooled risk ratio (RR) with a 95% confidence interval (CI) for all-grade and grade ≥3 PN and PSN. 

Results

The relative risks of all-grade PN and all-grade PSN were lower with T-DM1 compared to taxanes. The pooled RR of all-grade PN was 0.59, 95% CI: 0.39-0.89, P = 0.01, and the pooled RR of all-grade PSN was 0.58, 95% CI: 0.46-0.74, P < 0.0001.

Conclusions

Our meta-analysis demonstrated that T-DM1 is associated with a relatively lower risk of all-grade PN and PSN than the taxane-based regimens for HER2-positive cancers. It could be an area of consideration in selecting therapy for HER2-positive breast cancer patients at high risk of developing or having pre-existing PN and PSN.

Taxane and epothilone-induced peripheral neurotoxicity: From pathogenesis to treatment

Taxane-induced peripheral neurotoxicity (TIPN) is the most common non-hematological side effect of taxane-based chemotherapy, and may result in dose reductions and discontinuations, having as such a detrimental effect on patients' overall survival. Epothilones share similar mechanism of action with taxanes. The typical TIPN clinical presentation is mainly comprised of numbness and paresthesia, in a stocking-and-glove distribution and may progress more proximally over time, with paclitaxel being more neurotoxic than docetaxel. Motor and autonomic involvement is less common, whereas an acute taxane-induced acute pain syndrome is frequent. Patient reported outcomes questionnaires, clinical evaluation, and instrumental tools offer complementary information in TIPN. Its electrodiagnostic features include reduced/abolished sensory action potentials, and less prominent motor involvement, in keeping with a length-dependent, axonal dying back predominately sensory neuropathy. TIPN is dose-dependent and may be reversible within months after the end of chemotherapy. The single and cumulative delivered dose of taxanes is considered the main risk factor of TIPN development. Apart from the cumulative dose, other risk factors for TIPN include demographic, clinical, and pharmacogenetic features with several single-nucleotide polymorphisms potentially linked with increased susceptibility of TIPN. There are currently no neuroprotective strategies to reduce the risk of TIPN, and symptomatic treatments are very limited. This review critically examines the pathogenesis, incidence, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of TIPN.

Receipt of Guideline-Concordant Care Among Older Women With Stage I-III Breast Cancer: A Population-Based Study

Background: This study examined receipt of guideline-concordant care (GCC) according to evidence-based treatment guidelines and quality measures and specific types of treatment among older women with breast cancer. Patients and Methods: A total of 142,433 patients aged ≥66 years diagnosed with stage I-III breast cancer between 2007 and 2011 were identified in the SEER-Medicare linked database. Algorithms considering cancer characteristics and the appropriate course of care as per guidelines versus actual care received determined receipt of GCC. Multivariable logistic regression estimated the likelihood of GCC and specific types of treatment for women aged ≥75 versus 66 to 74 years. Results: Overall, 39.7% of patients received GCC. Patients diagnosed at stage II or III, with certain preexisting conditions, and of nonwhite race were less likely to receive GCC. Patients with hormone-negative tumors, higher grade tumors, and greater access to oncology care resources were more likely to receive GCC. Patients aged ≥75 years were approximately 40% less likely to receive GCC or adjuvant endocrine therapy, 78% less likely to have any surgery, 61% less likely to have chemotherapy, and about half as likely to have radiation therapy than those aged 66 to 74 years. Conclusions: Fewer than half of older women with breast cancer received GCC, with the lowest rates observed among the oldest age groups, racial/ethnic minorities, and women with later-stage cancers. However, patients with more aggressive tumor characteristics and greater access to oncology resources were more likely to receive GCC. Considering that older women have the highest incidence of breast cancer and that many are diagnosed at stages requiring more aggressive treatment, efforts to increase rates of earlier stage diagnosis and the development of less toxic treatments could help improve GCC and survival while preserving quality of life.

The effect of diabetes mellitus on pharmacokinetics, pharmacodynamics and adverse drug reactions of anticancer drugs

Diabetes mellitus (DM) and cancer are global problems carrying huge human, social, and economic impact. Type 2 diabetes (T2DM) is associated with an increased risk for a number of cancers, including breast, pancreatic, and liver cancer. Moreover, adverse drug reactions are higher in paitents with cancer with T2DM compared to cancer patients without T2DM. Cellular mechanisms of hyperglycemia and chemotherapy efficacy may be different depending upon the particular cancer type and the condition of the patient. This review evaluates the effect of DM on the pharmacokinetic, pharmacodynamic, and adverse drug reactions of commonly used anticancer drugs such as cisplatin, methotrexate, paclitaxel, doxorubicin, and adriamycin in both clinical and animal models. A literature search was conducted in scientific databases including Web of Science, PubMed, Scopus, and Google Scholar including the relevant keywords. The results of the effectiveness of anticancer therapies in patients with DM are, however, inconsistent because DM can negatively impact multiple diverse entities including nerves and vascular structures, insulin-like growth factor 1, the function of the innate immune system, drug pharmacokinetics, the expression levels of hepatic CYP₄₅₀ , Mdr _1b and enzymes that then lead to drug toxicity. However, in a few circumstances, DM led to attenuation of the toxicity of anticancer drugs secondary to attenuation of the energy-dependent renal uptake process. Overall, the impact of DM on patients with cancer is variable because of the diverse types of cancers and the spectrum of anticancer drugs. With respect to the evidence for cancer involvement in DM pathophysiology and the response to anticancer treatment in patients with DM, many questions still remain and further clinical trials are needed.

Concomitant Medications and Risk of Chemotherapy-Induced Peripheral Neuropathy

BACKGROUND

Peripheral neuropathy is the dose-limiting toxicity of many oncology drugs, including paclitaxel. There is large interindividual variability in the neuropathy, and several risk factors have been proposed; however, many have not been replicated. Here we present a comprehensive study aimed at identifying treatment and physiopathology-related paclitaxel-induced neuropathy risk factors in a large cohort of well-characterized patients.

PATIENTS AND METHODS

Analyses included 503 patients with breast or ovarian cancer who received paclitaxel treatment. Paclitaxel dose modifications caused by the neuropathy were extracted from medical records and patients self-reported neuropathy symptoms were collected. Multivariate logistic regression analyses were performed to identify concomitant medications and comorbidities associated with paclitaxel-induced neuropathy.

RESULTS

Older patients had higher neuropathy: for each increase of 1 year of age, the risk of dose modifications and grade 3 neuropathy increased 4% and 5%, respectively. Cardiovascular drugs increased the risk of paclitaxel dose reductions (odds ratio [OR], 2.51; p = .006), with a stronger association for beta-adrenergic antagonists. The total number of concomitant medications also showed an association with dose modifications (OR, 1.25; p = .012 for each concomitant drug increase). A dose modification predictive model that included the new identified factors gave an area under the curve of 0.74 (p = 1.07 × 10^-10). Preexisting nerve compression syndromes seemed to increase neuropathy risk.

CONCLUSION

Baseline characteristics of the patients, including age and concomitant medications, could be used to identify individuals at high risk of neuropathy, personalizing chemotherapy treatment and reducing the risk of severe neuropathy.

IMPLICATIONS FOR PRACTICE

Peripheral neuropathy is a common adverse effect of many cancer drugs, including chemotherapeutics, targeted therapies, and immune checkpoint inhibitors. About 40% of survivors of cancer have functional deficits caused by this toxicity, some of them irreversible. Currently, there are no effective treatments to prevent or treat this neuropathy. This study, performed in a large cohort of well-characterized patients homogenously treated with paclitaxel, identified concomitant medications, comorbidities, and demographic factors associated with peripheral neuropathy. These factors could serve to identify patients at high risk of severe neuropathy for whom alternative non-neurotoxic alternatives may be considered.

Differential Morphological and Biochemical Recovery from Chemotherapy-Induced Peripheral Neuropathy Following Paclitaxel, Ixabepilone, or Eribulin Treatment in Mouse Sciatic Nerves

The reversibility of chemotherapy-induced peripheral neuropathy (CIPN), a disabling and potentially permanent side effect of microtubule-targeting agents (MTAs), is becoming an increasingly important issue as treatment outcomes improve. The molecular mechanisms regulating the variability in time to onset, severity, and time to recovery from CIPN between the common MTAs paclitaxel and eribulin are unknown. Previously (Benbow et al. in Neurotox Res 29:299-313, 2016), we found that after 2 weeks of a maximum tolerated dose (MTD) in mice, paclitaxel treatment resulted in severe reductions in axon area density, higher frequency of myelin abnormalities, and increased numbers of Schwann cell nuclei in sciatic nerves. Biochemically, eribulin induced greater microtubule-stabilizing effects than paclitaxel. Here, we extended these comparative MTD studies to assess the recovery from these short-term effects of paclitaxel, eribulin, and a third MTA, ixabepilone, over the course of 6 months. Paclitaxel induced a persistent reduction in axon area density over the entire 6-month recovery period, unlike ixabepilone- or eribulin-treated animals. The abundance of myelin abnormalities rapidly declined after cessation of all drugs but recovered most slowly after paclitaxel treatment. Paclitaxel- and ixabepilone- but not eribulin-treated animals exhibited increased Schwann cell numbers during the recovery period. Tubulin composition and biochemistry rapidly returned from MTD-induced levels of α-tubulin, acetylated α-tubulin, and end-binding protein 1 to control levels following cessation of drug treatment. Taken together, sciatic nerve axons recovered more rapidly from morphological effects in eribulin- and ixabepilone-treated animals than in paclitaxel-treated animals and drug-induced increases in protein expression levels following paclitaxel and eribulin treatment were relatively transient.

Two-Year Trends of Taxane-Induced Neuropathy in Women Enrolled in a Randomized Trial of Acetyl-L-Carnitine (SWOG S0715)

Background

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and disabling side effect of taxanes. Acetyl-L-carnitine (ALC) was unexpectedly found to increase CIPN in a randomized trial. We investigated the long-term patterns of CIPN among patients in this trial.

Methods

S0715 was a randomized, double-blind, multicenter trial comparing ALC (1000 mg three times a day) with placebo for 24 weeks in women undergoing adjuvant taxane-based chemotherapy for breast cancer. CIPN was measured by the 11-item neurotoxicity (NTX) component of the FACT-Taxane scale at weeks 12, 24, 36, 52, and 104. We examined NTX scores over two years using linear mixed models for longitudinal data. Individual time points were examined using linear regression. Regression analyses included stratification factors and the baseline score as covariates. All statistical tests were two-sided.

Results

Four-hundred nine subjects were eligible for evaluation. Patients receiving ALC had a statistically significantly (P = .01) greater reduction in NTX scores (worse CIPN) of -1.39 points (95% confidence interval [CI] = -2.48 to -0.30) than the placebo group. These differences were particularly evident at weeks 24 (-1.68, 95% CI = -3.02 to -0.33), 36 (-1.37, 95% CI = -2.69 to -0.04), and 52 (-1.83, 95% CI = -3.35 to -0.32). At 104 weeks, 39.5% on the ALC arm and 34.4% on the placebo arm reported a five-point (10%) decrease from baseline. For both treatment groups, 104-week NTX scores were statistically significantly different compared with baseline (P < .001).

Conclusions

For both groups, NTX scores were reduced from baseline and remained persistently low. Twenty-four weeks of ALC therapy resulted in statistically significantly worse CIPN over two years. Understanding the mechanism of this persistent effect may inform prevention and treatment strategies. Until then, the potential efficacy and harms of commonly used supplements should be rigorously studied.

Clinical and genetic predictors of paclitaxel neurotoxicity based on patient- versus clinician-reported incidence and severity of neurotoxicity in the ICON7 trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity of paclitaxel, with no reliable method to identify at-risk patients. We investigated the incidence and risk factors including genetic polymorphisms associated with the development of CIPN based on clinician and patient reporting of neuropathic symptoms.

PATIENTS AND METHODS

Risk factors for the development of CIPN were examined in 454 patients treated with paclitaxel/carboplatin from the International Collaboration on Ovarian Neoplasms 7 (ICON7) trial. Neuropathy was graded by clinicians by standard adverse event reporting and by patients utilising OV28 questionnaire. Genetic risk factors were examined by selecting six single nucleotide polymorphisms in genes associated with microtubule function. Risk factors were assessed via dose-to-event cox regression models.

RESULTS

Grade >2 neuropathy was reported by clinicians in 28% of patients, while 67% of patients reported 'quite a bit' or 'very much' tingling or numbness. Agreement between clinicians and patients was poor (κ = 0.236, 95% confidence interval, 0.177-0.296, P < 0.001). Older age, bevacizumab treatment and bowel resection were associated with clinician reported CIPN, while older age and volume of residual disease were associated with patient-reported neuropathy. There were no significant associations between clinician-reported neuropathy or patient-reported neuropathy and TUBB2, CEP72 or individual MAPT or GSK3B SNPs, however MAPT additive polymorphisms were associated with patient-reported neuropathy and GSK3B additive polymorphisms were associated with clinician reported CIPN.

CONCLUSIONS

There was significant discordance between patient- and clinician-reported neurotoxicity. The lack of consensus regarding optimal outcome measures and whose opinion with regard to CIPN takes precedence is a limitation in the investigation of risk factors for CIPN. Care must be taken to select and include patient-reported outcome measures in CIPN assessment to enable accurate identification of genetic and other risk factors for neuropathy.

Genetic polymorphisms of SCN9A are associated with oxaliplatin-induced neuropathy

Background

Oxaliplatin is a chemotherapy agent active against digestive tumors. Peripheral neuropathy is one of the most important dose-limiting toxicity of this drug. It occurs in around 60–80% of the patients, and 15% of them develop severe neuropathy. The pathophysiology of oxaliplatin neurotoxicity remains unclear. SCN9A is a gene codifying for a subtype sodium channel (type IX, subunit α) and mutations in this gene are involved in neuropathic perception. In this study we investigated whether SCN9A genetic variants were associated with risk of neurotoxicity in patients diagnosed of cancer on treatment with oxaliplatin.

Methods

Blood samples from 94 patients diagnosed of digestive cancer that had received oxaliplatin in adjuvant or metastatic setting were obtained from three hospitals in Madrid. These patients were classified into two groups: “cases” developed oxaliplatin-induced grade 3–4 neuropathy (n = 48), and “controls” (n = 46) had no neuropathy or grade 1. The neuropathy was evaluated by an expert neurologist and included a clinical examination and classification according to validated neurological scales: National Cancer Institute Common Toxicity Criteria (NCI-CTC), Oxaliplatin-Specific Neurotoxicity Scale (OSNS) and Total Neuropathy score (TNS). Genotyping was performed for 3 SCN9A missense polymorphisms: rs6746030 (R1150W), rs74401238 (R1110Q) and rs41268673 (P610T), and associations between genotypes and neuropathy were evaluated.

Results

We found that SCN9A rs6746030 was associated with protection for severe neuropathy (OR = 0.39, 95% CI = 0.16–0.96; p = 0.041). Multivariate analysis adjusting for diabetes provided similar results (p = 0.036). No significant differences in neuropathy risk were detected for rs74401238 and rs41268673.

Conclusion

SCN9A rs6746030 was associated with protection for severe oxaliplatin-induced peripheral neuropathy. The validation of this exploratory study is ongoing in an independent series.

Comorbidities and Risk of Chemotherapy-Induced Peripheral Neuropathy Among Participants 65 Years or Older in Southwest Oncology Group Clinical Trials

BACKGROUND

Neuropathy is a debilitating toxicity associated with various chemotherapy agents. We evaluated the association between common comorbid conditions and the development of peripheral neuropathy in patients treated with taxane-based chemotherapy.

METHODS

We examined the Southwest Oncology Group database to identify phase II and III trials that included taxane therapy from 1999 to 2011. We linked the Southwest Oncology Group clinical records to Medicare claims data according to Social Security number, sex, and date of birth. The following disease conditions potentially associated with peripheral neuropathy were evaluated: diabetes, hypothyroidism, hypercholesterolemia, hypertension, varicella zoster, peripheral vascular disease, and autoimmune diseases. Multivariate logistic regression was used to model the odds of experiencing grade 2 to 4 neuropathy.

RESULTS

A total of 1,401 patients from 23 studies were included in the analysis. Patients receiving paclitaxel were more likely to experience grade 2 to 4 neuropathy compared with docetaxel (25% v 12%, respectively; OR, 2.20; 95% CI, 1.52 to 3.18; P < .001). The inclusion of a platinum agent was also associated with greater neuropathy (OR, 1.68; 95% CI, 1.18 to 2.40; P = .004). For each increase in age of 1 year, the odds of neuropathy increased 4% (P = .006). Patients with complications from diabetes had more than twice the odds of having neuropathy (OR, 2.13; 95% CI, 1.31 to 3.46; P = .002) compared with patients with no diabetes. In contrast, patients with autoimmune disease were half as likely to experience neuropathy (OR, 0.49; 95% CI, 0.24 to 1.02; P = .06). The other conditions were not associated with neuropathy.

CONCLUSION

We found that in addition to drug-related factors, age and history of diabetes were independent predictors of the development of chemotherapy-induced peripheral neuropathy. Interestingly, we also observed that a history of autoimmune disease was associated with reduced odds of neuropathy. Patients with diabetic complications may choose to avoid paclitaxel or taxane plus platinum combination therapies if other efficacious options exist.

Chemotherapy-induced peripheral neuropathy: Current status and progress

As there are increasing numbers of cancer survivors, more attention is being paid to the long term unwanted effects patients may experience as a result of their treatment and the impact these side effects can have on their quality of life. Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common long-term toxicities from chemotherapy. In this review we will briefly review the clinical presentation, evaluation and management of chemotherapy-induced peripheral neuropathy, with a focus on CIPN related to platinum and taxane agents. We will then discuss current clinical models of peripheral neuropathy and ongoing research to better understand CIPN and develop potential treatment options.

Chemotherapy-induced peripheral neuropathy after neoadjuvant or adjuvant treatment of breast cancer: a prospective cohort study

PURPOSE

The purposes of this study were to estimate the incidence of chemotherapy-induced peripheral neuropathy (CIPN) and to identify its main determinants and impact in patient-reported outcomes.

METHODS

We performed a prospective cohort study including 296 patients with incident breast cancer submitted to chemotherapy, followed for 1 year. Patients with incident CIPN were reevaluated 6 months after this diagnosis. Relative risks (RR) with 95 % confidence intervals (95 % CI) were computed to quantify the relation between different clinical characteristics and the occurrence of CIPN, using Poisson regression. The variation of patient-reported outcomes between baseline and 1-year follow-up assessments was compared between patients with and without CIPN.

RESULTS

The cumulative incidence of CIPN in the first year after diagnosis was 28.7 % (95 % CI 23.8-34.1), and more than 80 % of the patients were still symptomatic after 6 months. Among the latter, there was a significant decrease in the median total neuropathy score, clinical version (7 versus 4) between the two periods. In multivariable analysis, the risk of CIPN was higher for treatment with docetaxel (cumulative doses ≤300 mg/m(2), RR = 6.96, 95 % CI 2.53-19.10; >300 mg/m(2), RR = 13.32; 95 % CI 4.11-43.14). Alcohol consumption and diabetes were not significantly associated with CIPN. There were no significant differences in the variation of patient-reported outcomes between the baseline and 1-year follow-up evaluations.

CONCLUSIONS

CIPN was frequent in this contemporary cohort of early-stage breast cancer patients and was strongly associated with docetaxel-based regimens. Symptoms persisted for at least 6 months in most patients, but severity was low and CIPN had no impact on patient-reported outcomes.