Chemotherapy-induced peripheral neuropathy: clinical features, diagnosis, prevention and treatment strategies

Pathobiology of cancer chemotherapy-induced peripheral neuropathy (CIPN)

Chemotherapy induced peripheral neuropathy (CIPN) is a type of neuropathic pain that is a major dose-limiting side-effect of potentially curative cancer chemotherapy treatment regimens that develops in a "stocking and glove" distribution. When pain is severe, a change to less effective chemotherapy agents may be required, or patients may choose to discontinue treatment. Medications used to alleviate CIPN often lack efficacy and/or have unacceptable side-effects. Hence the unmet medical need for novel analgesics for relief of this painful condition has driven establishment of rodent models of CIPN. New insights on the pathobiology of CIPN gained using these models are discussed in this review. These include mitochondrial dysfunction and oxidative stress that are implicated as key mechanisms in the development of CIPN. Associated structural changes in peripheral nerves include neuronopathy, axonopathy and/or myelinopathy, especially intra-epidermal nerve fiber (IENF) degeneration. In patients with CIPN, loss of heat sensitivity is a hallmark symptom due to preferential damage to myelinated primary afferent sensory nerve fibers in the presence or absence of demyelination. The pathobiology of CIPN is complex as cancer chemotherapy treatment regimens frequently involve drug combinations. Adding to this complexity, there are also subtle differences in the pathobiological consequences of commonly used cancer chemotherapy drugs, viz platinum compounds, taxanes, vincristine, bortezomib, thalidomide and ixabepilone, on peripheral nerves.

Bevacizumab-induced transient sixth nerve palsy in ovarian cancer: A case report

We report a case of transient sixth nerve palsy after systemic administration of bevacizumab. Two days after systemic administration of bevacizumab in conjunction with gemcitabine and carboplatin in a 67-year-old woman with recurrent primary ovarian cancer, the patient developed sixth nerve palsy. After bevacizumab was stopped, the complete left sixth nerve palsy resolved spontaneously over the course of 3 months. This is the first reported case of bevacizumab-induced cranial sixth nerve palsy in the treatment of gynecologic malignancy.

Mononeuritis multiplex in a patient with B-cell prolymphocytic leukaemia: a diagnostic challenge

B-cell prolymphocytic leukaemia (BPLL) is a haematological malignancy defined as lymphocytosis and splenomegaly with >55% circulating cells being clonal prolymphocytes of B-cell origin. The evolution of this disease is more aggressive than chronic lymphocytic leukaemia. We reported a case of a 62-year-old man with BPLL who, on treatment, attained cytological, immunophenotypic and complete cytogenetic remission. He subsequently developed an asymmetric sensorimotor neurological disorder, suggestive of lymphomatous infiltration (neurolymphocytosis). Repetition of the MRI and the electromyography was essential for diagnosis. Progressive mononeuritis multiplex in B-cell leukaemias/lymphomas is rare and may be the only presenting symptom of relapsed or progressive disease. Repeat imaging studies based on judicious evaluation of the clinical scenario for exclusion of other causes of neurological symptoms is necessary. This can be challenging in patients with long-standing malignancies who have received multiple courses of chemotherapy and/or radiotherapy.

Genome-wide association study identifies ephrin type A receptors implicated in paclitaxel induced peripheral sensory neuropathy

BACKGROUND

Peripheral neuropathy is the dose limiting toxicity of paclitaxel, a chemotherapeutic drug widely used to treat solid tumours. This toxicity exhibits great inter-individual variability of unknown origin. The present study aimed to identify genetic variants associated with paclitaxel induced neuropathy via a whole genome approach.

METHODS

A genome-wide association study (GWAS) was performed in 144 white European patients uniformly treated with paclitaxel/carboplatin and for whom detailed data on neuropathy was available. Per allele single nucleotide polymorphism (SNP) associations were assessed by Cox regression, modelling the cumulative dose of paclitaxel up to the development of grade 2 sensory neuropathy.

RESULTS

The strongest evidence of association was observed for the ephrin type A receptor 4 (EPHA4) locus (rs17348202, p=1.0×10(-6)), and EPHA6 and EPHA5 were among the top 25 and 50 hits (rs301927, p=3.4×10(-5) and rs1159057, p=6.8×10(-5)), respectively. A meta-analysis of EPHA5-rs7349683, the top marker for paclitaxel induced neuropathy in a previous GWAS (r(2)=0.79 with rs1159057), gave a hazard ratio (HR) estimate of 1.68 (p=1.4×10(-9)). Meta-analysis of the second hit of this GWAS, XKR4-rs4737264, gave a HR of 1.71 (p=3.1×10(-8)). Imputed SNPs at LIMK2 locus were also strongly associated with this toxicity (HR=2.78, p=2.0×10(-7)).

CONCLUSIONS

This study provides independent support of EPHA5-rs7349683 and XKR4-rs4737264 as the first markers of risk of paclitaxel induced neuropathy. In addition, it suggests that other EPHA genes also involved in axonal guidance and repair following neural injury, as well as LIMK2 locus, may play an important role in the development of this toxicity. The identified SNPs could form the basis for individualised paclitaxel chemotherapy.

The contribution of satellite glial cells to chemotherapy-induced neuropathic pain

BACKGROUND

Chemotherapy-induced peripheral neuropathy is a serious side effect in cancer treatment, a major manifestation being neuropathic pain that can be debilitating and can reduce the quality of life of the patient. Oxaliplatin and taxol are common anti-cancer drugs that induce neuropathic pain by an unknown mechanism. We tested the hypothesis that satellite glial cells in dorsal root ganglia (DRGs) are altered in chemotherapy-induced peripheral neuropathy models and contribute to neuropathic pain.

METHODS

Mice were injected with either oxaliplatin or taxol and examined at 7-30 days. Glial fibrillary acidic protein (glial activation marker) expression was determined by immunohistochemistry. Satellite glial cells in isolated DRG were injected with the fluorescent dye Lucifer yellow and the incidence of dye coupling among these cells that surround different neurons was quantified.

RESULTS

Taxol or oxaliplatin increased glial fibrillary acidic protein expression in satellite glial cells. Gap junction-mediated coupling between satellite glial cells was increased by up to fivefold after oxaliplatin and by up to twofold after taxol. This is consistent with work on other pain models showing that augmented satellite glial cell coupling contributes to chronic pain. Administration of the gap junction blocker carbenoxolone to chemotherapy-treated mice produced an analgesic-like effect.

CONCLUSIONS

We propose that increased coupling by gap junctions is part of satellite glial cell activation, and that augmented coupling contributes to the lowering of pain threshold in oxaliplatin- and taxol-treated mice. We further propose that gap junction blockers may have potential in treating chemotherapy-induced neuropathic pain.

The Lived Experience of Peripheral Neuropathy after Solid Organ Transplant

Background

The immunosuppressants required after transplant cause peripheral neuropathy with an incidence of 10% to 60%. Peripheral neuropathy adversely affects health-related quality of life in other populations.

Objective

To describe the lived experience of peripheral neuropathy after solid organ transplant.

Design

A qualitative phenomenological study with semistructured interviews. A purposive sample of 7 solid organ transplant recipients with peripheral neuropathy was recruited from 2 transplant clinics at a large Midwest tertiary care center. Interviews were audio taped and transcribed verbatim. Data were analyzed line-byline and coded by using HyperResearch 2.0.

Results

Although participants' experiences were similar to those reported by others with peripheral neuropathy, there were also unique differences. Unique to this population was unexpected onset, rapid escalation of symptoms, lack of provider monitoring, and poor provider response to reported symptoms. Their experience demonstrated that peripheral neuropathy diminished health-related quality of life. Four themes emerged from the data: (1) nothing is supposed to happen after transplant; (2) neuropathy causes me more problems than my heart; (3) maybe there is something that could help; and (4) I've learned to live with certain limitations.

Conclusion

Development of or worsening of peripheral neuropathy after solid organ transplant may decrease health-related quality of life. Follow-up care should include vigilant monitoring for signs of peripheral neuropathy. Providers need to provide early treatment, education, support, empathy, and understanding.

Considerations and controversies in the management of older patients with advanced cancer

The incidence of cancer increases with age. Oncologists need to be adept at assessing physiologic and functional capacity in older patients in order to provide safe and efficacious cancer treatment. Assessment of underlying health status is especially important for older patients with advanced cancer, for whom the benefits of treatment may be low and the toxicity of treatment high. The comprehensive geriatric assessment (CGA) is the criterion standard for evaluation of the older patient. The combined data from the CGA can be used to stratify patients into categories to better predict risk for chemotherapy toxicity as well as overall outcomes. The CGA can also be used to identify and follow-up on possible functional consequences from treatment. A variety of screening tools might be useful in the oncology practice setting to identify patients who may benefit from further testing and intervention. In this chapter, we discuss how the principles of geriatrics can help improve the clinical care of older adults with advanced cancer. Specifically, we discuss assessing tolerance for treatment, options for chemotherapy scheduling and dosing for older patients with advanced cancer, and management of under-recognized symptoms in older patients with cancer.

Case report of a patient with chemotherapy-induced peripheral neuropathy treated with manual therapy (massage)

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common, miserable, potentially severe, and often dose-limiting side effect of several first and second-line anti-cancer agents with little in the way of effective, acceptable treatment. Although mechanisms of damage differ, manual therapy (therapeutic massage) has effectively reduced symptoms and improved quality of life in patients with diabetic peripheral neuropathy.

METHODS

Here, we describe application of manual therapy (techniques of effleurage and petrissage) to the extremities in a patient with grade 2 CIPN subsequent to prior treatment with docetaxel and cisplatin for stage III esophageal adenocarcinoma. Superficial cutaneous temperature was monitored using infrared thermistry as proxy for microvascular blood flow.

RESULTS

By the end of the course of manual therapy without any change in medications, CIPN symptoms were greatly reduced to grade 1, with corresponding improvement in quality of life. Improvements in superficial temperature were observed in fingers and toes.

CONCLUSIONS

Manual therapy was associated with almost complete resolution of the tingling and numbness and pain of CIPN in this patient. Concurrently increased superficial temperature suggests improvements in CIPN symptoms may have involved changes in blood circulation. To our knowledge, this is the first report of using manual therapy for amelioration of CIPN.

The management of cancer pain

The experience of pain in cancer is widely accepted as a major threat to quality of life, and the relief of pain has emerged as a priority in oncology care. Pain is associated with both the disease as well as treatment, and management is essential from the onset of early disease through long-term survivorship or end-of-life care. Effective relief of pain is contingent upon a comprehensive assessment to identify physical, psychological, social, and spiritual aspects and as a foundation for multidisciplinary interventions. Fortunately, advances in pain treatment and in the field of palliative care have provided effective treatments encompassing pharmacological, cognitive-behavioral, and other approaches. The field of palliative care has emphasized that attention to symptoms such as pain is integral to quality cancer care.