Carpal tunnel syndrome associated with the use of aromatase inhibitors in breast cancer

Anti-cancer therapeutic agents and carpal tunnel syndrome: Clinical, electrodiagnostic, and ultrasound findings in seven patients

INTRODUCTION

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and rarely develops after drug therapy. This study describes the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in seven patients who experienced CTS due to anti-cancer therapeutic agents.

METHODS

All patients underwent EDX testing, and four patients had an US study.

RESULTS

CTS occurred in four patients with aromatase inhibitors, two with immune checkpoint inhibitors, and one with a selective estrogen receptor modulator. The mean duration between initiation of the anti-cancer therapeutic agents and symptom onset was 6 weeks (range: 2-12 weeks). Decreased digit sensation was noted in all patients; wasting and weakness of the abductor pollicis brevis (APB) was observed in three (42.8%) patients. The compound muscle action potentials (CMAP) of the APB and sensory nerve action potentials of the second or third digit could not be recorded in two (28.5%) and four (57.1%) patients, respectively. The needle EMG detected fibrillations and positive sharp waves in the APB in two patients. The motor unit potentials of the APB were decreased with large polyphasics in three (42.8%) patients. Of the four patients who underwent US testing, all had increased cross-sectional area of the median nerve at the carpal tunnel inlet, three (75%) had thenar muscle atrophy, and two (50%) had a loss of fascicular pattern. Three (42.8%) patients underwent a CTR.

CONCLUSIONS

Physicians should be cognizant of the relationship between anti-cancer therapeutic agents and CTS. EDX studies and US play important roles in the diagnostic assessment of such patients.

Aromatase Inhibitor-Induced Carpal Tunnel Syndrome and Stenosing Tenosynovitis: A Systematic Review

BACKGROUND

Although aromatase inhibitors are the first-line treatment in postmenopausal women with hormone receptor-positive breast cancer, there is increasing evidence that they can induce carpal tunnel syndrome and stenosing tenosynovitis. This systematic review summarizes the risk factors, incidence, and management for patients with aromatase inhibitor-induced carpal tunnel syndrome and stenosing tenosynovitis compared to tamoxifen or placebo.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided systematic review of PubMed/MEDLINE, Ovid Embase, and the Cochrane Central Register of Controlled Trials was conducted (to March 19, 2020), supplemented with Google Scholar, Plastic and Reconstructive Surgery, and The Journal of Hand Surgery. Two reviewers independently completed the primary and secondary screens and the quality appraisal.

RESULTS

This study reviewed 577 abstracts and included 19 studies. Risk factors for aromatase inhibitor-induced carpal tunnel syndrome or stenosing tenosynovitis included hormone replacement therapy before trial entry, history of musculoskeletal symptoms, age younger than 60 years, prior chemotherapy, and body mass index greater than 25 kg/m2. The incidence can be increased up to 10 times compared to tamoxifen. Patient discontinuation of aromatase inhibitor treatment because of carpal tunnel syndrome and stenosing tenosynovitis was reported. Nonsurgical management led to complete resolution of carpal tunnel syndrome symptoms in up to 67 percent of cases. Although most aromatase inhibitor-induced stenosing tenosynovitis original studies were low quality, all recommended surgical release for symptom resolution.

CONCLUSIONS

This study provides current knowledge of the associated risk factors, management options, and quality of literature for aromatase inhibitor-induced carpal tunnel syndrome and stenosing tenosynovitis. Early recognition can prevent self-discontinuation of an aromatase inhibitor and long-term sequelae of poorly treated carpal tunnel syndrome and stenosing tenosynovitis.

Drug-Induced Peripheral Neuropathy: Diagnosis and Management

Peripheral neuropathy comes in all shapes and forms and is a disorder which is found in the peripheral nervous system. It can have an acute or chronic onset depending on the multitude of pathophysiologic mechanisms involving different parts of nerve fibers. A systematic approach is highly beneficial when it comes to cost-effective diagnosis. More than 30 causes of peripheral neuropathy exist ranging from systemic and auto-immune diseases, vitamin deficiencies, viral infections, diabetes, etc. One of the major causes of peripheral neuropathy is drug induced disease, which can be split into peripheral neuropathy caused by chemotherapy or by other medications. This review deals with the latest causes of drug induced peripheral neuropathy, the population involved, the findings on physical examination and various workups needed and how to manage each case.

Estrogen decline is a risk factor for paclitaxel-induced peripheral neuropathy: Clinical evidence supported by a preclinical study

We performed clinical retrospective study in female cancer patients and fundamental experiments in mice, in order to clarify risk factors for paclitaxel-induced peripheral neuropathy (PIPN). In the clinical study, 131 of 189 female outpatients with cancer undergoing paclitaxel-based chemotherapy met inclusion criteria. Breast cancer survivors (n = 40) showed significantly higher overall PIPN (grades 1-4) incidence than non-breast cancer survivors (n = 91). Multivariate sub-analyses of breast cancer survivors showed that 57 years of age or older and endocrine therapy before paclitaxel treatment were significantly associated with severe PIPN (grades 2-4). The age limit was also significantly correlated with overall development of severe PIPN. In the preclinical study, female mice subjected to ovariectomy received repeated administration of paclitaxel, and mechanical nociceptive threshold was assessed by von Frey test. Ovariectomy aggravated PIPN in the mice, an effect prevented by repeated treatment with 17β-estradiol. Repeated administration of thrombomodulin alfa (TMα), known to prevent chemotherapy-induced peripheral neuropathy in rats and mice, also prevented the development of PIPN in the ovariectomized mice. Collectively, breast cancer survivors, particularly with postmenopausal estrogen decline and/or undergoing endocrine therapy, are considered a PIPN-prone subpopulation, and may require non-hormonal pharmacological intervention for PIPN in which TMα may serve as a major candidate.

Carpal Tunnel Release Despite Normal Nerve Conduction Studies in Carpal Tunnel Syndrome Patients

PURPOSE

Carpal tunnel syndrome (CTS) is a common entrapment neuropathy, often requiring carpal tunnel release (CTR) surgery. Often, a nerve conduction study (NCS) is performed before CTR; however, there are various reports questioning the sensitivity of NCS, and some patients do undergo CTR despite normal NCS results. We had the following purposes: (1) to report clinical outcome of CTS patients who undergo CTR despite normal NCS, (2) to identify the characteristics and compare those with abnormal NCS patients in terms of basic features and risk factors, and (3) to analyze and compare normal and abnormal NCS results.

MATERIALS AND METHODS

Medical records of 546 CTS (30 normal NCS and 516 abnormal NCS) patients were retrospectively reviewed. Of 30 normal NCS patients, 7 were excluded, leaving 23 patients in the experimental group. We investigated the influence of age, sex, operative arm, and body mass index, as well as medical conditions known to be risk factors for CTS. In normal NCS patients, as a functional score, we investigated Boston carpal tunnel scores before and after CTR. The NCS results were compared in terms of median motor and median sensory testing. In normal NCS patients, NCS data were compared with that of the contralateral nonoperated wrists.

RESULTS

There were 18 women and 5 men in the normal NCS group (mean age 43.7 years). On physical examination, 22 (94.7%) patients showed a positive Tinel test, 19 (82.6%) showed a positive Phalen test, 8 (34.8%) complained of nocturnal paresthesia, and only 1 (4.3%) presented with thenar atrophy. In 19 of 23 patients, the Boston CTS scores showed significant improvement after CTR. Normal NCS patients were significantly younger and significantly heavier and more likely to be a current smoker. In NCS analysis of normal NCS patients, the operated wrists were closer to the reference values than nonoperated wrists.

CONCLUSIONS

Surgeons should evaluate the possibility of other combined lesions before CTR in normal NCS patients. Normal NCS can be present with a CTS diagnosis, especially in younger patients. Nevertheless, CTR after failed conservative management, despite normal NCS, could relieve subjective symptoms and function.

Electrophysiological and phenotypic profiles of taxane-induced neuropathy

OBJECTIVE

To comprehensively describe patient-reported, functional and neurophysiological outcomes to elucidate the phenotypic profile of taxane-induced neuropathy.

METHODS

Taxane-treated patients (n = 47) completed cross-sectional bilateral clinical and sensory assessments and nerve conduction studies. Patients reported symptom severity via Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx13) questionnaire.

RESULTS

Symptoms of neuropathy were reported by 81% of patients. On clinical examination, 62% had 2 or more abnormalities, with 20% indicating significant symptomatic and objective neuropathy. Nerve conduction studies were consistent with a sensory predominant axonal neuropathy. However, features more typical of entrapment neuropathy were also present in > 50%, which were not associated with overall severity of chemotherapy-induced peripheral neuropathy (CIPN) or clinical risk factors.

CONCLUSIONS

There is considerable variation in CIPN phenotypes associated with taxane-treatment. Understanding their clinical associations may assist in identification of patients at risk of severe neurotoxicity. This would enable treatment modification decisions but also limit early cessation of effective anti-cancer treatment in patients with less severe neurological sequelae.

SIGNIFICANCE

Understanding the CIPN phenotype may inform treatment decisions which could impact clinical and survival outcomes.

Prospective evaluation of finger two-point discrimination and carpal tunnel syndrome among women with breast cancer receiving adjuvant aromatase inhibitor therapy

PURPOSE

Aromatase inhibitors (AIs) are associated with musculoskeletal symptoms and risk of developing carpal tunnel syndrome (CTS), which can impair quality of life and prompt treatment discontinuation. The incidence of CTS and clinical utility of diagnostic tests such as 2-point discrimination (2-PD) have not been prospectively examined among women receiving AIs.

METHODS

Postmenopausal women with stage 0-III hormone receptor-positive breast cancer who were enrolled in a randomized clinical trial investigating adjuvant AIs (Exemestane and Letrozole Pharmacogenetics, ELPh) underwent prospective evaluation of 2-PD with the Disc-criminator™ (sliding aesthesiometer) and completed a CTS questionnaire at baseline, 3, 6, and 12 months, following initiation of AI. Changes in mean 2-PD were analyzed with multivariable mixed effects modelling. A p value < 0.05 was considered statistically significant.

RESULTS

Of 100 women who underwent baseline 2-PD testing, CTS was identified by questionnaire in 11% at baseline prior to AI initiation. Prevalence of CTS at any time in the first year was 26%. A significant increase in worst 2-PD score was observed from baseline to 3 months (3.7 mm to 3.9 mm, respectively, p = 0.03) when adjusted for age, prior chemotherapy, randomized treatment assignment, and diabetes. There were no significant differences in treatment discontinuation due to CTS between the arms.

CONCLUSION

For women receiving adjuvant AI, 2-PD scores were significantly worse at 3 months compared to baseline. Studies are required to assess whether change in 2-PD is an adequate objective assessment for CTS with AI therapy. Early diagnosis of CTS may expedite management, improve AI adherence, and enhance breast cancer outcomes.

Endocrine therapy for breast cancer in the primary care setting

The treatment of hormone-positive breast cancer (bca) is a rapidly evolving field. Improvement in the understanding of the mechanisms of action and resistance to anti-hormonal therapy has translated, in the past decade, into multiple practice-changing clinical trials, with the end result of increased survivorship for patients with all stages of hormone-positive cancer. The primary care physician will thus play an increasing role in the routine care, surveillance, and treatment of issues associated with anti-hormonal therapy. The aim of the present review was to provide a focused description of the issues relevant to primary care, while briefly highlighting recent advances in the field of anti-hormonal therapy.

Key Points

■ Hormone-positive bca is the most prevalent form of bca and, compared with the other subtypes, is usually associated with better survival.■ Survivorship has significantly increased for all stages of hormone-positive bca, making the primary care physician a key player in the care of affected patients.■ The two most common classes of anti-hormonal agents used in these patients are selective estrogen receptor modulators and aromatase inhibitors. Each class of medication is associated with signature side effects.■ Within the past decade, multiple novel estrogen receptor blockers (for example, fulvestrant) and agents aimed at circumventing resistance to endocrine therapy [inhibitors of cyclin-dependent kinase 4/6 and of mtor (the mechanistic target of rapamycin)] have gained clinical ground. Understanding their side effects will be increasingly relevant to primary care physicians.■ Multidisciplinary care is always encouraged in the care of cancer patients receiving anti-hormonal therapy.

Referred symptom from myofascial pain syndrome: One of the most important causes of sensory disturbance in breast cancer patients using taxanes

The aim of this retrospective study was to evaluate common causes of upper extremity sensory disturbance in breast cancer patients. Breast cancer patients who received surgery and taxane chemotherapy (CTx) with upper extremity sensory disturbance that began after CTx were included. With comprehensive clinical history, physical examination and electrodiagnostic results, diagnosis for each patient was made. Fifty-two patients were included: 23 (44.2%) were diagnosed with chemotherapy-induced peripheral neuropathy (CIPN), 7 (13.5%) with myofascial pain syndrome (MPS), six (11.5%) with carpal tunnel syndrome (CTS), four (7.7%) with CIPN and MPS, and three (5.8%) with CIPN and CTS. CIPN was more correlated with sensory symptoms at upper and lower extremities, a shorter time from CTx start, and adriamycin and cytoxan (AC) plus paclitaxel, than with AC plus docetaxel and fluorouracil, epirubicin and cyclophosphamide plus taxanes. MPS was correlated with longer duration of CTx and use of hormone therapy. CTS was correlated with wrist trauma history. Patients with CIPN showed similar degrees of pain even after 3 months of treatment, in comparison to the patients with MPS and CTS. When breast cancer patients complain of upper extremity sensory disturbance, various causes, especially referred symptom from MPS, should be considered for effective treatment.

Anastrozole-Induced Carpal Tunnel Syndrome: Results From the International Breast Cancer Intervention Study II Prevention Trial

PURPOSE

Carpal tunnel syndrome (CTS) occurs when the median nerve is compressed at the wrist in the carpal tunnel. It has been suggested that hormonal risk factors may be involved in the pathogenesis of CTS, and a higher incidence of CTS has been reported in randomized clinical trials with aromatase inhibitors (AIs) compared with tamoxifen.

PATIENTS AND METHODS

This was an exploratory analysis of the International Breast Cancer Intervention Study II, a double-blind randomized clinical trial in which women at increased risk of breast cancer were randomly assigned to receive anastrozole or placebo. This is the first report of risk factors for and characteristics of CTS in women taking an AI in a placebo-controlled trial.

RESULTS

Overall, 96 participants with CTS were observed: 65 (3.4%) in the anastrozole arm and 31 (1.6%) in the placebo arm (odds ratio, 2.16 [1.40 to 3.33]; P < .001). Ten participants were reported as having severe CTS, of which eight were taking anastrozole (P = .08). Eighteen women (0.9%) in the anastrozole arm and six women (0.3%) in the placebo arm reported surgical intervention, which was significantly different (odds ratio, 3.06 [1.21 to 7.72], P = .018). Six women discontinued with the allocated treatment because of the onset of CTS. Apart from treatment allocation, a high body mass index and an a prior report of musculoskeletal symptoms after trial entry were the only other risk factors for CTS identified in these postmenopausal women.

CONCLUSIONS

The use of anastrozole was associated with a higher incidence of CTS but few participants required surgery. Further investigations are warranted into the risk factors and treatment of AI-induced CTS.

Neuromuscular issues in systemic disease

The neuromuscular system can be involved in several systemic conditions. Clinical manifestations can appear at onset or throughout the course of the disease process. New investigational methods, including imaging of peripheral nerves, new laboratory tests, and antibodies, are available. In addition to symptomatic therapies, specific treatment options, such as for familial amyloid neuropathy and Fabry's disease, are becoming increasingly available. Pathomechanisms vary depending on the underlying disease process. In addition to metabolic, hormonal, immune, and antibody-mediated mechanisms, in some generalized diseases, genetic causes need to be considered. This review focuses on different aspects of the peripheral nervous system including the nerve roots, plexuses, mononeuropathies and generalized neuropathies, neuromuscular junction disorders, muscle, and autonomic nervous system.

Neurologic complications of chemotherapy and other newer and experimental approaches

Neurologic complications of conventional cytototxic agents as well as those from monoclonal antibodies and targeted therapies are increasingly observed in patients with cancer. The major categories are represented by alkylating agents (platinum compounds, ifosfamide, procarbazine, thiotepa), mitotic spindle inhibitors (vinca alkaloids, taxanes, etoposide, teniposide), proteasome inhibitors (bortezomib), antibiotics, antimetabolites, thalidomide, lenalidomide, topoisomerase inhibitors, interferon-α, hormones, bevacizumab, trastuzumab, and small tyrosine kinase inhibitors. Peripheral neuropathy is a common adverse effect of a number of chemotherapeutic drugs and often represents a critical factor limiting an adequate dose-intensity of chemotherapy. Regarding the central nervous system (CNS), it is vulnerable to many forms of toxicity from chemotherapeutic agents, including encephalopathy syndromes and confusional states, seizures, headache, cerebrovascular complications, visual loss, cerebellar syndromes, and myelopathy. For a given drug, the occurrence of CNS toxicity depends on several factors, including the total dose, route of administration, presence of structural brain lesions, exposure to prior or concurrent irradiation, and interactions with other drugs. However, many of the neurotoxic reactions are rare and idiosyncratic, and remain unpredictable. Several forms of neuroprotection and rehabilitation are being investigated. Last, the so-called "chemobrain" is an emerging issue, as it is a model of a subtle of and long-lasting damage to neuronal structures from some antineoplastic agents.

Aromatase inhibition 2013: clinical state of the art and questions that remain to be solved

Following their successful implementation for the treatment of metastatic breast cancer, the 'third-generation' aromatase inhibitors (anastrozole, letrozole, and exemestane) have now become standard adjuvant endocrine treatment for postmenopausal estrogen receptor-positive breast cancers. These drugs are characterized by potent aromatase inhibition, causing >98% inhibition of estrogen synthesis in vivo. A recent meta-analysis found no difference in anti-tumor efficacy between these three compounds. As of today, aromatase inhibitor monotherapy and sequential treatment using tamoxifen followed by an aromatase inhibitor for a total of 5 years are considered equipotent treatment options. However, current trials are addressing the potential benefit of extending treatment duration beyond 5 years. Regarding side effects, aromatase inhibitors are not found associated with enhanced risk of cardiovascular disease, and enhanced bone loss is prevented by adding bisphosphonates in concert for those at danger of developing osteoporosis. However, arthralgia and carpal tunnel syndrome preclude drug administration among a few patients. While recent findings have questioned the use of aromatase inhibitors among overweight and, in particular, obese patients, this problem seems to focus on premenopausal patients treated with an aromatase inhibitor and an LH-RH analog in concert, questioning the efficacy of LH-RH analogs rather than aromatase inhibitors among overweight patients. Finally, recent findings revealing a benefit from adding the mTOR inhibitor everolimus to endocrine treatment indicate targeted therapy against defined growth factor pathways to be a way forward, by reversing acquired resistance to endocrine therapy.

Peripheral neuropathies from chemotherapeutics and targeted agents: diagnosis, treatment, and prevention

Peripheral neuropathies induced by chemotherapy (CIPN) are an increasingly frequent problem. Contrary to hematologic adverse effects, which can be treated with hematopoetic growth factors, neither prophylaxis nor specific treatment is available, and only symptomatic treatment can be offered. Neurotoxic drugs are becoming a major dose-limiting factor. The epidemiology is still unclear. Several drug-dependent pathogenetic mechanisms exist. CIPN are predominately sensory, length-dependent neuropathies that develop after a typical cumulative dose. Usually, the appearance of CIPN is dose dependent, although in at least 2 drugs (oxaliplatin and taxanes), immediate toxic effects occur. The most frequent substances causing CIPN are platin compounds, vinka alkaloids, taxanes, and bortezomib and thalidomide. The role of synergistic neurotoxicity caused by previously given chemo-therapies and concomitant chemotherapies and the role pre-existent neuropathy on the development of a CIPN is not clear. As the number of long-term cancer survivors increases and a new focus on long-term effects of chemotherapy-induced neuropathies emerge, concepts of rehabilitation need to be implemented to improve the patients' functions and quality of life.

Bilateral de quervain syndrome after aromatase inhibitor administration: a case report and review of the literature

Aromatase inhibitors are widely used as one of the main treatment options of both early and advanced hormone receptor-positive breast cancer in postmenopausal women. Unfortunately, musculoskeletal symptoms are often presented in patients treated with aromatase inhibitors (AIs), and, although the pathogenesis is unknown, postulated mechanisms have been described. Herein, to our knowledge, we present the first report of bilateral De Quervain syndrome related with AIs therapy with a review of the relevant literature.