Debilitating musculoskeletal pain and stiffness with letrozole and exemestane: associated tenosynovial changes on magnetic resonance imaging

A qualitative exploration of the impact of yoga on breast cancer survivors with aromatase inhibitor-associated arthralgias

RESEARCH QUESTION

Arthralgia affects postmenopausal breast cancer survivors (BCS) receiving aromatase inhibitors (AI), which may result in reduced function and long-term well-being. This is an exploratory, qualitative investigation of BCS who participated in a yoga-based program to understand impact on joint pain and various aspects of quality of life (QOL) through a yoga program.

THEORETICAL FRAMEWORK

Social cognitive theory was used and provided the foundation for developing a yoga intervention through sources of efficacy information: (1) performance accomplishment, (2) structured experience, (3) verbal support from instructor and group, and (4) physical feedback.

METHODOLOGY

Ten postmenopausal women with stage I-III breast cancer and AI associated arthralgia (AIAA) received yoga twice a week for eight weeks for 90 minutes and were instructed to continue in a home-based yoga program. We used social cognitive theory (SCT) to structure a yoga intervention as an ongoing physical activity to manage joint pain and function. Participants completed journal reflections on their experience and received weekly phone calls.

ANALYSIS

Data was collected and analyzed using qualitative methods. Member checks were completed and emergent themes were explored and agreed upon by the research team to ensure reliability and validity of data. Several emergent themes were discovered: Empowerment: Importance of Camaraderie, Community, and Sharing; Pain Relief; Increased Physical Fitness (Energy, Flexibility, and Function); Relieved Stress/Anxiety and Transferability of Yoga through Breathing. These themes were identified through instructor observation, participant observation, and weekly phone call documentation.

INTERPRETATION

Participants experienced an eight-week yoga intervention as an effective physical activity and support group that fostered various improvements in quality of life (QOL) and reduction in AIAA. Participants were highly motivated to improve physical fitness levels and reduce pain. This study revealed benefits from alternative forms of exercise such as yoga to provide a structure, which is transferable in other situations. Information, structured physical guidance in yoga postures, support, and feedback are necessary to foster physical activity for BCS experiencing pain.

IMPLICATIONS FOR CANCER SURVIVORS

Results of this qualitative analysis indicate that interventions to support BCS with AIAA are warranted. Yoga appears to positively impact these side effects of hormonal therapies. Additional research would aid in the development of other interventions.

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.

Rheumatic complaints in women taking aromatase inhibitors for treatment of hormone-dependent breast cancer

BACKGROUND

The rheumatic adverse effects accompanying treatment with aromatase inhibitors (AIs) in hormone-dependent breast cancer represent an area of clinical relevance and emerging concern. This report describes these rheumatic complaints detailing their clinical pattern.

METHODS

During 1-year period, 18 consecutive postmenopausal women (mean age, 58.33 years; range, 52-66 years) in treatment with AIs for hormone-dependent breast cancer (mean duration of therapy, 12.0 months; range, 9.1-17.7 months) were referred for evaluation in the outpatient clinic of the rheumatology unit in relation to rheumatic complaints. According to a routine protocol planned with oncologists, patient evaluations consisted of a complete clinical examination with careful assessment of rheumatic complaints and related physical symptoms, followed by laboratory testing and a bone scintiscan. In no cases were rheumatic complaints present before AI therapy.

RESULTS

On the basis of clinical data and investigations and by applying accepted diagnostic criteria, a diagnosis of an undifferentiated spondyloarthropathy was reached in 10 (55.5%) of the 18 patients studied, and an oligoarthritis was shown in 2 more patients (11.1%), whereas a simple arthralgia was found in the remaining 6 patients (33.3%). In the patients meeting criteria as belonging to a spondyloarthritic subset, a family history positive for psoriasis and celiac disease was shown in 2 and 1 instance, respectively, whereas HLA-CW6 and HLA-B27 were detected in 3 and 1 case. A high serum level of anti-cyclic citrullinated peptide antibodies was shown in 1 patient with oligoarthritis. Most of the patients (16/18) were treated with nonsteroidal anti-inflammatory drugs or with corticosteroids. Methotrexate (10 mg weekly) was added in 3 of these patients, nonresponders. Aromatase inhibitor discontinuation was needed in the remaining 2 cases with spontaneous resolution of symptoms over time.

CONCLUSIONS

Data from the present study emphasize a previously unsuspected high prevalence of defined arthritides underlying these rheumatic complaints. Therefore, investigative efforts should be addressed to better clarify the clinical and pathogenetic significance of these important consequences of AI therapy. An accurate monitoring of rheumatic complaints has to be suggested to patients taking AI therapy, with a rapid referral to a rheumatologist in the case of consistent suspicion of an inflammatory arthritis.

A prospective pilot study investigating the musculoskeletal pain in postmenopausal breast cancer patients receiving aromatase inhibitor therapy

BACKGROUND

Although arthralgia is a known adverse effect of aromatase inhibitor (ai) treatment in postmenopausal breast cancer patients, few studies have carried out a comprehensive evaluation of the nature, onset, and incidence of musculoskeletal (msk) pain in these patients. We therefore used a pilot study to identify conditions or markers predictive of pain.

METHODS

For 24 weeks, we monitored 30 eligible postmenopausal women starting ai therapy. Pre-existing and incident msk conditions and pain were assessed clinically and with ultrasonography of the hands and wrists. In addition, patient questionnaires were used to assess pain before and during ai therapy. Biochemical markers were measured at baseline and at regular intervals after anastrozole therapy began. Gene profiling studies were carried out before and 48 hours after the initial ai administration.

RESULTS

Over the 24-week study period, 20 participants (67%) showed no pain symptoms; 5 (17%) experienced low or moderate pain at baseline, which did not increase with ai treatment; and during therapy, 5 (17%) showed exacerbation of pain attributable to osteoarthritis of the hand and to finger flexor tenosynovitis. Although all 30 participants had some degree of msk conditions before anastrozole therapy started, the pre-existing conditions did not necessarily predispose the women to increased pain during anastrozole treatment. Higher levels of urinary N-telopeptides of type i collagen were associated with the groups presenting pain, suggesting a higher extent of pre-existing bone resorption, without significant evolution over the 24-week treatment period. Slightly higher levels of 1,25(OH)(2) vitamin D(3) were observed at baseline in patients with pain increase, but did not significantly change during treatment; however, average levels of 25(OH) vitamin D(3) increased, likely because of supplementation. Although biochemical markers did not discriminate efficiently between pain groups, a signature of 166 genes in peripheral blood mononuclear cells was identified that could stratify patients into the various groups observed in this pilot study. The gene signature was enriched in components of inflammatory signalling and chemokine expression, of antitumoural immunity pathways, and of metabolic response to hormones and xenobiotics, although no clinically significant association could be made in the present study, considering the small number of patients. Nevertheless, the observed trend suggests the feasibility of developing surrogate predictive markers of msk pain. Patient compliance was high in this study and was not affected by pain exacerbation.

CONCLUSIONS

Baseline msk assessment showed pre-existing causes for pain in most of the study patients before initiation of the ai. Exacerbation of existing osteoarthritis pain and tenosynovial symptoms was the primary cause of pain increase. Musculoskeletal pain assessment at baseline and prompt treatment of pain symptoms may help to optimize adherence to ai therapy. The value of routinely assessing inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate was not supported by our pilot study. Gene expression profiles in peripheral blood mononuclear cells may be further explored in larger-scale studies as stratification markers to identify patients at risk of developing arthralgia.

The CIRAS study: a case control study to define the clinical, immunologic, and radiographic features of aromatase inhibitor-induced musculoskeletal symptoms

Aromatase inhibitors (AIs) are widely prescribed for post-menopausal hormone receptor-positive breast cancer; however, musculoskeletal symptoms limit their tolerability. The purpose of this study was to determine whether joint pain in women receiving AIs is associated with inflammatory arthritis as measured by the disease activity score-28 (DAS-28), and to evaluate association with tenosynovitis on ultrasound. A total of 48 postmenopausal women with stage I-III breast cancer and hand pain were recruited from the Lombardi Comprehensive Cancer Center. Those receiving AIs were cases (n = 25), and those not receiving AIs were controls (n = 23). During a single study visit, subjects underwent blinded rheumatologic evaluation, DAS-28, health assessment questionnaires, autoantibodies, inflammatory markers, hand X-ray, and hand Duplex ultrasound. There were no significant differences between cases and controls in DAS-28, or inflammatory markers. A positive ANA (titer > 1:160) was found in ten patients, four of whom met criteria for autoimmune disease (two with rheumatoid arthritis and two with Sjogren's syndrome, equally distributed among cases and controls). This highlights the importance of considering underlying autoimmune disease in subjects with musculoskeletal complaints. Morning stiffness was more prolonged in women receiving AIs, but this did not reach statistical significance (P = 0.07). Ultrasound evidence of flexor tenosynovitis was common in both groups. Although tenosynovitis was not correlated with AI use (P = 0.26), there was a trend toward an association between tenosynovitis and morning stiffness (P = 0.089). While aromatase inhibitor-induced musculoskeletal symptoms (AIMSS) were more common in subjects receiving AIs, they were not unique to AI users. There was no association between presence of AIMSS features and other chemotherapy or medication exposures. Although the majority of subjects had been using AIs for more than 6 months, this study did not find evidence for inflammatory arthritis in women with hand pain receiving AIs. Further studies are needed to develop a case definition of AIMSS, and to confirm whether these symptoms are attributable to AI use.

Impact of yoga on functional outcomes in breast cancer survivors with aromatase inhibitor-associated arthralgias

Arthralgia affects postmenopausal breast cancer survivors (BCSs) receiving aromatase inhibitors (AIs). This study aims to establish the feasibility of studying the impact of yoga on objective functional outcomes, pain, and health-related quality of life (HR-QOL) for AI-associated arthralgia (AIAA). Postmenopausal women with stage I to III breast cancer who reported AIAA were enrolled in a single-arm pilot trial. A yoga program was provided twice a week for 8 weeks. The Functional Reach (FR) and Sit and Reach (SR) were evaluated as primary outcomes. Pain, as measured by the Brief Pain Inventory (BPI), self-reported Patient Specific Functional Scale (PSFS), and Functional Assessment of Cancer Therapy-Breast (FACT-B) were secondary outcomes. Paired t tests were used for analysis, and 90% provided data for assessment at the end of the intervention. Participants experienced significant improvement in balance, as measured by FR, and flexibility, as measured by SR. The PSFS improved from 4.55 to 7.21, and HR-QOL measured by FACT-B also improved; both P < .05. The score for the Pain Severity subscale of the BPI reduced. No adverse events nor development or worsening of lymphedema was observed. In all, 80% of participants adhered to the home program. Preliminary data suggest that yoga may reduce pain and improve balance and flexibility in BCSs with AIAA. A randomized controlled trial is needed to establish the definitive efficacy of yoga for objective functional improvement in BCSs related to AIAA.

Pharmacology of arthralgia with estrogen deprivation

BACKGROUND

The third generation aromatase inhibitors (AIs) have become an established component of postmenopausal estrogen receptor positive breast cancer therapy. Unfortunately, up to half of AI-users experience the AI-induced musculoskeletal syndrome (AIMSS) (arthralgia, carpal tunnel syndrome, start pains, stiffness, etc.), which can severely impact quality of life and treatment compliance. We have previously demonstrated that loss of hand grip strength is part of AIMSS and involves tenosynovial changes and fluid retention in joints.

REVIEW OF LITERATURE AND HYPOTHESIS GENERATING FINDINGS

Our presentation during this AI-symposium focuses on available literature regarding AIMSS with new data from a prospective study generating a hypothesis for its pathogenesis. Profound estrogen deprivation as a consequence of AI-use is thought to be the underlying reason but the exact pathway remains unknown. A potential hypothesis is that the growth hormone/insulin like growth factor-I (GH/IGF-I) pathway may be involved. This possibility is based on the non-linear association between body mass index (BMI) and loss of hand grip strength that we observed. It appears that in lean and overweight women, hand grip strength decreases most following intake of an AI. This observation suggests an underlying biological process which probably evolves through the GH/IGF-I pathway, controlled by sex steroids.

CONCLUSION

Estrogen deprivation leads to incapacitating AIMSS and hampers treatment compliance. In our search for the missing link between 'lowering postmenopausal estrogens' and 'arthralgia' we here report on AI-induced changes in grip strength by BMI which we believe are hypothesis generating for an effect of AIs on the GH/IGF-I axis. This needs to be explored prospectively.

Anastrozole

IMPORTANCE OF THE FIELD

Anastrozole is a third-generation aromatase inhibitor used in the adjuvant setting for the treatment of hormone receptor-positive breast cancer. Several adjuvant randomized trials have reported greater efficacy for anastrozole when compared to tamoxifen.

AREAS COVERED IN THIS REVIEW

This review discusses the mechanism of action of anastrozole; pharmacokinetic and pharmacodynamic characteristics; results of randomized controlled trials of anastrozole compared to tamoxifen in the adjuvant treatment of postmenopausal women with hormone receptor-positive breast cancer and the safety profile of anastrozole compared to tamoxifen.

WHAT THE READER WILL GAIN

The reader will gain an understanding of the basic pharmacology of anastrozole, efficacy data from clinical trials comparing anastrozole to tamoxifen, safety profile of anastrozole and ongoing areas of research.

TAKE HOME MESSAGE

The adverse effects of anastrozole.

Aromatase inhibitor-associated bone and musculoskeletal effects: new evidence defining etiology and strategies for management

Aromatase inhibitors are widely used as adjuvant therapy in postmenopausal women with hormone receptor-positive breast cancer. While the agents are associated with slightly improved survival outcomes when compared to tamoxifen alone, bone and musculoskeletal side effects are substantial and often lead to discontinuation of therapy. Ideally, the symptoms should be prevented or adequately treated. This review will focus on bone and musculoskeletal side effects of aromatase inhibitors, including osteoporosis, fractures, and arthralgias. Recent advances have been made in identifying potential mechanisms underlying these effects. Adequate management of symptoms may enhance patient adherence to therapy, thereby improving breast cancer-related outcomes.

Aromatase inhibitor-induced loss of grip strength is body mass index dependent: hypothesis-generating findings for its pathogenesis

BACKGROUND

Our preliminary results showed that tenosynovial changes and decrease in grip strength are associated with the aromatase inhibitor-induced musculoskeletal syndrome (AIMSS). Here, we report the final results and assess the relationship between grip strength and body mass index (BMI).

PATIENTS AND METHODS

We conducted a prospective study including postmenopausal early breast cancer patients receiving either an aromatase inhibitor (AI) or tamoxifen. Primary end point was change from baseline in tenosynovial abnormalities. Secondary end points were changes from baseline in morning stiffness, intra-articular fluid and grip strength and its association with BMI.

RESULTS

After 6 months of therapy, 74% [95% confidence interval (CI) 51% to 89%] of AI-treated patients had worsened tenosynovial abnormalities, 56% (95% CI 34% to 75%) had increased intra-articular fluid, and 22% (95% CI 9% to 45%) had increased morning stiffness. Grip strength decreased 8% for the left hand (95% CI 2% to 21%) and 11% for the right (95% CI 4% to 17%). Regression analysis suggested that grip strength decreased more for subjects with high or with low BMI.

CONCLUSIONS

AIMSS is characterized by tenosynovial changes, intra-articular fluid and morning stiffness. We hypothesize that the quadratic association between BMI and loss of grip strength reflects AI-induced changes on the endocrine control of the growth hormone insulin-like growth factor-I pathway.

A prospective study of aromatase inhibitor-associated musculoskeletal symptoms and abnormalities on serial high-resolution wrist ultrasonography

BACKGROUND

Nearly half of women treated with aromatase inhibitors (AI) develop AI-associated musculoskeletal symptoms (AIMSS) such as arthralgias, but to the authors' knowledge the etiology is unclear. The upper extremities are frequently affected, especially the wrists, hands, and fingers. AI use may also increase the risk of developing carpal tunnel syndrome. Tendon sheath fluid and tenosynovial changes have been demonstrated by imaging symptomatic patients who were treated with AIs. The authors hypothesized that these abnormalities are correlated with AIMSS.

METHODS

Thirty consecutive patients in whom adjuvant therapy with letrozole or exemestane was initiated on a prospective clinical trial enrolled in a pilot study evaluating tendon and joint abnormalities at baseline and after 3 months of AI therapy. Patients underwent high-resolution ultrasonography of the wrists bilaterally and completed the Health Assessment Questionnaire (HAQ) and pain Visual Analog Scale (VAS). AIMSS were defined as an increase in the HAQ or VAS score during AI therapy that exceeded a predefined cutoff.

RESULTS

Twenty-five patients completed both the baseline and 3-month assessments. During the first 12 months of AI therapy, 15 patients developed AIMSS, and 13 discontinued therapy because of musculoskeletal symptoms. There was a trend toward an association between the presence of tendon sheath abnormalities on wrist ultrasound at baseline and the development of AIMSS (P = .06).

CONCLUSIONS

Clinically relevant musculoskeletal symptoms develop in women treated with AIs, leading to treatment discontinuation in a substantial percentage of these patients. However, in the current study, patient-reported symptoms were not found to be associated with changes visible on wrist ultrasonography.

Vitamin D receptor and enzyme expression in dorsal root ganglia of adult female rats: modulation by ovarian hormones

Vitamin D insufficiency impacts sensory processes including pain and proprioception, but little is known regarding vitamin D signaling in adult sensory neurons. We analyzed female rat dorsal root ganglia (DRG) for vitamin receptor (VDR) and the vitamin D metabolizing enzymes CYP27B1 and CYP24. Western blots and immunofluorescence revealed the presence of these proteins in sensory neurons. Nuclear VDR immunoreactivity was present within nearly all neurons, while cytoplasmic VDR was found preferentially in unmyelinated calcitonin gene-related peptide (CGRP)-positive neurons, colocalizing with CYP27B1 and CYP24. These data suggest that 1,25(OH)(2)D3 may affect sensory neurons through nuclear or extranuclear signaling pathways. In addition, local vitamin D metabolite concentrations in unmyelinated sensory neurons may be controlled through expression of CYP27B1 and CYP24. Because vitamin D deficiency appears to exacerbate some peri-menopausal pain syndromes, we assessed the effect of ovariectomy on vitamin D-related proteins. Two weeks following ovariectomy, total VDR expression in DRG dropped significantly, owing to a slight decrease in the percentage of total neurons expressing nuclear VDR and a large drop in unmyelinated CGRP-positive neurons expressing cytoplasmic VDR. Total CYP27B1 expression dropped significantly, predominantly due to decreased expression within unmyelinated CGRP-positive neurons. CYP24 expression remained unchanged. Therefore, unmyelinated CGRP-positive neurons appear to have a distinct vitamin D phenotype with hormonally-regulated ligand and receptor levels. These findings imply that vitamin D signaling may play a specialized role in a neural cell population that is primarily nociceptive.

Musculoskeletal adverse events associated with adjuvant aromatase inhibitors

Musculoskeletal symptoms including arthralgia and myalgia occur frequently in aging women, particularly during the transition to menopause, when plasma estrogens precipitously decline. In postmenopausal women (PMW) with breast cancer, third-generation aromatase inhibitors (AIs) as adjuvant hormonal therapy have proven to be more effective, and to have a more predictable side effect profile, than tamoxifen. However, AIs further reduce plasma estrogens in PMW, exacerbating musculoskeletal symptoms. Clinical trial data have shown significantly higher incidences of arthralgia and myalgia with AIs compared with women on tamoxifen or placebo. Symptoms may be severe enough to significantly affect quality of life; musculoskeletal symptoms are a frequent reason for discontinuing therapy. In many cases, symptoms can be effectively managed with oral analgesics or other strategies. Early recognition and effective management of musculoskeletal symptoms can help maximize treatment compliance, enabling patients to derive optimal benefit from therapy in terms of preventing recurrence.

Rheumatic disorders and functional disability with aromatase inhibitor therapy

BACKGROUND

Aromatase inhibitor therapy is often effective for breast cancer, yet it can be accompanied by musculoskeletal pain and stiffness. This prevalence assessment aimed to characterize a rheumatologist's view of frequency and clinical features, including associated disability, within a breast cancer clinic panel of 77 patients.

PATIENTS AND METHODS

The "aromatase inhibitor arthralgia" frequency was estimated at 50%, including both those with new and worsened discomfort. Substantial functional disability was associated, whether measured by individual functional disability (frequencies ranging from 39% to 61%) or composite score of 7 functional disability areas (median score 5 compared with median 0 in the comparison group; P = .00003).

RESULTS

The frequency of clinical hand osteoarthritis appeared somewhat increased in the aromatase inhibitor arthralgia group (28% vs. 14%; not statistically significant). Yet the distribution of aromatase inhibitor-related symptoms and functional disabilities appeared to parallel those joint regions commonly affected by osteoarthritis. Using clinical criteria to assess 5 common rheumatic disorders (hand osteoarthritis, trigger finger, carpal tunnel syndrome, Raynaud's phenomenon, and sicca syndrome), the aromatase inhibitor arthralgia group tended to have more common rheumatic disorders (P < .05), consistent with nociceptive mechanisms making latent disorders symptomatic.

CONCLUSION

Aromatase inhibitor therapy for postmenopausal breast cancer might be associated with common musculoskeletal symptoms and with substantial functional disability and should prompt patient education. In view of the potential relevance of estrogen deprivation to osteoarthritis onset and severity, future studies of natural history should include systematic assessment of osteoarthritis frequency and severity.

Aromatase inhibitor-induced arthralgia in early breast cancer: what do we know and how can we find out more?

Aromatase inhibitors (AIs) are a standard of care for the adjuvant treatment of hormone responsive early carcinoma of the breast as demonstrated in a number of large international phase III randomised trials. Arthralgia was a somewhat unexpected side effect of this class of agents and has proven to be potentially problematic in clinical practice. Although rates of up 35% have been reported in the randomised trials, the figure has been much higher in subsequent case series. There is concern that these symptoms are significant and may affect compliance and thus the overall efficacy of treatment. It is therefore extremely important that we evaluate this syndrome with a view to gaining more information regarding its clinical features and possible aetiological mechanism. The potential aetiological mechanisms and evidence for aromatase inhibitor-induced arthralgia (AIA) are reviewed in this article. Looking forward, it is now important that prospective clinical trials are well designed to evaluate this syndrome and potential therapeutic strategies to circumvent it. Radiological imaging and biochemical analyses may help our understanding of AIA and these are discussed.

Feasibility trial of electroacupuncture for aromatase inhibitor--related arthralgia in breast cancer survivors

BACKGROUND

Arthralgia affects postmenopausal women receiving aromatase inhibitors (AIs) for breast cancer. Given the existing evidence for electroacupuncture (EA) for treatment of osteoarthritis in the general population, this study aims to establish the feasibility of studying EA for treating AI-related arthralgia.

PATIENTS AND METHODS

Postmenopausal women with stage I-III breast cancer who reported AI-related arthralgia were enrolled in a single-arm feasibility trial. EA was provided twice a week for 2 weeks followed by 6 weekly treatments. The protocol was based on Chinese medicine diagnosis of "Bi" syndrome with electrostimulation of needles around the painful joint(s). Pain severity of the modified Brief Pain Inventory was used as the primary outcome. Joint stiffness, joint interference, and Patient Global Impression of Change (PGIC) were secondary outcomes. Paired t tests were used for analysis.

RESULTS

Twelve women were enrolled and all provided data for analysis. From baseline to the end of intervention, patients reported reduction in pain severity (from 5.3 to 1.9), stiffness (from 6.9 to 2.4), and joint symptom interference (from 4.7 to 0.8), all P < .001; 11/12 considered joint symptoms "very much better" based on the PGIC. Subjects also reported significant decrease in fatigue (from 4.4 to 1.9, P = .005) and anxiety (from 7.1 to 4.8, P = .01). No infection or development or worsening of lymphedema was observed.

CONCLUSION

Preliminary data establish the feasibility of recruitment and acceptance as well as promising preliminary safety and effectiveness. A randomized controlled trial is warranted to establish the efficacy of EA for AI-related arthralgia in breast cancer survivors.

Arthralgia in 329 Patients Taking Aromatase Inhibitors

Background

Arthralgia is common in post-menopausal women taking aromatase inhibitors. However, the underlying mechanism remains unknown.

Patients and Methods

We retrospectively examined the records of outpatients taking aromatase inhibitors to ascertain the frequency and severity of arthralgia.

Results

Among 329 patients taking aromatase inhibitors (anastrozole in 239 and exemestane in 90 patients), 27% had arthralgia. There were 51 patients (16%) who switched from one aromatase inhibitor to another or quit aromatase inhibitor treatment. Arthralgia was the second most common reason for treatment changes in these 51 cases. In most cases, symptoms resolved after switching to a selective estrogen receptor modulator (SERM). We examined the relationships of arthralgia with other factors such as age, type of medication, prior treatments, and bone density. The arthralgia rate was significantly lower (p < 0.05) in patients with preceding endocrine therapy. No significant difference was detected between patients with versus patients without chemotherapy. Furthermore, there was no relationship between bone density and arthralgia.

Conclusion

Our observations suggest SERM treatment combined with an aromatase inhibitor to be perhaps the most practical clinical solution to the problem of arthralgia.

Aromatase inhibitor-induced carpal tunnel syndrome: results from the ATAC trial

PURPOSE

Carpal tunnel syndrome (CTS) is a condition in which the median nerve is compressed, leading to pain and muscle weakness in the fingers and hand. Aromatase inhibitors lead to profound estrogen suppression and may be expected to increase the risk of CTS in postmenopausal women receiving adjuvant therapy for early breast cancer.

PATIENTS AND METHODS

The current analyses were based on the 100-month median follow-up data in postmenopausal women in the two monotherapy arms (anastrozole, n = 3,092; tamoxifen, n = 3,094). Here, we investigate the natural history of patients who presented with CTS during adjuvant treatment for breast cancer and the relative importance of a range of known risk factors for CTS.

RESULTS

After 100 months of follow-up, 80 cases (2.6%) of CTS were reported in the anastrozole arm, compared with 23 cases (0.7%) in the tamoxifen arm (P < .0001). The majority of CTS cases were reported as mild to moderate intensity and occurred early. None of the women stopped treatment medication as a result of CTS. CTS was significantly increased for women who used prior hormone replacement therapy (P = .007) or received prior chemotherapy (P = .01). Those who were 60 years of age or older at entry were at lower risk of CTS compared with their counterparts (P = .002).

CONCLUSION

Although the use of anastrozole is associated with a greater incidence of CTS, it is rare, and most cases were of mild to moderate intensity and short duration. CTS has little impact on the overall risk-to-benefit ratio for the use of anastrozole in postmenopausal women with early breast cancer.

Prospective study to assess short-term intra-articular and tenosynovial changes in the aromatase inhibitor-associated arthralgia syndrome

PURPOSE

Arthralgia is an adverse class effect of aromatase inhibitors (AIs). To date, its exact mechanism remains unclear. The purpose of this study was to investigate the changes in clinical rheumatologic features and magnetic resonance imaging (MRI) of hands and wrists in AI and tamoxifen users.

PATIENTS AND METHODS

This is a prospective single-center study including 17 consecutive postmenopausal patients with early breast cancer receiving either tamoxifen (n = 5) or an AI (n = 12). At baseline and after 6 months, patients filled in a rheumatologic history questionnaire and a rheumatologic examination including a grip strength test was done. At the same time points, MRI of both hands and wrists was performed. The primary end point was tenosynovial changes from baseline on MRI. Secondary end points were changes from baseline for morning stiffness, grip strength, and intra-articular fluid on MRI. Wilcoxon signed ranks was used to test changes from baseline and the Spearman correlation coefficient to assess the association between rheumatologic and MRI changes from baseline.

RESULTS

At 6 months, patients on AI had a decrease in grip strength (P = .0049) and an increase in tenosynovial changes (P = .0010). The decrease in grip strength correlated well with the tenosynovial changes on MRI (P = .0074). Only minor changes were seen in patients on tamoxifen. AI users reported worsening of morning stiffness and showed an increase in intra-articular fluid on MRI.

CONCLUSION

The functional impairment of hands in the AI-associated arthralgia syndrome is characterized by tenosynovial changes on MRI correlating with a significant decrease in hand grip strength.

Aromatase inhibitors and musculoskeletal symptoms

AIMS

Recent evidence shows aromatase inhibitors (AIs) to be of benefit over tamoxifen in the adjuvant setting. It is also apparent that musculoskeletal symptoms associated with AIs may be a significant problem in the clinical setting. The aim of this article is to review the data on AIs with respect to musculoskeletal symptoms in the adjuvant setting.

MATERIAL AND METHODS

A review on the literature relating to AIs in the adjuvant setting and musculoskeletal symptoms.

RESULTS

Results of phase III trials show lower incidence of musculoskeletal symptoms than reported in the clinical setting.

DISCUSSION

AIs offer a significant advantage over tamoxifen. More research is required to ascertain the cause and to define the spectrum of musculoskeletal symptoms reported in women taking AIs. Decision of appropriate treatment should be made jointly between clinician and patient after full discussion of the risks and benefits.

Exemestane's 17-hydroxylated metabolite exerts biological effects as an androgen

Aromatase inhibitors (AI) are being evaluated as long-term adjuvant therapies and chemopreventives in breast cancer. However, there are concerns about bone mineral density loss in an estrogen-free environment. Unlike nonsteroidal AIs, the steroidal AI exemestane may exert beneficial effects on bone through its primary metabolite 17-hydroexemestane. We investigated 17-hydroexemestane and observed it bound estrogen receptor alpha (ERalpha) very weakly and androgen receptor (AR) strongly. Next, we evaluated 17-hydroexemestane in MCF-7 and T47D breast cancer cells and attributed dependency of its effects on ER or AR using the antiestrogen fulvestrant or the antiandrogen bicalutamide. 17-Hydroexemestane induced proliferation, stimulated cell cycle progression and regulated transcription at high sub-micromolar and micromolar concentrations through ER in both cell lines, but through AR at low nanomolar concentrations selectively in T47D cells. Responses of each cell type to high and low concentrations of the non-aromatizable synthetic androgen R1881 paralleled those of 17-hydroexemestane. 17-Hydroexemestane down-regulated ERalpha protein levels at high concentrations in a cell type-specific manner similarly as 17beta-estradiol, and increased AR protein accumulation at low concentrations in both cell types similarly as R1881. Computer docking indicated that the 17beta-OH group of 17-hydroexemestane relative to the 17-keto group of exemestane contributed significantly more intermolecular interaction energy toward binding AR than ERalpha. Molecular modeling also indicated that 17-hydroexemestane interacted with ERalpha and AR through selective recognition motifs employed by 17beta-estradiol and R1881, respectively. We conclude that 17-hydroexemestane exerts biological effects as an androgen. These results may have important implications for long-term maintenance of patients with AIs.

Prospective characterization of musculoskeletal symptoms in early stage breast cancer patients treated with aromatase inhibitors

PURPOSE

Aromatase inhibitors (AIs) are increasingly used as adjuvant treatment of postmenopausal women with hormone receptor-positive breast cancer. AIs are commonly associated with musculoskeletal symptoms. The primary objective of this study was to describe the musculoskeletal symptoms that developed in the first 100 subjects enrolled who had at least 6 months follow-up.

METHODS

Women with early stage hormone receptor-positive breast cancer were recruited into a multicenter randomized clinical trial to study the pharmacogenomics of two AIs, exemestane, and letrozole. Patients completed the Health Assessment Questionnaire (HAQ) and Visual Analog Scale (VAS) at baseline, 1, 3, 6, and 12 months to assess changes in function and pain, respectively. Patients were referred for evaluation by a rheumatologist if their HAQ and/or VAS scores exceeded a predefined threshold.

RESULTS

Forty-four of 97 eligible patients (45.4%) met criteria for rheumatologic referral. Three patients were ineligible because of elevated baseline HAQ (2) and failure to initiate AI therapy (1). No baseline characteristics were significantly associated with referral. Median time to onset of symptoms was 1.6 months (range 0.4-10 months). Clinical and laboratory evaluation of patients evaluated by rheumatology suggested that the majority developed either non-inflammatory musculoskeletal symptoms or inflammation localized to tenosynovial structures. Thirteen patients discontinued AI therapy because of musculoskeletal toxicity after a median 6.1 months (range 2.2-13 months).

CONCLUSIONS

Musculoskeletal side effects were common in AI-treated patients, resulting in therapy discontinuation in more than 10% of patients. There are no identifiable pre-therapy indicators of risk, and the etiology remains elusive.