Aromatase inhibitors associated musculoskeletal disorders and bone fractures in postmenopausal breast cancer patients: a result from Chinese population

Systemic therapies for preventing or treating aromatase inhibitor-induced musculoskeletal symptoms in early breast cancer

BACKGROUND

Adjuvant aromatase inhibitors (AI) improve survival compared to tamoxifen in postmenopausal women with hormone receptor-positive stage I to III breast cancer. In approximately half of these women, AI are associated with aromatase inhibitor-induced musculoskeletal symptoms (AIMSS), often described as symmetrical pain and soreness in the joints, musculoskeletal pain and joint stiffness. AIMSS may have significant and prolonged impact on women's quality of life. AIMSS reduces adherence to AI therapy in up to a half of women, potentially compromising breast cancer outcomes. Differing systemic therapies have been investigated for the prevention and treatment of AIMSS, but the effectiveness of these therapies remains unclear.

OBJECTIVES

To assess the effects of systemic therapies on the prevention or management of AIMSS in women with stage I to III hormone receptor-positive breast cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, WHO International Clinical Trials Registry Platform (ICTRP) and Clinicaltrials.gov registries to September 2020 and the Cochrane Breast Cancer Group (CBCG) Specialised Register to March 2021.  SELECTION CRITERIA: We included all randomised controlled trials that compared systemic therapies to a comparator arm. Systemic therapy interventions included all pharmacological therapies, dietary supplements, and complementary and alternative medicines (CAM). All comparator arms were allowed including placebo or standard of care (or both) with analgesia alone. Published and non-peer-reviewed studies were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies, extracted data, and assessed risk of bias and certainty of the evidence using the GRADE approach. Outcomes assessed were pain, stiffness, grip strength, safety data, discontinuation of AI, health-related quality of life (HRQoL), breast cancer-specific quality of life (BCS-QoL), incidence of AIMSS, breast cancer-specific survival (BCSS) and overall survival (OS). For continuous outcomes, we used vote-counting by reporting how many studies reported a clinically significant benefit within the confidence intervals (CI) of the mean difference (MD) between treatment arms, as determined by the minimal clinically importance difference (MCID) for that outcome scale. For dichotomous outcomes, we reported outcomes as a risk ratio (RR) with 95% CI.

MAIN RESULTS

We included 17 studies with 2034 randomised participants. Four studies assessed systemic therapies for the prevention of AIMSS and 13 studies investigated treatment of AIMSS. Due to the variation in systemic therapy studies, including pharmacological, and CAM, or unavailable data, meta-analysis was limited, and only two trials were combined for meta-analysis. The certainty of evidence for all outcomes was either low or very low certainty. Prevention studies The evidence is very uncertain about the effect of systemic therapies on pain (from baseline to the end of the intervention; 2 studies, 183 women). The two studies, investigating vitamin D and omega-3 fatty acids, showed a treatment effect with 95% CIs that did not include an MCID for pain. Systemic therapies may have little to no effect on grip strength (RR 1.08, 95% CI 0.37 to 3.17; 1 study, 137 women) or on women continuing to take their AI (RR 0.16, 95% 0.01 to 2.99; 1 study, 147 women). The evidence suggests little to no effect on HRQoL and BCS-QoL from baseline to the end of intervention (the same single study; 44 women, both quality of life outcomes showed a treatment effect with 95% CIs that did include an MCID). The evidence is very uncertain for outcomes assessing incidence of AIMSS (RR 0.82, 95% CI 0.63 to 1.06; 2 studies, 240 women) and the safety of systemic therapies (4 studies, 344 women; very low-certainty evidence). One study had a US Food and Drug Administration alert issued for the intervention (cyclo-oxygenase-2 inhibitor) during the study, but there were no serious adverse events in this or any study. There were no data on stiffness, BCSS or OS. Treatment studies The evidence is very uncertain about the effect of systemic therapies on pain from baseline to the end of intervention in the treatment of AIMSS (10 studies, 1099 women). Four studies showed an MCID in pain scores which fell within the 95% CI of the measured effect (vitamin D, bionic tiger bone, Yi Shen Jian Gu granules, calcitonin). Six studies showed a treatment effect with 95% CI that did not include an MCID (vitamin D, testosterone, omega-3 fatty acids, duloxetine, emu oil, cat's claw).  The evidence was very uncertain for the outcomes of change in stiffness (4 studies, 295 women), HRQoL (3 studies, 208 women) and BCS-QoL (2 studies, 147 women) from baseline to the end of intervention. The evidence suggests systemic therapies may have little to no effect on grip strength (1 study, 107 women). The evidence is very uncertain about the safety of systemic therapies (10 studies, 1250 women). There were no grade four/five adverse events reported in any of the studies. The study of duloxetine reported more all-grade adverse events in this treatment group than comparator group. There were no data on the incidence of AIMSS, the number of women continuing to take AI, BCCS or OS from the treatment studies.

AUTHORS' CONCLUSIONS

AIMSS are chronic and complex symptoms with a significant impact on women with early breast cancer taking AI. To date, evidence for safe and effective systemic therapies for prevention or treatment of AIMSS has been minimal. Although this review identified 17 studies with 2034 randomised participants, the review was challenging due to the heterogeneous systemic therapy interventions and study methodologies, and the unavailability of certain trial data. Meta-analysis was thus limited and findings of the review were inconclusive. Further research is recommended into systemic therapy for AIMSS, including high-quality adequately powered RCT, comprehensive descriptions of the intervention/placebo, and robust definitions of the condition and the outcomes being studied.

Symptom Map of Endocrine Therapy for Breast Cancer: A Scoping Review

BACKGROUND

Multiple symptoms associated with endocrine therapy have a detrimental impact on medication adherence and quality of life.

OBJECTIVE

The purpose of this scoping review is to map the symptoms during endocrine therapy for breast cancer to provide implications for current practice and suggestions for future research.

METHODS

The PubMed, CINAHL, and China Science Periodical Databases were searched to identify related studies published in English and Chinese languages. References of included articles were reviewed for additional eligible studies. Of the 2551 articles identified, 57 articles met inclusion criteria and were included in this scoping review.

RESULTS

Evidence for the 16 most studied symptoms and 15 most prevalent symptoms were synthesized. Five key symptoms associated with endocrine therapy were identified, including joint/muscle pain, hot flashes, low sexual interest/desire, joint/muscle stiffness, and fatigue/lack of energy. Rarely studied but highly prevalent symptoms and other gaps in the symptom science during endocrine therapy for breast cancer were identified.

CONCLUSION

Nurses caring for women receiving endocrine therapy for breast cancer should assess the 5 key symptoms identified. There remain substantial gaps in the science related to the symptom experience during endocrine therapy for breast cancer. Future studies should focus on the domains of symptom intensity and distress, specific understudied symptoms, symptom clusters, and development of symptom assessment instruments specific to symptoms associated with endocrine therapy.

IMPLICATIONS FOR PRACTICE

This scoping review identified 5 well-studied and highly prevalent symptoms that should be assessed in women with breast cancer receiving endocrine therapy.

Adjuvant endocrine therapy side-effects among postmenopausal breast cancer patients in Malaysia

OBJECTIVE

This study was conducted to determine the prevalence and severity of menopausal symptoms and their associated risk factors among postmenopausal breast cancer patients receiving adjuvant endocrine therapy.

METHODS

Postmenopausal breast cancer patients on endocrine therapy were recruited at three hospitals in Malaysia. Presence and severity of menopausal symptoms were determined using the Menopause Rating Scale. Sociodemographic and clinical data were collected from medical records.

RESULTS

A total of 192 patients participated in this study. Commonly reported symptoms were musculoskeletal pain (59.9%), physical and mental exhaustion (59.4%), and hot flushes (41.1%). Multivariate analyses indicated that increasing number of years after menopause until the start of endocrine therapy was significantly associated with less likelihood of reporting menopausal symptoms and musculoskeletal pain. Patients with primary or secondary education levels reported significantly less menopausal urogenital symptoms compared to patients with a tertiary education level. Patients using aromatase inhibitors were twice as likely to experience musculoskeletal pain compared to patients using tamoxifen (odds ratio, 2.18; 95% confidence interval, 1.06-4.50; p < 0.05).

CONCLUSION

Menopausal symptoms and musculoskeletal pain are common problems encountered by postmenopausal breast cancer patients receiving adjuvant endocrine therapy and should be closely monitored for successful treatment.

Aromatase inhibitors are associated with a higher fracture risk than tamoxifen: a systematic review and meta-analysis

Background

In this paper, our aim was to systematically evaluate published evidence of bone fracture risk associated with tamoxifen and aromatase inhibitors in women aged 65 and under, and diagnosed with nonmetastatic breast cancer.

Methods

We comprehensively searched MEDLINE, EMBASE and CINAHL databases from January 1997 through May 2015, and reference lists of the selected articles to identify English-language randomized controlled trials and cohort studies of fracture risk. Two independent reviewers screened articles and assessed methodological quality using Risk of Bias assessment for randomized controlled trials and the Newcastle-Ottawa Scale for cohort studies. Fracture risk was estimated as pooled risk ratios using a random-effects model and inverse variance method.

Results

Of 1926 identified articles, 21 independent studies fulfilled our selection criteria. Similar fracture risk was observed in women treated and not treated with tamoxifen [pooled risk ratio (RR) 0.95; 95% confidence interval (CI) 0.84-1.07]. A 35% (95% CI 1.21-1.51) higher fracture risk was observed in the aromatase inhibitor group compared with the tamoxifen group. A 17% (95% CI 1.07-1.28) higher fracture risk was observed in the aromatase inhibitor group than the no aromatase inhibitor group. Compared with the tamoxifen group, aromatase inhibitor-associated fracture risk increased by 33% (pooled RR 1.33; 95% CI 1.21-1.47) during the tamoxifen/aromatase inhibitor treatment period, but did not increase (pooled RR 0.99; 95% CI 0.72-1.37) during the post-tamoxifen/aromatase inhibitor treatment period.

Conclusions

Fracture risk is significantly higher in women treated with aromatase inhibitors, especially during the treatment period. Tamoxifen is not associated with lower fracture risk while tamoxifen could potentially preserve bone mass. Better osteoporosis management programs, especially during the treatment period, are needed for this group of women.

Vertebral fractures among breast cancer survivors in China: a cross-sectional study of prevalence and health services gaps

BACKGROUND

Breast cancer survivors are at high risk for fracture due to cancer treatment-induced bone loss, however, data is scarce regarding the scope of this problem from an epidemiologic and health services perspective among Chinese women with breast cancer.

METHODS

We designed a cross-sectional study comparing prevalence of vertebral fractures among age- and BMI-matched women from two cohorts. Women in the Breast Cancer Survivors cohort were enrolled from a large cancer hospital in Beijing. Eligibility criteria included age 50-70 years, initiation of treatment for breast cancer at least 5 years prior to enrollment, and no history of metabolic bone disease or bone metastases. Data collected included sociodemographic characteristics; fracture-related risk factors, screening and preventive measures; breast cancer history; and thoracolumbar x-ray. The matched comparator group was selected from participants enrolled in the Peking Vertebral Fracture Study, an independent cohort of healthy community-dwelling postmenopausal women from Beijing.

RESULTS

Two hundred breast cancer survivors were enrolled (mean age 57.5 ± 4.9 years), and compared with 200 matched healthy women. Twenty-two (11%) vertebral fractures were identified among breast cancer survivors compared with 7 (3.5%) vertebral fractures in the comparison group, yielding an adjusted odds ratio for vertebral fracture of 4.16 (95%CI 1.69-10.21, p < 0.01). The majority had early stage (85.3%) and estrogen and/or progesterone receptor positive (84.6%) breast cancer. Approximately half of breast cancer survivors reported taking calcium supplements, 6.1% reported taking vitamin D supplements, and only 27% reported having a bone density scan since being diagnosed with breast cancer.

CONCLUSIONS

Despite a four-fold increased odds of prevalent vertebral fracture among Chinese breast cancer survivors in our study, rates of screening for osteoporosis and fracture risk were low reflecting a lack of standardization of care regarding cancer-treatment induced bone loss.

Bone Density Screening in Postmenopausal Women With Early-Stage Breast Cancer Treated With Aromatase Inhibitors

PURPOSE

In postmenopausal women with breast cancer treated with aromatase inhibitors (AIs), most expert panels advise baseline bone mineral density testing with a dual-energy x-ray absorptiometry (DXA) scan repeated every 1 to 2 years. How often this recommendation is followed is unclear.

METHODS

We performed a retrospective analysis of women with stage I to III breast cancer who started AI therapy from January 1, 2008, to December 31, 2010, with follow-up through December 31, 2012, by using the SEER-Medicare database. Selection criteria included AI use for ≥ 6 months and no recent osteoporosis diagnosis or bisphosphonate use. We used multivariable logistic regression to investigate associations between patient characteristics and receipt of a baseline DXA scan. In patients who continued AI treatment, we assessed rates of follow-up scans.

RESULTS

In the sample of 2,409 patients (median age, 74 years), 51.0% received a baseline DXA scan. Demographic characteristics associated with the absence of a baseline DXA scan were older age (85 to 94 years v 67 to 69 years; odds ratio [OR], 0.62; 95% CI, 0.42 to 0.92) and black v white race (OR, 0.68; 95% CI, 0.47 to 0.97). Among patients who underwent a baseline DXA scan and continued AI for 3 years, 28.0% had a repeat DXA scan within 2 years and 65.9% within 3 years. In aggregate, of the 1,164 patients who continued with AI treatment for 3 years, only 34.5% had both a baseline and at least one DXA scan during the 3-year follow-up period.

CONCLUSION

The majority of older Medicare beneficiaries with breast cancer treated with AIs do not undergo appropriate bone mineral density evaluation.

Fracture risk and adjuvant therapies in young breast cancer patients: a population-based study

BACKGROUND

Breast cancer survivors have an increased risk of bone fracture. But the risk among young patients with adjuvant therapies remains unknown. This population-based study is aimed to assess the incidence and risk of fracture among young (age of 20 to 39 years) breast cancer patients who received adjuvant therapies.

METHODS

From January 2001 to December 2007, 5,146 newly diagnosed breast cancer patients were enrolled from the National Health Insurance Research Database (NHIRD) in Taiwan. Patients were observed for a maximum of 6 years to determine the incidence of newly onset fracture. Kaplan Meier and Cox regression analyses were used to evaluate the risk of fracture in young breast cancer patients who received adjuvant treatments.

RESULTS

Of the total 5,146 young (age of 20 to 39 years) breast cancer patients, the Cox multivariate proportional hazards analysis showed that AIs, radiotherapy, and monoclonal antibodies were significantly associated with a high risk of fracture. Moreover, patients who received AIs for more than 180 days had a high hazard ratio (HR) of 1.77 (95% CI = 0.68-4.57), and patients who received more than four radiotherapy visits had a high HR of 2.54 (95% CI = 1.07-6.06). Under the site-specific analysis, young breast cancer patients who received AIs had the highest risk of hip fracture (HR = 8.520, 95% CI = 1.711-42.432, p < 0.04), whereas patients who received radiotherapy had the highest risk of vertebral fracture (HR = 5.512, 95% CI = 1.847-16.451, p < 0.01).

CONCLUSION

Young breast cancer patients who are receiving AIs, radiotherapy or monoclonal antibody need to be more careful for preventing fracture events. Breast cancer treatment plans are suggested to incorporate fracture prevention interventions.