Switching to anastrozole versus continued tamoxifen treatment of early breast cancer: preliminary results of the Italian Tamoxifen Anastrozole Trial

Oral nano-formulations for endocrine therapy of endometrioid adenocarcinomas

Endometrial cancer is one of the three major malignant tumors of the reproductive system that threaten women's lives and health. The incidence of this disease is on the rise globally. Most cases of endometrial cancer comprise endometrioid adenocarcinomas, whose treatment is challenged by factors such as their high recurrence rate and the need to preserve fertility among young patients. Thus, oral endocrine therapy has become the main treatment modality. The main drugs used in oral endocrine therapy are progestins, selective estrogen receptor antagonists, and aromatase inhibitors. However, their clinical use is hindered by their low solubility and low oral utilization. The rapid development of nanotechnology allows the combination of these drugs with oral nano-formulations to create a good carrier. Such nanocarriers, including nanospheres, nanocapsules, and micelles can protect the drug against clearance and increase the site specificity of drug delivery. This paper reviews the pathogenesis of endometrioid endometrial cancer (EEC) and oral nano-formulations for endocrine therapy.

Prognostic impact of selection criteria of current adjuvant endocrine therapy trials NATALEE and monarchE in postmenopausal HRpos/HER2neg breast cancer patients treated with upfront letrozole

BACKGROUND

The monarchE and NATALEE trials demonstrated the benefit of CDK4/6 inhibitor (CDK4/6i) therapy in adjuvant breast cancer (BC) treatment. Patient selection, based on clinical characteristics, delineated those at high (monarchE) and high/intermediate recurrence risk (NATALEE). This study employed a historical patient cohort to describe the proportion and prognosis of patients eligible for adjuvant CDK4/6i trials.

METHODS

Between 2009 and 2011, 3529 patients were enrolled in the adjuvant PreFace clinical trial (NCT01908556). Eligibility criteria included postmenopausal patients with hormone receptor-positive (HRpos) BC for whom a five-year upfront therapy with letrozole was indicated. Patients were categorized into prognostic groups according to monarchE and NATALEE inclusion criteria, and their invasive disease-free survival (iDFS) and overall survival (OS) were assessed.

RESULTS

Among 2891 HRpos patients, 384 (13.3 %) met the primary monarchE inclusion criteria. The majority (n = 261) qualified due to having ≥ 4 positive lymph nodes. For NATALEE, 915 out of 2886 patients (31.7 %) met the eligibility criteria, with 126 patients (13.7 %) being node-negative. Patients from monarchE with ≥ 4 positive lymph nodes and NATALEE with stage III BC exhibited the poorest prognosis (3-year iDFS rate 0.87). Patients ineligible for the trials demonstrated prognoses similar to the most favorable patient groups within the eligibility criteria.

CONCLUSION

Patient populations eligible for monarchE and NATALEE trials differed. Nearly a third of the postmenopausal HRpos population, previously under upfront letrozole treatment, met the NATALEE prognostic eligibility criteria. As certain eligible groups had a prognosis similar to non-eligible patients, it might be interesting to explore additional patient groups for CDK4/6i therapy.

Osteoporotic fracture risk in women with breast cancer treated with aromatase inhibitors: a health insurance claims database study in Japan

BACKGROUND

Hormone therapy with aromatase inhibitors (AIs) for estrogen receptor-dependent breast cancer may expose patients to an increased osteoporosis risk. This study was performed to estimate fracture risk in women with breast cancer to whom AIs were prescribed in Japan.

METHODS

This retrospective study used data from the Japanese Medical Data Vision database. Women with breast cancer prescribed AIs over a 12-month period were identified and matched to women not prescribed AIs using a propensity score. Fracture rates were estimated by a cumulative incidence function and compared using a cause-specific Cox hazard model. The proportion of women undergoing bone density tests was retrieved.

RESULTS

For all fractures sites combined, cumulative fracture incidence at 10 years was 0.19 [95%CI: 0.16-0.22] in women prescribed AIs and 0.18 [95%CI: 0.15-0.21] without AIs. AI prescription was not associated with any changes in risk (adjusted hazard ratio: 1.08 [95%CI: 0.99-1.17] p = 0.08). Women prescribed AI more frequently underwent bone density testing (31.9% [95% CI: 31.2%; 32.6%] versus 2.2% [95% CI: 2.0%; 2.4%]).

CONCLUSIONS

The anticipated association between AI exposure and osteoporotic fracture risk in Japanese women with breast cancer was not seen clearly.

Long-term Follow-up and Safety of Patients after an Upfront Therapy with Letrozole for Early Breast Cancer in Routine Clinical Care - The PreFace Study

Introduction

Adjuvant treatment of patients with early-stage breast cancer (BC) should include an aromatase inhibitor (AI). Especially patients with a high recurrence risk might benefit from an upfront therapy with an AI for a minimum of five years. Nevertheless, not much is known about the patient selection for this population in clinical practice. Therefore, this study analyzed the prognosis and patient characteristics of postmenopausal patients selected for a five-year upfront letrozole therapy.

Patients and Methods

From 2009 to 2011, 3529 patients were enrolled into the adjuvant phase IV PreFace clinical trial (NCT01908556). Postmenopausal hormone receptor-positive BC patients, for whom an upfront five-year therapy with letrozole (2.5 mg/day) was indicated, were eligible. Disease-free survival (DFS), overall survival (OS) and safety in relation to patient and tumor characteristics were assessed.

Results

3297 patients started letrozole therapy. The majority of patients (n = 1639, 57%) completed the five-year treatment. 34.5% of patients continued with endocrine therapy after the mandated five-year endocrine treatment. Five-year DFS rates were 89% (95% CI: 88-90%) and five-year OS rates were 95% (95% CI: 94-96%). In subgroup analyses, DFS rates were 83%, 84% and 78% for patients with node-positive disease, G3 tumor grading, and pT3 tumors respectively. The main adverse events (any grade) were pain and hot flushes (66.8% and 18.3% of patients).

Conclusions

The risk profile of postmenopausal BC patients selected for a five-year upfront letrozole therapy showed a moderate recurrence and death risk. However, in subgroups with unfavorable risk factors, prognosis warrants an improvement, which might be achieved with novel targeted therapies.

Aromatase inhibitors: the journey from the state of the art to clinical open questions

Breast cancer is a major cause of death among females. Great advances have been made in treating this disease, and aromatase inhibitors (AIs) have been recognized as the cornerstone. They are characterized by high efficacy and low toxicity. The authors reviewed the available literature and defined state-of-the-art AI management. This study was designed to assist clinicians in addressing the need to equally weigh patients' needs and disease control rates in their everyday clinical practice. Today, AIs play a central role in the treatment of hormone receptor-positive breast cancer. In this study, an expert panel reviewed the literature on the use of AIs, discussing the evolution of their use in various aspects of breast cancer, from pre- and postmenopausal early breast cancer to metastatic breast cancer, along with their management regarding efficacy and toxicity. Given the brilliant results that have been achieved in improving survival in everyday clinical practice, clinicians need to address their concerns about therapy duration and the adverse effects they exert on bone health, the cardiovascular system, and metabolism. Currently, in addition to cancer treatment, patient engagement is crucial for improving adherence to therapy and supporting patients' quality of life, especially in a selected subset of patients, such as those receiving an extended adjuvant or combination with targeted therapies. A description of modern technologies that contribute to this important goal is provided.

Thromboembolism and Adjuvant Endocrine Therapy (AET) in Hormone Receptor-Positive Early Breast Cancer (EBC): Did Treatment Evolution Change Incidence of the Adverse Event? A Meta-Analysis

The adjuvant endocrine therapy (AET) of HR+ EBC has been changing in recent years. Aromatase inhibitors (AIs) as an upfront strategy (or as part of a switch strategy) have been added to the choice of Tamoxifen (T) alone. Increased TE risk is well known in T-treated patients, while AIs have shown a reduced TE rate. By adding the cyclin dependent kinase 4/6 inhibitors (CDK4/6) to AIs, an increase in TE rate has been shown. We conducted this meta-analysis to evaluate the impact of the AETs on TE incidence. Twelve randomized phase III trials were included. Four trials evaluated the upfront strategy, 6 assessed the switch and 2 the combination with a CDK4/6 inhibitor. The new AETs did not significantly modify or affect the rate of TE events (OR 0.847, 95% CI, 0.528-1.366, P = .489). The OR for CDK4/6 inhibitor plus ET vs. ET was 3.635 (P = .002). Excluding the CDK4/6 inhibitors, the overall OR for AIs vs. T was 0.628 (P < .001), while it was 0.781 (P = .151) for switching T vs. continuing T for 5 years, and 0.52 (P < .0001) for the upfront strategies with AIs. The AIs alone or plus CDK4/6 inhibitors did not affect the rate of TE events. AIs as an upfront strategy is the safest AET, associated with the lowest TE incidence. The switch strategy increases TE rate, whereas the addition of CDK4/6 to the standard AET was shown to significantly increase TE events. The results of the currently ongoing trials with CDK4/6 inhibitors will help obtain additional data to evaluate any differences among the different CDK4/6 inhibitors and clarify the weight of TE adverse events in the benefit/risk balance of this new adjuvant strategy.

Estrogen deprivation effects of endocrine therapy in breast cancer patients: Incidence, management and outcome

Endocrine therapy is one of the standard adjuvant treatments to reduce the risk of recurrence and mortality in patients with hormone receptor positive early breast cancer. Despite its proven efficacy, ET side effects, which persist over time even if low grade, may deteriorate quality of life. During follow-up visits, emphasis is generally placed on the risk of disease recurrence, while the topic of ET side effects is commonly neglected and discussed only briefly. This could lead to poor adherence to therapy and early treatment discontinuation, resulting in worse survival outcomes. The aim of this review is to provide an overview of the available evidence on the incidence and reporting of ET-related side effects (including vasomotor symptoms, musculoskeletal disorders and genitourinary syndrome of menopause, as well as fatigue, psychological and ocular disorders, dysmetabolic effects and loss of bone density) and of the pharmacological and non-pharmacological strategies available to mitigate symptom burden.

SEOM-GEICAM-SOLTI clinical guidelines for early-stage breast cancer (2022)

Breast cancer is the leading cause of cancer in women in Spain and its annual incidence is rapidly increasing. Thanks to the screening programs in place, nearly 90% of breast cancer cases are detected in early and potentially curable stages, despite the COVID-19 pandemic possibly having impacted these numbers (not yet quantified). In recent years, locoregional and systemic therapies are increasingly being directed by new diagnostic tools that have improved the balance between toxicity and clinical benefit. New therapeutic strategies, such as immunotherapy, targeted drugs, and antibody-drug conjugates have also improved outcomes in some patient subgroups. This clinical practice guideline is based on a systematic review of relevant studies and on the consensus of experts from GEICAM, SOLTI, and SEOM.

Impact of CDK4/6 Inhibitors on Aromatase Inhibitor-Associated Musculoskeletal Syndrome (AIMSS) in the Adjuvant Setting

Background

Third-generation aromatase inhibitors (AIs) are the mainstay of treatment in hormone receptor (HR)-positive breast cancer. Even though it is considered to be a well-tolerated therapy, AI-induced musculoskeletal symptoms are common and may be accused for treatment discontinuation. Recently, selective cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors changed the therapeutic setting, and currently, ribociclib, palbociclib, and abemaciclib are all approved in combination with nonsteroidal AIs in patients with ER-positive, HER2-negative advanced or metastatic breast cancer. This systematic review aims to identify the frequency of aromatase inhibitor-associated musculoskeletal syndrome (AIMSS) in the adjuvant setting in patients under AI monotherapy compared to patients under combination therapy with AIs and CDK4/6 inhibitors and demonstrate the underlying mechanism of action.

Methods

This study was performed in accordance with PRISMA guidelines. The literature search and data extraction from all randomized clinical trials (RCTs) were done by two independent investigators. Eligible articles were identified by a search of MEDLINE and ClinicalTrial.gov database concerning the period 2000/01/01-2021/05/01.

Results

Arthralgia was reported in 13.2 to 68.7% of patients receiving AIs for early-stage breast cancer, while arthralgia induced by CDK4/6 inhibitors occurred in a much lower rate [20.5-41.2%]. Bone pain (5-28.7% vs. 2.2-17.2%), back pain (2-13.4% vs. 8-11.2%), and arthritis (3.6-33.6% vs. 0.32%) were reported less frequently in patients receiving the combination of CDK4/6 inhibitors with ET.

Conclusions

CDK4/6 inhibitors might have a protective effect against joint inflammation and arthralgia occurrence. Further studies are warranted to investigate arthralgia incidence in this population.

Clinical and sociodemographic risk factors associated with the development of second primary cancers among postmenopausal breast cancer survivors

BACKGROUND

Advancement in breast cancer (BC) diagnosis and treatment have increased the number of long-term survivors. Consequently, primary BC survivors are at a greater risk of developing second primary cancers (SPCs). The risk factors for SPCs among BC survivors including sociodemographic characteristics, cancer treatment, comorbidities, and concurrent medications have not been comprehensively examined. The purpose of this study is to assess the incidence and clinicopathologic factors associated with risk of SPCs in BC survivors.

METHODS

We analyzed 171, 311 women with early-stage primary BC diagnosed between January 2000 and December 2015 from the Medicare-linked Surveillance Epidemiology and End Results (SEER-Medicare) database. SPC was defined as any diagnosis of malignancy occurring within the study period and at least 6 months after primary BC diagnosis. Univariate analyses compared baseline characteristics between those who developed a SPC and those who did not. We evaluated the cause-specific hazard of developing a SPC in the presence of death as a competing risk.

RESULTS

Of the study cohort, 21,510 (13%) of BC survivors developed a SPC and BC was the most common SPC type (28%). The median time to SPC was 44 months. Women who were white, older, and with fewer comorbidities were more likely to develop a SPC. While statins [hazard ratio (HR) 1.066 (1.023-1.110)] and anti-hypertensives [HR 1.569 (1.512-1.627)] increased the hazard of developing a SPC, aromatase inhibitor therapy [HR 0.620 (0.573-0.671)] and bisphosphonates [HR 0.905 (0.857-0.956)] were associated with a decreased hazard of developing any SPC, including non-breast SPCs.

CONCLUSION

Our study shows that specific clinical factors including type of cancer treatment, medications, and comorbidities are associated with increased risk of developing SPCs among older BC survivors. These results can increase patient and clinician awareness, target cancer screening among BC survivors, as well as developing risk-adapted management strategies.

Risk of Cardiovascular Events and Lipid Profile Change in Patients with Breast Cancer Taking Aromatase Inhibitor: A Systematic Review and Meta-Analysis

Cardiovascular disease (CVD) is one of the most common comorbidities in breast cancer survivors. Recently, the target population and treatment period for aromatase inhibitor (AI) treatment in breast cancer patients has been expanding. However, information on adverse CVD events from the long-term use of AI is still lacking. The aim of this study was to investigate the CVD side effects of AI treatment and to evaluate the changes in lipid profile during AI treatment. A systematic search of PubMed (Medline), EMBASE, and Cochrane Library databases reporting on cardiovascular outcomes or lipid profiles change in adult female breast cancer patients (>19 years old) with AI was performed. The pooled analysis of 25 studies showed that the prevalence rate of any type of cardiovascular disease was 6.08 per 100 persons (95% CI 2.91-10.31). Angina was the most common type of heart-related cardiovascular event accounting for 3.85 per 100 persons, followed by any type of stroke (3.34) and venous thromboembolism (2.95). Ischemic stroke (OR 1.39, 95% CI 1.07-1.81) and myocardial infarction (OR 1.30, 95% CI 0.88-1.93) were more common in AI compared with tamoxifen, whereas the prevalence of venous thromboembolism (OR 0.61, 95% CI 0.37-1) was significantly lower in the AI group. In addition, treatment with AI for 6-12 months showed a decrease in HDL-cholesterol and an increase in LDL-cholesterol and total cholesterol. Various CVDs can occur when using AI, and in particular, the risk of MI and ischemic stroke increases in comparison with the adverse effect of tamoxifen. The occurrence of CVD might be related to the deterioration of the lipid profile after AI treatment. Therefore, a customized individualization strategy considering each patient's CV risk factors is needed during AI treatment.

Prevention of aromatase inhibitor-induced bone loss with anti-resorptive therapy in post-menopausal women with early-stage breast cancer

We assessed if antiresorptive treatment can prevent aromatase inhibitor-induced bone loss in patients with early breast cancer. We observed that patients who did not receive antiresorptive treatment had a 20.8-fold increase in risk of bone loss after 24 months of aromatase inhibitors therapy.

PURPOSE

This study aimed to describe changes in femoral and lumbar bone mineral density (BMD) after 24 months of aromatase inhibitors (AIs) and antiresorptive treatment in postmenopausal women with estrogen receptor-positive breast cancer.

METHODS

Prospective, longitudinal study in a real-life setting with a 2-year follow-up. Patients underwent a complete baseline bone assessment including clinical assessment, biological evaluation, BMD measurement, and spine X-ray. Antiresorptive treatment was prescribed to patients with a T-score <  - 2 or a T-score <  - 1.5 SD with additional osteoporosis risk factors. A follow-up bone assessment was carried out after 24 months.

RESULTS

Among 328 patients referred to our center, 168 patients (67.7 ± 10.6 years) were included in our study, and 144 were eligible for antiresorptive treatment. After 24 months, patients receiving antiresorptive treatment experienced a significant increase of + 6.28% in femoral-BMD (F-BMD) and + 7.79% in lumbar-BMD (L-BMD). This increase was not significantly different between osteoporotic and osteopenic patients. Conversely, patients not receiving antiresorptive treatment presented significant F-BMD and L-BMD loss regardless of the baseline BMD. In the multivariate logistic model, the lack of antiresorptive treatment was the only predictive factor for major femoral bone loss with a 20.83 odds ratio (CI95%:4.2-100, p < 0.001).

CONCLUSION

This real-life study confirmed that antiresorptive treatment significantly increases femoral and lumbar BMD regardless of the baseline BMD in postmenopausal patients receiving AIs for early breast cancer. Patients who did not receive antiresorptive treatment had a 20.8-fold increased risk of major bone loss. Nevertheless, the best threshold to adopt for starting antiresorptive agents remains undetermined.

Extended Adjuvant Endocrine Treatment in Luminal Breast Cancers in the Era of Genomic Tests

In patients with early-stage endocrine receptor-positive (ER+) breast cancer (BC), adjuvant endocrine therapy (ET) for 5 years is the standard of care. However, for some patients, the risk of recurrence remain high for up to 15 years after diagnosis and extended ET beyond 5 years may be a reasonable option. Nevertheless, this strategy significantly increases the occurrence of side effects. Here we summarize the available evidence from randomized clinical trials on the efficacy and safety profile of extended ET and discuss available clinical and genomic tools helpful to select eligible patients in daily clinical practice.

Endocrine therapy initiation among women with stage I-III invasive, hormone receptor-positive breast cancer from 2001-2016

PURPOSE

This retrospective cohort study examined patterns of endocrine therapy initiation over time and by demographic, tumor, and treatment characteristics.

METHODS

We included 7777 women from three U.S. integrated healthcare systems diagnosed with incident stage I-III hormone receptor-positive breast cancer between 2001 and 2016. We extracted endocrine therapy from pharmacy dispensings, defining initiation as dispensings within 12 months of diagnosis. Demographic, tumor, and treatment characteristics were collected from electronic health records. Using generalized linear models with a log link and Poisson distribution, we estimated initiation of any endocrine therapy, tamoxifen, and aromatase inhibitors (AI) over time with relative risks (RR) and 95% confidence intervals (CI) adjusted for age, tumor characteristics, diagnosis year, other treatment, and study site.

RESULTS

Among women aged 20+ (mean 62 years), 6329 (81.4%) initiated any endocrine therapy, and 1448 (18.6%) did not initiate endocrine therapy. Tamoxifen initiation declined from 67 to 15% between 2001 and 2016. AI initiation increased from 6 to 69% between 2001 and 2016 in women aged ≥ 55 years. The proportion of women who did not initiate endocrine therapy decreased from 19 to 12% between 2002 and 2014 then increased to 17% by 2016. After adjustment, women least likely to initiate endocrine therapy were older (RR = 0.81, 95% CI 0.77-0.85 for age 75+ vs. 55-64), Black (RR = 0.93, 95% CI 0.87-1.00 vs. white), and had stage I disease (RR = 0.88, 95% CI 0.85-0.91 vs. stage III).

CONCLUSIONS

Despite an increase in AI use over time, at least one in six eligible women did not initiate endocrine therapy, highlighting opportunities for improving endocrine therapy uptake in breast cancer survivors.

Lipid Changes During Endocrine Therapy in Breast Cancer Patients: The Results of a 5-Year Real-World Retrospective Analysis

Background

The aim of this study was to investigate the status of serum lipids during endocrine therapy.

Methods

We retrospectively analysed lipid profiles during the 5-year treatment of 1487 consecutive postoperative BC patients. Lipid parameters included triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C). Those biomarkers were measured at baseline and 1, 2, 3, 4 and 5 years following the initiation of endocrine therapy.

Results

For premenopausal BC patients, LDL levels rapidly decreased at 1 year in the tamoxifen (TAM) group compared with baseline levels (p<0.05), and this decline remained for the following 4 years. Additionally, LDL levels were significantly lower in the TAM group than in the nonendocrine group at all assessment time points (p<0.05). Similarly, TC levels also decreased in the TAM group compared with baseline levels at all assessment time points (p<0.05), and compared with the levels in the nonendocrine group, TC levels were also lower for the first 4 years. For postmenopausal BC patients, there was no significant difference in the lipid profiles (TG, TC, LDL and HDL) in the letrozole (LET), anastrozole (ANA) or exemestane (EXE) groups compared with the nonendocrine group. For patients who received TAM, compared with the nonendocrine group, TC levels decreased at 1 year, and LDL levels decreased at 1 and 2 years.

Conclusions

TAM may improve LDL and TC levels in premenopausal BC patients. In postmenopausal BC patients, aromatase inhibitors (AIs) may have no adverse effects on lipid profiles, and TAM may have limited beneficial effects on serum lipids.

Extended therapy with letrozole as adjuvant treatment of postmenopausal patients with early-stage breast cancer: a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

The benefit of extending aromatase inhibitor therapy beyond 5 years in the context of previous aromatase inhibitors remains controversial. We aimed to compare extended therapy with letrozole for 5 years versus the standard duration of 2-3 years of letrozole in postmenopausal patients with breast cancer who have already received 2-3 years of tamoxifen.

METHODS

This multicentre, open-label, randomised, phase 3 trial was done at 69 hospitals in Italy. Women were eligible if they were postmenopausal at the time of study entry, had stage I-III histologically proven and operable invasive hormone receptor-positive breast cancer, had received adjuvant tamoxifen therapy for at least 2 years but no longer than 3 years and 3 months, had no signs of disease recurrence, and had an Eastern Cooperative Oncology Group performance status of 2 or lower. Patients were randomly assigned (1:1) to receive 2-3 years (control group) or 5 years (extended group) of letrozole (2·5 mg orally once a day). Randomisation, with stratification by centre, with permuted blocks of size 12, was done with a centralised, interactive, internet-based system that randomly generated the treatment allocation. Participants and investigators were not masked to treatment assignment. The primary endpoint was invasive disease-free survival in the intention-to-treat population. Safety analysis was done for patients who received at least 1 month of study treatment. This trial was registered with EudraCT, 2005-001212-44, and ClinicalTrials.gov, NCT01064635.

FINDINGS

Between Aug 1, 2005, and Oct 24, 2010, 2056 patients were enrolled and randomly assigned to receive letrozole for 2-3 years (n=1030; control group) or for 5 years (n=1026; extended group). After a median follow-up of 11·7 years (IQR 9·5-13·1), disease-free survival events occurred in 262 (25·4%) of 1030 patients in the control group and 212 (20·7%) of 1026 in the extended group. 12-year disease-free survival was 62% (95% CI 57-66) in the control group and 67% (62-71) in the extended group (hazard ratio 0·78, 95% CI 0·65-0·93; p=0·0064). The most common grade 3 and 4 adverse events were arthralgia (22 [2·2%] of 983 patients in the control group vs 29 [3·0%] of 977 in the extended group) and myalgia (seven [0·7%] vs nine [0·9%]). There were three (0·3%) serious treatment-related adverse events in the control group and eight (0·8%) in the extended group. No deaths related to toxic effects were observed.

INTERPRETATION

In postmenopausal patients with breast cancer who received 2-3 years of tamoxifen, extended treatment with 5 years of letrozole resulted in a significant improvement in disease-free survival compared with the standard 2-3 years of letrozole. Sequential endocrine therapy with tamoxifen for 2-3 years followed by letrozole for 5 years should be considered as one of the optimal standard endocrine treatments for postmenopausal patients with hormone receptor-positive breast cancer.

FUNDING

Novartis and the Italian Ministry of Health.

TRANSLATION

For the Italian translation of the abstract see Supplementary Materials section.

Effect of Traditional Chinese Medicine on Musculoskeletal Symptoms in Breast Cancer: A Systematic Review and Meta-Analysis

CONTEXT

Traditional Chinese Medicine (TCM) has been widely used as a complementary medical treatment for arthralgia and other types of pain. The available literature on the effectiveness of TCM on breast cancer patients with musculoskeletal symptoms reports controversial results.

OBJECTIVES

The objective of this review is to assess the effectiveness of TCM as a treatment option for musculoskeletal symptoms in patients with breast cancer who were treated with aromatase inhibitors (AIs).

METHODS

A comprehensive literature search was conducted using PubMed, the Cochrane Library, SAGE journals, Scopus, EMBASE, Web of Science, Medline, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), Wanfang, and Chinese Medical Journal Database (CMJ) from May 2020 to November 2020. The literature review included randomized controlled trials (RCTs) of TCM for AI-related musculoskeletal symptoms.

RESULTS

Four RCTs incorporating TCM were assessed by meta-analysis and reported favorable effects in reducing worst pain score (n = 284, mean difference [MD]: 2.31; 95% CI, 1.74 to 2.88; P < 0.00001). Three trials showed favorable effects of TCM in reducing pain interference (n = 211, MD: 2.62; 95% CI, 1.29 to 3.94; P = 0.0001), while two trials reported no significant effects of TCM on stiffness (n = 147, MD: 1.21; 95% CI, -0.39 to 2.82; P = 0.14). The meta-analysis of three trials also found no significant effect of TCM on bone mineral density (n = 214, MD, -0.01; 95% CI, -0.07 to 0.05; P = 0.71). The physical aspect of quality of life was significantly increased in breast cancer patients after TCM treatment (n = 220, MD, 5.13; 95% CI, 2.04 to 8.22; P = 0.001). In addition, three RCTs reported minimal TCM-related adverse events.

CONCLUSION

The results suggest that TCM could be an effective treatment in relieving pain especially worst pain and pain interference as well as improving quality of life caused by AI-related musculoskeletal symptoms. However, further investigation of the molecular pathway involved and in-depth safety profile are needed.

Practical consensus recommendations on duration of adjuvant hormonal therapy in breast cancer

Optimization of adjuvant systemic therapy in women with early-stage hormone receptor-positive breast cancer includes the consideration of chemotherapy and duration of hormone therapy. Adjuvant hormonal therapy significantly improves long-term survival of breast cancer patients with hormone receptor-positive disease. Despite the proven clinical efficacy of tamoxifen and aromatase inhibitors, many breast cancer survivors either fail to take the correct dosage at the prescribed frequency (adherence) or discontinue therapy (persistence). Expert oncologist discussed on the duration of adjuvant hormonal therapy for improvement of OS and quality of life of breast cancer patients by providing reduction in recurrence and mortality. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at this practical consensus recommendations for the benefit of community oncologists.

Osteoporotic Fractures of the Spine, Hip, and Other Locations after Adjuvant Endocrine Therapy with Aromatase Inhibitors in Breast Cancer Patients: a Meta-analysis

BACKGROUND

Aromatase inhibitors (AIs) play an important role in the endocrine therapy of postmenopausal breast cancer patients, with a recent tendency to extend the duration of their use. However, AIs may increase the risk of osteoporotic bone fractures. This meta-analysis evaluated the risk of osteoporotic fractures of the hip, spine, and other locations in breast cancer patients using AIs.

METHODS

We performed a systematic search to identify randomized controlled clinical trials that investigated osteoporotic fractures in breast cancer patients on AI therapy. The main outcomes were the incidence and risk of osteoporotic fractures in general and of hip, vertebral, and non-vertebral fractures in AI users and controls.

RESULTS

The systematic review found a total of 30 randomized controlled trials including 117,974 participants. The meta-analysis showed a higher incidence of osteoporotic fracture in AI users: The crude risk ratio for all osteoporotic fractures was 1.35 (95% confidence interval [CI], 1.29-1.42; P < 0.001), for hip fractures 1.18 (95% CI, 1.02-1.35; P < 0.001), for vertebral fractures 1.84 (95% CI, 1.36-2.49; P < 0.001), and for non-vertebral fractures 1.18 (95% CI, 1.02-1.35; P < 0.001), respectively, compared to the controls.

CONCLUSION

Our meta-analysis suggested an increased risk of osteoporotic fractures for AI therapy in patients with breast cancer that was most expressed for vertebral fractures. Breast cancer patients on AIs need to be monitored for osteoporosis and osteoporotic fractures, and active prevention measures should be implemented.

Cumulative incidence of cardiovascular events under tamoxifen and letrozole alone and in sequence: a report from the BIG 1-98 trial

BACKGROUND

Compared to tamoxifen, adjuvant treatment with aromatase inhibitors improves disease outcomes of postmenopausal women with hormone receptor-positive early breast cancer. In the international, randomized, double-blind BIG 1-98 trial, 8010 women were randomized to receive tamoxifen, letrozole, or sequential use of the agents for 5 years. With a focus on switching between agents, we investigated cardiovascular events over the entire 5-year treatment period.

METHODS

Of the 6182 patients enrolled, 6144 started trial treatment and were included in this analysis. Adverse events occurring during study treatment until 30 days after cessation were considered. Eight cardiovascular event types were defined. Cumulative incidence of events were estimated using the Kaplan-Meier method, without consideration for competing events. Multivariable Cox models estimated hazard ratios (HR) with 95% confidence intervals (CI) for pairwise comparisons of treatment arms.

RESULTS

While on study treatment, 6.5% of patients (n = 397) had any cardiac events reported; for 2.4%, the event was grades 3-5, of which 11 (0.2%) were grade 5. Letrozole monotherapy was associated with higher risk of grade 1-5 ischemic heart disease (HR = 1.81; 95% CI, 1.06-3.08) compared with tamoxifen monotherapy. Patients assigned sequential tamoxifen →letrozole (HR = 1.59; 95% CI, 0.92-2.74) or sequential letrozole → tamoxifen (HR = 1.20; 95% CI, 0.68-2.14) showed a lesser degree of risk elevation. Patients assigned to tamoxifen-containing regimens had significantly higher risk of grade 1-5 thromboembolic events (tamoxifen monotherapy HR = 2.10; 95% CI, 1.42-3.12; tamoxifen → letrozole HR = 1.96; 95% CI, 1.32-2.92; letrozole → tamoxifen HR = 1.56; 95% CI 1.03-2.35) as compared with patients assigned letrozole alone.

CONCLUSION

When initiating or switching between adjuvant endocrine treatments in postmenopausal patients, age and medical history, with special attention to prior cardiovascular events, should be balanced with expected benefit of the treatment.

Application of the ESMO-Magnitude of Clinical Benefit Scale (V.1.1) to the field of early breast cancer therapies

Click here to listen to the Podcast BACKGROUND: The European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated value scale for solid tumour anticancer treatments. Form 1 of the ESMO-MCBS, used to grade therapies with curative intent including adjuvant therapies, has only been evaluated for a limited number of studies. This is the first large-scale field testing in early breast cancer to assess the applicability of the scale to this data set and the reasonableness of derived scores and to identify any shortcomings to be addressed in future modifications of the scale.

METHOD

Representative key studies and meta-analyses of the major modalities of adjuvant systemic therapy of breast cancer were identified for each of the major clinical scenarios (HER2-positive, HER2-negative, endocrine-responsive) and were graded with form 1 of the ESMO-MCBS. These generated scores were reviewed by a panel of experts for reasonableness. Shortcomings and issues related to the application of the scale and interpretation of results were identified and critically evaluated.

RESULTS

Sixty-five studies were eligible for evaluation: 59 individual studies and 6 meta-analyses. These studies incorporated 101 therapeutic comparisons, 61 of which were scorable. Review of the generated scores indicated that, with few exceptions, they generally reflected contemporary standards of practice. Six shortcomings were identified related to grading based on disease-free survival (DFS), lack of information regarding acute and long-term toxicity and an inability to grade single-arm de-escalation scales.

CONCLUSIONS

Form 1 of the ESMO-MCBS is a robust tool for the evaluation of the magnitude of benefit studies in early breast cancer. The scale can be further improved by addressing issues related to grading based on DFS, annotating grades with information regarding acute and long-term toxicity and developing an approach to grade single-arm de-escalation studies.

Molecular mechanisms and clinical management of cancer bone metastasis

As one of the most common metastatic sites of malignancies, bone has a unique microenvironment that allows metastatic tumor cells to grow and flourish. The fenestrated capillaries in the bone, bone matrix, and bone cells, including osteoblasts and osteoclasts, together maintain the homeostasis of the bone microenvironment. In contrast, tumor-derived factors act on bone components, leading to subsequent bone resorption or excessive bone formation. The various pathways involved also provide multiple targets for therapeutic strategies against bone metastases. In this review, we summarize the current understanding of the mechanism of bone metastases. Based on the general process of bone metastases, we specifically highlight the complex crosstalk between tumor cells and the bone microenvironment and the current management of cancer bone metastases.

Evolution in the risk of adverse events of adjuvant endocrine therapy in postmenopausal women with early-stage breast cancer

BACKGROUND

Adjuvant endocrine therapy is a gold standard in early-stage, hormone receptor positive breast cancer. In postmenopausal women, aromatase inhibitors (AIs) are associated with improved outcome compared to tamoxifen monotherapy. Differences in the toxicity profiles of these drugs are described; however, little is known about whether the risk of adverse events changes over time.

METHODS

Sequential reports of large, randomized, adjuvant endocrine therapy trials comparing AIs to tamoxifen were reviewed. Data on pre-specified adverse events were extracted including cardiovascular events, bone fractures, cerebrovascular disease, endometrial cancer, secondary malignancies excluding breast cancer, venous thrombosis and death without recurrence. Odds ratios (ORs) were calculated for each adverse event at each time over the course of follow-up. The change in the ORs for adverse events over time was evaluated using weighted linear regression.

RESULTS

Analysis included 21 reports of 7 trials comprising 30,039 patients and reporting outcomes between 28 and 128 months of follow-up. Compared to tamoxifen, AIs use was associated with a significant reduction in the magnitude of increased odds of bone fracture over time (β = - 0.63, p = 0.013). There was a non-significant decrease in the magnitude of reduced odds of secondary malignancies over time (β = 0.448, p = 0.094). The differences in other toxicity profiles between AIs and tamoxifen did not change significantly over time.

CONCLUSIONS

The increased risk of bone fractures associated with adjuvant AIs falls over time and after discontinuation of treatment. Differences in other toxicities between AIs and tamoxifen do not change significantly over time including a persistently elevated risk of cardiovascular events.

Endocrine therapy with or without whole breast irradiation in low-risk breast cancer patients after breast-conserving surgery: 10-year results of the Austrian Breast and Colorectal Cancer Study Group 8A trial

PURPOSE

To investigate long-term results of patients with hormonal receptor-positive breast cancer treated with breast-conserving surgery (BCS) and consecutive endocrine therapy (ET) with or without whole breast irradiation (WBI).

METHODS AND MATERIALS

Within the 8 A trial of the Austrian Breast and Colorectal Cancer Study Group, a total of 869 patients received ET after BCS which was randomly followed by WBI (n = 439, group 1) or observation (n = 430, group 2). WBI was applied up to a mean total dosage of 50 Gy (+/- 10 Gy boost) in conventional fractionation.

RESULTS

After a median follow-up of 9.89 years, 10 in-breast recurrences (IBRs) were observed in group 1 and 31 in group 2, resulting in a 10-year local recurrence-free survival (LRFS) of 97.5% and 92.4%, respectively (p = 0.004). This translated into significantly higher rates for disease-free survival (DFS): 94.5% group 1 vs 88.4% group 2, p = 0.0156. For distant metastases-free survival (DMFS) and overall survival (OS), respective 10-year rates amounted 96.7% and 86.6% for group 1 versus 96.4% and 87.6%, for group 2 (ns). WBI (hazard ratio [HR]: 0.27, p < 0.01) and tumour grading (HR: 3.76, p = 0.03) were found as significant predictors for IBR in multiple cox regression analysis.

CONCLUSIONS

After a median follow-up of 10 years, WBI resulted in a better local control and DFS compared with ET alone. The omission of WBI and tumour grading, respectively, were the only negative predictors for LRFS.

Tamoxifen-induced hepatotoxicity via lipid accumulation and inflammation in zebrafish

Tamoxifen is a clinical drug for estrogen receptor (ER)-positive breast cancer. Recently, it has been detected in aquatic environment. The residual drugs will produce certain biological activity and create a risk to aquatic organism when they enter the water environment. Therefore, it has great significance to study the ecotoxicity of tamoxifen. In the study, we used zebrafish as a model of aquatic to investigate the ecotoxic mechanism of tamoxifen to aquatic. We found that tamoxifen induced liver lipid accumulation in zebrafish, which showed a significant hepatotoxicity with smaller liver area and bigger yolk area. Though biochemical and pathologic measurement, tamoxifen treated group showed higher transaminase and lipid content. The elevated liver lipid synthesis might due to the increase of lipid metabolism related gene Srebf1, Srebf2 and Fasn. Moreover, inflammatory cytokine Tnf-α, Il-1β And Il-6 were increased. This result confirmed the toxicity of tamoxifen to aquatic, suggested liver injury was the main characteristic of its ecotoxicity. This study indicated it is important to avoid tamoxifen discharging into the aquatic ecology and provided a theoretical basis of prevention tamoxifen-induced ecotoxicity to aquatic.

Aromatase inhibitors and risk of cardiovascular events in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Cardiovascular events (CVEs) was considered as one of the primary cause to reduce the quality of life in breast cancer patients with aromatase inhibitors (AIs) treatment, which has not been sufficiently addressed. The aim of this study was to assess the correlation between risk of CVEs and AIs in patients with breast cancer.

METHODS

Included studies were obtained from the databases of Embase, Pubmed, Cochrane Library, Clinical Trials.gov, and reference lists. The main outcome measures were overall incidence, odds ratios (ORs), and 95% confidence intervals (CIs). Furthermore, the association and the risk differences among different tumor types, AIs,ages,or treatment regimens were conducted. Fixed-effect or random-effect models were applied in the statistical analyses according to the heterogeneity. Our analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

Seventeen studies, which included 44,411 subjects, were included in our analyses. The overall incidence of CVEs in AIs group was 13.02% (95% CI: 8.15-20.17%) and almost all of the high-grade CVEs occurred in patients treated with AIs. The pooled ORs of CVEs was 0.9940 (95% CI: 0.8545-1.1562). Under sub-group analysis, the incidence of CVEs related to exemestane was higher than that of controls (OR = 1.1564, 95% CI: 1.0656-1.2549), but no statistical differences in risk of CVEs were found in other sub-group analysis. No evidence of publication bias was found for incidence of CVEs in our meta-analysis by a funnel plot.

CONCLUSIONS

These results suggest that patients with breast cancer treated with AIs do not have a significant risk of developing CVEs in comparison with the controls, and exemestane might not be considered as the alternative AI to the breast cancer patients from the perspective of CVEs. Further studies are recommended to investigate this association and the risk differences among different tumor types, AIs or treatment regimens.

French recommendations on strategies for preventing and treating osteoporosis induced by adjuvant breast cancer therapies

Standard adjuvant therapies for breast cancer such as chemotherapy or aromatase inhibitor and LH-RH agonist hormone therapy are associated with significant survival gains but also induce bone loss by aggravating the estrogen deprivation. The bone loss may be substantial, notably during early treatment, and occurs regardless of the baseline bone mineral density values. The objective of developing these recommendations was to achieve a practical consensus among various scientific societies, based on literature review, about osteoporosis prevention and treatment in these patients. The following scientific societies contributed to the work: Société Française de Rhumatologie (SFR), Groupe de Recherche et d'Information sur les Ostéoporoses (GRIO), Groupe Européen d'Etudes des Métastases Osseuses (GEMO), Association Francophone pour les Soins Oncologiques de Support (AFSOS), Société Française de Sénologie et de Pathologie Mammaire (SFSPM), Société Française de Radiothérapie Oncologique (SFRO). Drug prescription and reimbursement modalities in France were taken into account. These recommendations apply to postmenopausal women taking systemic chemotherapy and/or aromatase inhibitor therapy, non-postmenopausal women taking LH-RH agonist therapy, and non-postmenopausal women with persistent amenorrhea 1 year after chemotherapy completion. All women in these three categories should undergo an evaluation of bone health and receive interventions to combat risk factors for bone loss. Patients with a history of severe osteoporotic fracture and/or a T-score value <-2.5 should receive osteoporosis drug therapy. The FRAX® score should be used to guide treatment decisions in patients whose T-score is between -1 and -2.5. General osteoporosis prevention measures should be applied in patients without criteria for osteoporosis drug therapy, who should undergo bone mineral density measurements 18-24 months later if the baseline T-score is<-1 and 3-5 years later if the baseline T-score is>-1. The anti-tumor effect of bisphosphonates and denosumab was not considered when establishing these recommendations.

SEOM clinical guidelines in early stage breast cancer (2018)

Breast cancer is the most common cancer in women in our country and it is usually diagnosed in the early and potentially curable stages. Nevertheless, around 20-30% of patients will relapse despite appropriate locoregional and systemic therapies. A better knowledge of this disease is improving our ability to select the most appropriate therapy for each patient with a recent diagnosis of an early stage breast cancer, minimizing unnecessary toxicities and improving long-term efficacy.

Incidence of menopausal symptoms in postmenopausal breast cancer patients treated with aromatase inhibitors

Aromatase inhibitors (AIs) are the standard of care for postmenopausal women with estrogen receptor-positive breast cancer. Here, we performed a meta-analysis to evaluate the occurrence of menopausal symptoms in breast cancer patients receiving the AI therapy. Patients treated with AIs had an increased risk of all-grade arthralgia (1.63 [95% CI: 1.34–1.98]) and insomnia (1.24 [95% CI: 1.14–1.34]). The overall incidence of hot flashes, fatigue, arthralgia, sweating, and insomnia in patients receiving AIs was 30.47% (95% CI: 25.51%–35.93%), 17.16% (95% CI: 14%–20.85%), 17.91% (95% CI: 11.29%–27.22%), 14.64% (95% CI: 11.46%–18.52%), and 16.52% (95% CI: 12.45%–21.6 %), respectively. Both arthralgia (RR = 0.34, 95% CI: 0.16–0.75) and sweating (RR = 11.02, 95% CI: 4.11–29.57) differed between patients with early- and advanced-stage breast cancer. Our findings indicates that AIs are associated with a significant risk of developing arthralgia and insomnia in breast cancer patients. Effective early detection and management of menopausal symptoms would likely lead to safer use of AIs in breast cancer patients.

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.

Adjuvant anastrozole versus exemestane versus letrozole, upfront or after 2 years of tamoxifen, in endocrine-sensitive breast cancer (FATA-GIM3): a randomised, phase 3 trial

BACKGROUND

Uncertainty exists about the optimal schedule of adjuvant treatment of breast cancer with aromatase inhibitors and, to our knowledge, no trial has directly compared the three aromatase inhibitors anastrozole, exemestane, and letrozole. We investigated the schedule and type of aromatase inhibitors to be used as adjuvant treatment for hormone receptor-positive early breast cancer.

METHODS

FATA-GIM3 is a multicentre, open-label, randomised, phase 3 trial of six different treatments in postmenopausal women with hormone receptor-positive early breast cancer. Eligible patients had histologically confirmed invasive hormone receptor-positive breast cancer that had been completely removed by surgery, any pathological tumour size, and axillary nodal status. Key exclusion criteria were hormone replacement therapy, recurrent or metastatic disease, previous treatment with tamoxifen, and another malignancy in the previous 10 years. Patients were randomly assigned in an equal ratio to one of six treatment groups: oral anastrozole (1 mg per day), exemestane (25 mg per day), or letrozole (2·5 mg per day) tablets upfront for 5 years (upfront strategy) or oral tamoxifen (20 mg per day) for 2 years followed by oral administration of one of the three aromatase inhibitors for 3 years (switch strategy). Randomisation was done by a computerised minimisation procedure stratified for oestrogen receptor, progesterone receptor, and HER2 status; previous chemotherapy; and pathological nodal status. Neither the patients nor the physicians were masked to treatment allocation. The primary endpoint was disease-free survival. The minimum cutoff to declare superiority of the upfront strategy over the switch strategy was assumed to be a 2% difference in disease-free survival at 5 years. Primary efficacy analyses were done by intention to treat; safety analyses included all patients for whom at least one safety case report form had been completed. Follow-up is ongoing. This trial is registered with the European Clinical Trials Database, number 2006-004018-42, and ClinicalTrials.gov, number NCT00541086.

FINDINGS

Between March 9, 2007, and July 31, 2012, 3697 patients were enrolled into the study. After a median follow-up of 60 months (IQR 46-72), 401 disease-free survival events were reported, including 211 (11%) of 1850 patients allocated to the switch strategy and 190 (10%) of 1847 patients allocated to upfront treatment. 5-year disease-free survival was 88·5% (95% CI 86·7-90·0) with the switch strategy and 89·8% (88·2-91·2) with upfront treatment (hazard ratio 0·89, 95% CI 0·73-1·08; p=0·23). 5-year disease-free survival was 90·0% (95% CI 87·9-91·7) with anastrozole (124 events), 88·0% (85·8-89·9) with exemestane (148 events), and 89·4% (87·3 to 91·1) with letrozole (129 events; p=0·24). No unexpected serious adverse reactions or treatment-related deaths occurred. Musculoskeletal side-effects were the most frequent grade 3-4 events, reported in 130 (7%) of 1761 patients who received the switch strategy and 128 (7%) of 1766 patients who received upfront treatment. Grade 1 musculoskeletal events were more frequent with the upfront schedule than with the switch schedule (924 [52%] of 1766 patients vs 745 [42%] of 1761 patients). All other grade 3-4 adverse events occurred in less than 2% of patients in either group.

INTERPRETATION

5 years of treatment with aromatase inhibitors was not superior to 2 years of tamoxifen followed by 3 years of aromatase inhibitors. None of the three aromatase inhibitors was superior to the others in terms of efficacy. Therefore, patient preference, tolerability, and financial constraints should be considered when deciding the optimal treatment approach in this setting.

FUNDING

Italian Drug Agency.

Ageing perceptions and non-adherence to aromatase inhibitors among breast cancer survivors

PURPOSE

Aromatase inhibitors (AIs) are a potentially life-saving treatment for breast cancer survivors, yet poor adherence to treatment is a prevalent problem. A common adverse effect of AI treatment is arthralgia, which is identified by survivors as a major reason for treatment discontinuation. Women who experience arthralgia on AIs often report feeling they have aged rapidly while on the treatment. In the present study, we examined whether arthralgia-associated ageing perceptions predicted non-adherence.

PATIENTS AND METHODS

We conducted a prospective cohort study among women with stage I-III breast cancer, who were on an AI and completed the Penn Arthralgia Aging Scale within 2 years of AI initiation. Adherence data were abstracted from medical charts by trained raters. Cox proportional hazard analysis was used to determine the relationship between ageing perceptions and time to non-adherence. All analyses included adjustments for joint pain severity.

RESULTS

Among 509 participants, 144 (28.3%) were non-adherent. As hypothesised, women with high levels of ageing perceptions were at greater risk of non-adherence than women with low levels of ageing perceptions (adjusted hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.10-2.67; p = .02). High levels of depressive symptoms were also uniquely associated with increased risk of non-adherence (adjusted HR, 1.63; 95% CI, 1.03-2.59; p = .04).

CONCLUSION

Perceptions of ageing related to arthralgia and depressive symptoms predicted non-adherence to AIs. These findings suggest that interventions that address negative beliefs about ageing due to AI-related arthralgia and depressive mood can potentially improve rates of adherence to AIs.

Cardiotoxicity of aromatase inhibitors and tamoxifen in postmenopausal women with breast cancer: a systematic review and meta-analysis of randomized controlled trials

Background

Aromatase inhibitors (AIs) have been associated with cardiovascular disease in adjuvant randomized controlled trials (RCTs) comparing these drugs to tamoxifen. However, it is unclear whether this risk is real or due to cardioprotective effects of tamoxifen. To address this question, we conducted a systematic review and meta-analysis of all RCTs of AIs and tamoxifen in adjuvant and extended adjuvant setting.

Patients and methods

We searched PubMed, Embase (OVID), Cochrane CENTRAL, WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov from inception to June 2016 for all RCTs comparing cardiovascular and cerebrovascular safety of AIs to tamoxifen, AIs to placebo or no-treatment, or tamoxifen to placebo or no-treatment in the adjuvant or extended adjuvant setting. Relative risks (RRs) were pooled using DerSimonian and Laird random-effects models with analyses stratified by RCT design.

Results

A total of 19 RCTs were included in the meta-analysis (n  =  62 345). In the adjuvant setting, AIs were associated with a 19% (RR: 1.19, 95% confidence interval [CI]: 1.07-1.34) increased risk of cardiovascular events compared with tamoxifen. AIs were not associated with an increased risk compared with placebo in the extended-adjuvant setting (RR: 1.01, 95% CI: 0.85-1.20). In the adjuvant setting, tamoxifen was associated with a 33% (RR: 0.67, 95% CI: 0.45-0.98) decreased risk compared with placebo or no-treatment. The results from extended adjuvant RCTs comparing tamoxifen to placebo were inconclusive but suggestive of a small protective effect (RR: 0.91, 95% CI: 0.77-1.07).

Conclusions

The increased risk of cardiovascular events with AIs relative to tamoxifen is likely the result of cardioprotective effects of the latter. This new evidence should be considered when assessing the benefits and risks of AIs in the treatment of breast cancer.

Low-trauma fractures without osteoporosis

In clinical practice, areal bone mineral density (aBMD) is usually measured using dual-energy X-ray absorptiometry (DXA) to assess bone status in patients with or without osteoporotic fracture. As BMD has a Gaussian distribution, it is difficult to define a cutoff for osteoporosis diagnosis. Based on epidemiological considerations, WHO defined a DXA-based osteoporosis diagnosis with a T-score <-2.5. However, the majority of individuals who have low-trauma fractures do not have osteoporosis with DXA (i.e., T-score <-2.5), and some of them have no decreased BMD at all. Some medical conditions (spondyloarthropathies, chronic kidney disease and mineral bone disorder, diabetes, obesity) or drugs (glucocorticoids, aromatase inhibitors) are more prone to cause fractures with subnormal BMD. In the situation of fragility fractures with subnormal or normal BMD, clinicians face a difficulty as almost all the pharmacologic treatments have proved their efficacy in patients with low BMD. However, some data are available in post hoc analyses in patients with T score >-2. Overall, in patients with a previous fragility fracture (especially vertebra or hip), treatments appear to be effective. Thus, the authors recommend treating some patients with a major fragility fracture even if areal BMD T score is above -2.5.

Dynamic strategy for personalized medicine: An application to metastatic breast cancer

We compare methods to develop an adaptive strategy for therapy choice in a class of breast cancer patients, as an example of approaches to personalize therapies for individual characteristics and each patient's response to therapy. Our model maintains a Markov belief about the effectiveness of the different therapies and updates it as therapies are administered and tumor images are observed, reflecting tumor response. We compare three different approximate methods to solve our analytical model against standard medical practice and show significant potential benefit of the computed dynamic strategies to limit tumor growth and to reduce the number of time periods patients are given chemotherapy, with its attendant side effects.

Perceived barriers to treatment predict adherence to aromatase inhibitors among breast cancer survivors

BACKGROUND

Although poor adherence to hormonal therapies such as aromatase inhibitors (AIs) is widely documented, to the authors' knowledge less is known regarding whether health beliefs predict treatment nonadherence. The objective of the current study was to evaluate the relationship between health beliefs (perceived susceptibility to breast cancer, perceived benefits of AI treatment, and perceived barriers to AI treatment) and adherence to AIs.

METHODS

Postmenopausal women with early-stage, estrogen receptor-positive breast cancer who were currently receiving treatment with an AI completed the 3-factor Health Beliefs and Medication Adherence in Breast Cancer scale and questionnaires concerning their demographics and symptoms. Adherence data (treatment gaps and premature discontinuation) were abstracted from participants' medical charts. Logistic regression analyses were conducted to evaluate the relationship between health beliefs and adherence.

RESULTS

Among 437 participants, 93 (21.3%) were nonadherent. Those who perceived greater barriers to their AI treatment were more likely to demonstrate AI nonadherence behaviors by the end of their treatment period compared with those who reported fewer barriers to AI therapy (adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.86 [P = .04]). In contrast, perceived susceptibility to cancer recurrence and perceived benefits of AIs did not appear to predict AI adherence. Minority individuals were found to have lower perceived susceptibility to breast cancer recurrence and higher perceived barriers to AI treatment (P<.05 for both).

CONCLUSIONS

Greater perceived barriers appeared to predict nonadherence to AIs. Interventions addressing women's negative beliefs regarding the challenges of AI treatment are needed to help optimize adherence in survivors of breast cancer. Cancer 2017;169-176. © 2016 American Cancer Society.

Switching between endocrine therapies for primary breast cancer: Frequency and timing in Australian clinical practice

AIMS

To determine the frequency, timing and patterns of endocrine therapy switching in Australian practice for postmenopausal women with primary breast cancer.

METHODS

We identified postmenopausal women in a population-based cohort commencing endocrine therapy for invasive primary breast cancer between December 2005 and December 2008 (n = 645). Individual-level administrative health records and self-report data were used to determine women's demographic and clinical characteristics, including preexisting and newly-treated comorbidities, and switches in endocrine therapy. Time to therapy switching was calculated. Chi-square tests compared the characteristics of women who did and did not switch, and those switching within 2 years or after 2 years of commencing therapy.

RESULTS

Twenty-eight percent of women switched from their initial endocrine therapy, most commonly from tamoxifen to anastrozole, or the converse. A small number of anastrozole-to-exemestane and letrozole-to-exemestane switches were observed (n = 19). Most women (>80%) who switched therapies did not have newly-treated comorbidities. Few women (<5%) switched before completing 2 years of therapy, but these women were significantly more likely to have preexisting antidepressant use than women switching later (43% vs 23%, P = 0.048) and remained on the subsequent therapy for less time (6 months vs 2.7 years, P < 0.001).

CONCLUSIONS

Approximately one-quarter of postmenopausal women with primary breast cancer switched endocrine therapies. The findings suggest that the majority of switching in Australian practice was planned; occurring after 2-3 years of, not precipitated by comorbidity, and in a sequence supported by trial evidence. Early switching, however, was associated with preexisting depression and appeared to be a marker of poor persistence.

Need for Weight Management among Postmenopausal Early Breast Cancer Patients Receiving Adjuvant Endocrine Therapy

Increasingly effective adjuvant therapies mean that the prognosis for postmenopausal women with breast cancer has never been better. Weight problems are common among breast cancer patients and worsen due to the impact of diagnosis and treatment. Recent studies have linked excess weight with the risk of recurrence of breast cancer among premenopausal women. While general obesity (body mass index) does not appear to influence the already much improved prognosis for postmenopausal women, there is some evidence that limiting central obesity and improving insulin resistance may improve survival. The focus of attention for postmenopausal breast cancer survivors is also shifting to consider the mortality and morbidity from other weight-related cancers and noncancer causes, such as cardiovascular disease, making weight control a potentially important adjunct to endocrine therapy. This paper outlines the rationale and optimal design for effective weight management strategies among postmenopausal breast cancer patients receiving endocrine therapy.

Advances in the Adjuvant and Neoadjuvant Treatment of Breast Cancer

Several advances in the adjuvant systemic therapy of primary breast cancer have occurred in the last decade and contributed to a decline in disease-related mortality. These include the introduction of aromatase inhibitors, new chemotherapy agents, and the novel antibody trastuzumab. New supportive treatments, such as growth factors, have contributed to the optimization of chemotherapy dose and schedule, and have improved the efficacy and safety of the treatment. In this review we will outline some of the recent advances in the adjuvant and neoadjuvant treatment of breast cancer. We will also discuss ongoing and proposed clinical trials.

Perceived barriers to treatment predict adherence to aromatase inhibitors among breast cancer survivors

BACKGROUND

Although poor adherence to hormonal therapies such as aromatase inhibitors (AIs) is widely documented, to the authors' knowledge less is known regarding whether health beliefs predict treatment nonadherence. The objective of the current study was to evaluate the relationship between health beliefs (perceived susceptibility to breast cancer, perceived benefits of AI treatment, and perceived barriers to AI treatment) and adherence to AIs.

METHODS

Postmenopausal women with early-stage, estrogen receptor-positive breast cancer who were currently receiving treatment with an AI completed the 3-factor Health Beliefs and Medication Adherence in Breast Cancer scale and questionnaires concerning their demographics and symptoms. Adherence data (treatment gaps and premature discontinuation) were abstracted from participants' medical charts. Logistic regression analyses were conducted to evaluate the relationship between health beliefs and adherence.

RESULTS

Among 437 participants, 93 (21.3%) were nonadherent. Those who perceived greater barriers to their AI treatment were more likely to demonstrate AI nonadherence behaviors by the end of their treatment period compared with those who reported fewer barriers to AI therapy (adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.86 [P = .04]). In contrast, perceived susceptibility to cancer recurrence and perceived benefits of AIs did not appear to predict AI adherence. Minority individuals were found to have lower perceived susceptibility to breast cancer recurrence and higher perceived barriers to AI treatment (P<.05 for both).

CONCLUSIONS

Greater perceived barriers appeared to predict nonadherence to AIs. Interventions addressing women's negative beliefs regarding the challenges of AI treatment are needed to help optimize adherence in survivors of breast cancer. Cancer 2017;169-176. © 2016 American Cancer Society.

Controversies in adjuvant endocrine therapy for breast cancer

Adjuvant endocrine therapy for early-stage breast cancer has had the single biggest impact on improving survival from the disease-with tamoxifen alone contributing to saving many thousands of lives. In postmenopausal women, additional progress has been made by the incorporation of aromatase inhibitors into the treatment of early-stage, estrogen receptor (ER)-positive breast cancer, as several large well-conducted trials have established either "up-front" or "switch" strategies that are now widely used. To date, both have been shown to be beneficial when compared with tamoxifen alone, although controversy exists as to which approach is superior. Increasingly, extended adjuvant therapy is being considered, as "longer may be better" for some women who have an ongoing risk of recurrence beyond 5 years. However, controversy remains as to how long adjuvant endocrine therapy should be given for; in clinical practice, clinicians balance the level of risk for individual patients versus any ongoing toxicity concerns. For premenopausal women, with ER-positive breast cancer, tamoxifen remains the gold standard with uncertainty in the added overall benefit of ovarian suppression. Important clinical trials have recently been completed that may help answers this question, including whether complete estrogen deprivation using a luteinizing hormone releasing hormone (LHRH) agonist plus aromatase inhibitors (AIs) is of added benefit. In recent years, molecular profiling of ER-positive breast cancer has started to distinguish those women with a low risk of recurrence on endocrine therapy who may not need chemotherapy. Thus, with more therapy options and greater tumour stratification, modern, adjuvant endocrine therapy is becoming increasingly personalised to suit each individual patient's risk.

The molecular, cellular and clinical consequences of targeting the estrogen receptor following estrogen deprivation therapy

During the past 20 years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed "morning after pill", was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite "antiestrogen" resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women's health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term hormone replacement therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells.

The influence of genetic polymorphisms on the efficacy and side effects of anastrozole in postmenopausal breast cancer patients

Breast cancer is a common cause of cancer mortality among women. Several genetic factors have been implicated in its development. Current treatment guidelines for estrogen receptor-positive breast cancer recommend that anastrozole [or any of the other two aromatase inhibitors (letrozole and exemestane)] is used as an alternative to tamoxifen or following several years of tamoxifen treatment. Nevertheless, this approach is still associated with many challenges, ranging from the recurrence of breast cancer to considerable interindividual variability in the tolerability of anastrozole, which may cause adverse effects, such as musculoskeletal symptoms, and lead to the withdrawal of many patients from treatment. Variabilities in the genes encoding the drug target (aromatase) or its metabolizing enzymes (CYP3A and UGT1A) contribute toward the interindividual variability in anastrozole's pharmacokinetics and/or pharmacodynamics. This paper reviews the role of genetic polymorphisms of CYP19A1, CYP3A4, and UGT1A4 in the responses of female hormone receptor-positive postmenopausal breast cancer patients to anastrozole. Many reviews in the literature have suggested that the study of functional polymorphisms and investigation of relevant genetic markers may provide valuable information in predicting responses to anastrozole in terms of its therapeutic and adverse effects. Nevertheless, more studies are required before the knowledge of its pharmacogenomics can be applied to the individualization of treatment to ensure that patients receive the maximum benefits. Therefore, future analyses, including but not limited to genome-wide association studies, are encouraged to address some of the gray areas in the pharmacogenomics of anastrozole therapy in postmenopausal breast cancer cases; this will help in providing guidance for future pharmacogenomics protocols when anastrozole is utilized in patients' management.

Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials

BACKGROUND

The optimal ways of using aromatase inhibitors or tamoxifen as endocrine treatment for early breast cancer remains uncertain.

METHODS

We undertook meta-analyses of individual data on 31,920 postmenopausal women with oestrogen-receptor-positive early breast cancer in the randomised trials of 5 years of aromatase inhibitor versus 5 years of tamoxifen; of 5 years of aromatase inhibitor versus 2-3 years of tamoxifen then aromatase inhibitor to year 5; and of 2-3 years of tamoxifen then aromatase inhibitor to year 5 versus 5 years of tamoxifen. Primary outcomes were any recurrence of breast cancer, breast cancer mortality, death without recurrence, and all-cause mortality. Intention-to-treat log-rank analyses, stratified by age, nodal status, and trial, yielded aromatase inhibitor versus tamoxifen first-event rate ratios (RRs).

FINDINGS

In the comparison of 5 years of aromatase inhibitor versus 5 years of tamoxifen, recurrence RRs favoured aromatase inhibitors significantly during years 0-1 (RR 0·64, 95% CI 0·52-0·78) and 2-4 (RR 0·80, 0·68-0·93), and non-significantly thereafter. 10-year breast cancer mortality was lower with aromatase inhibitors than tamoxifen (12·1% vs 14·2%; RR 0·85, 0·75-0·96; 2p=0·009). In the comparison of 5 years of aromatase inhibitor versus 2-3 years of tamoxifen then aromatase inhibitor to year 5, recurrence RRs favoured aromatase inhibitors significantly during years 0-1 (RR 0·74, 0·62-0·89) but not while both groups received aromatase inhibitors during years 2-4, or thereafter; overall in these trials, there were fewer recurrences with 5 years of aromatase inhibitors than with tamoxifen then aromatase inhibitors (RR 0·90, 0·81-0·99; 2p=0·045), though the breast cancer mortality reduction was not significant (RR 0·89, 0·78-1·03; 2p=0·11). In the comparison of 2-3 years of tamoxifen then aromatase inhibitor to year 5 versus 5 years of tamoxifen, recurrence RRs favoured aromatase inhibitors significantly during years 2-4 (RR 0·56, 0·46-0·67) but not subsequently, and 10-year breast cancer mortality was lower with switching to aromatase inhibitors than with remaining on tamoxifen (8·7% vs 10·1%; 2p=0·015). Aggregating all three types of comparison, recurrence RRs favoured aromatase inhibitors during periods when treatments differed (RR 0·70, 0·64-0·77), but not significantly thereafter (RR 0·93, 0·86-1·01; 2p=0·08). Breast cancer mortality was reduced both while treatments differed (RR 0·79, 0·67-0·92), and subsequently (RR 0·89, 0·81-0·99), and for all periods combined (RR 0·86, 0·80-0·94; 2p=0·0005). All-cause mortality was also reduced (RR 0·88, 0·82-0·94; 2p=0·0003). RRs differed little by age, body-mass index, stage, grade, progesterone receptor status, or HER2 status. There were fewer endometrial cancers with aromatase inhibitors than tamoxifen (10-year incidence 0·4% vs 1·2%; RR 0·33, 0·21-0·51) but more bone fractures (5-year risk 8·2% vs 5·5%; RR 1·42, 1·28-1·57); non-breast-cancer mortality was similar.

INTERPRETATION

Aromatase inhibitors reduce recurrence rates by about 30% (proportionately) compared with tamoxifen while treatments differ, but not thereafter. 5 years of an aromatase inhibitor reduces 10-year breast cancer mortality rates by about 15% compared with 5 years of tamoxifen, hence by about 40% (proportionately) compared with no endocrine treatment.

FUNDING

Cancer Research UK, Medical Research Council.

Development and validation of the Penn Arthralgia Aging Scale among breast cancer survivors

BACKGROUND

Breast cancer survivors on aromatase inhibitors often experience joint pain as a side effect of their treatment; qualitative investigations suggest that this arthralgia may cause women to feel that they are aging faster than they should be. To facilitate further study of this experience, the Penn Arthralgia Aging Scale (PAAS) was developed. This report describes the development and validation of the PAAS in a racially diverse sample of breast cancer survivors suffering from joint pain.

METHODS

The items of the scale were developed from a content analysis of interviews with patients. The scale was pilot-tested, and modifications were made on the basis of patient feedback. Subsequently, 596 breast cancer survivors who endorsed joint pain completed the 8-item PAAS. The factor structure (with exploratory factor analysis), the internal consistency, and the convergent, divergent, and incremental validity were examined.

RESULTS

The resulting scale had a 1-factor structure with strong internal consistency (Cronbach's α = .94) and demonstrated both convergent and divergent validity: the PAAS was significantly correlated with joint pain severity (rs = 0.55, P < .01) and had a small and nonsignificant correlation with actual age (rs  = -0.07, P = .10). The PAAS was also found to explain incremental variance in anxiety, depression, and pain interference outcomes.

CONCLUSIONS

These findings suggest that the PAAS produces reliable and valid scores that capture perceptions of aging due to arthralgia among breast cancer survivors. With further research, the PAAS may advance our understanding of how perceptions of aging may affect breast cancer survivors' emotional, behavioral, and clinical outcomes.

Association between self-report adherence measures and oestrogen suppression among breast cancer survivors on aromatase inhibitors

PURPOSE

Poor adherence to oral adjuvant hormonal therapy for breast cancer is a common problem, but little is known about the relationship between self-report adherence measures and hormonal suppression. We evaluated the relationship of three self-report measures of medication adherence and oestrogen among patients on aromatase inhibitors (AIs).

MATERIALS AND METHODS

We recruited 235 women with breast cancer who were prescribed AI therapy. Participants self-reported AI adherence by completing the following: (1) a single item asking whether they took an AI in the last month, (2) a modified Morisky Medication Adherence Scale-8 (MMAS-8) and (3) the Visual Analog Scale (VAS). Serum estrone and estradiol were analysed using organic solvent extraction and Celite column partition chromatography, followed by radioimmunoassay.

RESULTS

Ten percent of participants reported they had not taken an AI in the last month and among this group, median estrone (33.2 pg/ml [interquartile range (IQR)=22.3]) and estradiol levels (7.2 pg/mL [IQR=3.3]) were significantly higher than those in participants who reported AI use (median estrone=11.5 pg/mL [IQR=4.9]; median estradiol=3.4 pg/mL [IQR=2.1]; p<0.001). This relationship held when controlling for race and AI drug type.

CONCLUSIONS

A single-item monthly-recall adherence measure for AIs was associated with oestrogen serum levels. This suggests that patient-reported monthly adherence may be a useful measure to identify early non-adherence behaviour and guide interventions to improve patient adherence to hormonal treatment.

Adjuvant aromatase inhibitor therapy in early breast cancer: what factors lead patients to discontinue treatment?

BACKGROUND

Aromatase inhibitors (AIs) are standard hormone therapy (HT) for the adjuvant treatment of postmenopausal endocrine-sensitive early breast cancer. Treatment discontinuation due to toxicity is an important issue that may help clinicians identify effective clinical interventions to allow adequate treatment duration. We reviewed the main reasons for interruption of AIs at our institution from 2006 to 2009.

METHODS

236 patients treated with adjuvant AIs were eligible for analysis. Median age was 64 years (35-89), median follow-up 53 months (6-60). Prior adjuvant chemotherapy was taxane based in 47 patients and anthracycline based in 43 patients. 118 patients had received letrozole, 101 anastrozole, and 17 exemestane.

RESULTS

Twenty-four patients (10%) needed discontinuation of the first AI assigned as a result of toxicity. Grade 2/3 arthralgia was the main reason for discontinuation in 13/24 patients. No differences in the incidence of arthralgia were noted in patients who had received taxanes or anthracyclines. Headache, alopecia, itching, diffuse skin reaction, allergic reaction with hypertensive crisis, xerostomia and xerophthalmia, insomnia and somnolence were the other reasons for discontinuation. In multivariate logistic regression analysis, age (65 years) and HT were independent factors associated with the onset of arthralgia (p = 0.006 and p = 0.008, respectively; OR 2.65, 95% CI 1.32-5.31). Alternative HT (AI or tamoxifen) was offered to patients who wanted or needed to permanently interrupt the ongoing drug.

CONCLUSIONS

In our analysis, 10% of patients discontinued the first AI assigned because of toxicity. Median time course of all adverse events leading to HT discontinuation was 155 days and 135 days for arthralgia. A switch to alternative HT with toxicity monitoring is a recommended option for avoiding premature and permanent interruption of an effective treatment.