Endocrine therapy for breast cancer: assessing an array of women's treatment experiences and perceptions, their perceived self-efficacy and nonadherence

Experiences and management needs of endocrine therapy-related symptoms in patients with breast cancer: a systematic review and qualitative evidence synthesis protocol

INTRODUCTION

Patients with breast cancer and endocrine therapy-related symptoms often experience pain, self-denial, anxiety, fear of recurrence and despair, which can be extremely physically and psychologically traumatising for the patients. Failure to receive effective support and management reduces adherence to medications, leading to a higher risk of relapse and mortality. Clearly, it is paramount to identify what support these patients may need and how to meet their symptom management needs. This paper outlines a protocol to synthesise qualitative evidence on endocrine therapy symptom experiences, management expectations and preferences of patients with breast cancer.

METHODS AND ANALYSIS

The following databases were searched in November 2023 with no date restriction applied: The Cochrane Library, PubMed, Embase, Web of Science, Scopus, CINAHL and OpenGrey. Published studies on qualitative or mixed-method on symptom experiences and management needs during endocrine therapy in patients with breast cancer will be retrieved. We will also search for reference lists and perform a forward citation search. Before inclusion in this review, two reviewers will independently apply the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Qualitative Research to ensure methodological validity. Any disagreements regarding the evaluation of the articles will be resolved through discussion with or by a third reviewer. Data will be extracted using the standardised data extraction tool EndNote20 for unified management, assessment, and review of information. The common sense model of self-regulation will guide data extraction and synthesis. The final synthesised findings will be graded according to the GRADE-CERQual approach to establish confidence.

ETHICS AND DISSEMINATION

This systematic review addressed previously published studies without personally identifiable participant information. Ethical approval from the research committee was not required. The findings of this systematic review will be disseminated to various key stakeholders and published in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42023406987.

Exploring adherence in patients with advanced breast cancer: focus on CDK4/6 inhibitors

Treatment adherence is crucial for optimal outcomes in advanced breast cancer, but can be challenging due to various factors, i.e. patients' attitudes and behavior upon diagnosis, and complex therapies with high adverse effect rates. Our aim was to explore the adherence to oral anticancer medications (OAM) in women with advanced breast cancer, focusing on cyclin-dependent kinase 4 and 6 inhibitors (CDKI), and identify factors associated with the adherence. We conducted a cross-sectional study at the University Hospital Centre Zagreb, Croatia, involving women with stage IV advanced breast cancer receiving OAM. Data collection included a questionnaire assessing socio-demographic and clinical information, Beck Depression Inventory-II for depressive symptoms, Medication Adherence Report Scale (MARS-5) for adherence to OAM, and Beliefs about Medicines Questionnaire. Plasma concentrations of CDKI were confirmed by LC-MS/MS in three randomly selected participants. A total of 89 women were included. The most prescribed OAMs were anti-estrogen (71.3 %) and CDKI (60.9 %). MARS-5 scores (mean: 24.1 ± 1.6) correlated with CDKI plasma concentrations. Forgetfulness was the primary reason for non-adherence (25.9 %). Women receiving CDKI (p = 0.018), without depressive symptomatology (p = 0.043), and with more positive beliefs about medicines were more adherent (p < 0.05). This study enhances understanding of medication adherence in advanced breast cancer and identifies influential factors.

Investigation of Factors Affecting Adherence to Adjuvant Hormone Therapy in Early-Stage Breast Cancer Patients: A Comprehensive Systematic Review

PURPOSE

Adherence and persistence to adjuvant hormone therapy (AHT) are seldom maintained among early-stage hormone receptor-positive breast cancer (BC) survivors, despite the significant clinical benefits of long-term AHT. As the factors influencing adherence to AHT remain unclear, this study aimed to comprehensively identify such factors and classify them into specific dimensions.

METHODS

PubMed, Cochrane Library, Embase, PsycINFO, and CINAHL were searched for qualified articles. The search mainly focused on three components: early-stage (0-III) BC, oral AHT administration, and adherence to AHT, with keywords derived from MeSH and entry terms. The factors identified were then classified into six categories based on a modified WHO multidimensional model.

RESULTS

Overall, 146 studies were included; the median sample size was 651 (range, 31-40,009), and the mean age of the population was 61.5 years (standard deviation, 8.3 years). Patient- and therapy-related factors were the most frequently investigated factors. Necessity/concern beliefs and self-efficacy among patient-related factors were consistently related to better adherence than depression. Although drug side effects and medication use cannot be modified easily, a refined prescription strategy for the initiation and switching of AHT is likely to increase adherence levels.

CONCLUSION

An effective psychological program that encourages positive views and beliefs about medication and management strategies for each therapy may be necessary to improve adherence to AHT. Social support and a sense of belonging can be enhanced through community participation and social media for better adherence to AHT. Patient-centered communication and appropriate recommendations by physicians may be attributable to better adherence outcomes. Findings from systematically organized factors that influence adherence to AHT may contribute to the establishment of intervention strategies to benefit patients with early-stage BC to achieve optimal health.

Treatment-related side effects among Hispanic and non-Hispanic white long-term breast cancer survivors by tamoxifen use and duration

PURPOSE

To determine the associations between ethnicity, age at diagnosis, obesity, multimorbidity, and odds of experiencing breast cancer (BC) treatment-related side effects among long-term Hispanic and non-Hispanic white (NHW) survivors from New Mexico and explore differences by tamoxifen use.

METHODS

Lifestyle and clinical information including self-reported tamoxifen use and presence of treatment- related side effects were collected at follow-up interviews (12-15 years) for 194 BC survivors. Multivariable logistic regression models were used to examine associations between predictors and odds of experiencing side effects overall and by tamoxifen use.

RESULTS

Women ranged in age at diagnosis (30-74, M = 49.3, SD = 9.37), most were NHW (65.4%) and had in-situ or localized BC (63.4%). Less than half reportedly used tamoxifen (44.3%), of which 59.3% reported using > 5 years. Overall, survivors who were overweight/obese at follow-up were 5.42 times more likely to experience treatment-related pain (95% CI 1.40-21.0) compared to normal weight survivors. Survivors with multimorbidity, compared to survivors without, were more likely to report treatment-related sexual health issues (aOR 6.90, 95% CI 1.43-33.2) and poorer mental health (aOR 4.51, 95% CI 1.06-19.1). The statistical interactions between ethnicity and overweight/obese with tamoxifen use were significant (p-interaction < 0.05) for treatment-related sexual health issues.

CONCLUSION

Our results demonstrate that survivors with overweightness/obesity or multimorbidity may be more likely to experience BC treatment-related side effects. Tamoxifen use modifies associations between ethnicity, being overweight/obese, and sexual health issues following treatment. The likelihood of experiencing treatment-related side effects were more favorable for those on tamoxifen or those who had used tamoxifen for longer durations. These findings highlight the importance of fostering side effect awareness and applying appropriate interventions to assist with disease management throughout BC survivorship care.

Refining and optimising a behavioural intervention to support endocrine therapy adherence (ROSETA) in UK women with breast cancer: protocol for a pilot fractional factorial trial

INTRODUCTION

Women with breast cancer who do not adhere to adjuvant endocrine therapy (AET) have increased risks of mortality and recurrence. There are multiple barriers to AET adherence, including medication side-effects, beliefs about medication, memory and psychological distress. We developed four intervention components, each targeting a different barrier. This pilot trial is part of the preparation phase of the Multiphase Optimisation Strategy, and aims to establish key trial parameters, establish intervention component adherence, establish availability and feasibility of outcome and process data, estimate variability in planned outcome measures and estimate cost of developing and delivering each intervention component.

METHODS AND ANALYSIS

The four intervention components are as follows: short message service text reminders (target: memory); a written information leaflet (target: medication beliefs); a guided self-help Acceptance and Commitment Therapy programme (target: psychological flexibility to reduce distress) and a self-management website (target: side-effect management). To evaluate the feasibility of recruitment, acceptability of the intervention components and the availability of outcome data, we will conduct a multisite, exploratory pilot trial using a 2^4-1 fractional factorial design, with a nested process evaluation. We will randomise 80 women with early-stage breast cancer who have been prescribed AET to one of eight experimental conditions. This will determine the combination of intervention components they receive, ranging from zero to four, with all conditions receiving usual care. Key outcomes of interest include medication adherence and quality of life. Progression to the optimisation phase will be based on predefined criteria for consent rates, patient adherence to intervention components and availability of medication adherence data.

ETHICS AND DISSEMINATION

The study was reviewed by the Wales Research Authority Research Ethics Committee 3 (21/WA/0322). Written informed consent will be obtained from all patients before randomisation. The results of this trial will be disseminated in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRTCN10487576.

Association of Adherence to Endocrine Therapy Among Patients With Breast Cancer and Potential Drug-Drug Interactions

IMPORTANCE

Suboptimal adherence to endocrine therapy (ET) among patients with hormone-receptor-positive breast cancer significantly affects survival outcomes and is associated with higher hospitalization rates and health care costs. Weak adherence to long-term treatments has multiple determinants, including disease characteristics, treatment adverse effects, and patients' attributes, such as age and comorbidities.

OBJECTIVE

To examine whether potential drug-drug interactions (PDDI) with tamoxifen or aromatase inhibitor were associated with adherence to ET in patients with early and advanced breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used anonymized health record data of women with breast cancer who received ET in a private observational primary care database. Patients eligible for analysis included women aged 18 years or older who had a reported diagnosis of breast cancer and received ET with tamoxifen or aromatase inhibitor between 1994 and 2021. Data were analyzed 2021.

EXPOSURES

Adherence to ET during a given year was defined by a medication possession ratio of 80% or greater over 1-year prescription periods. PDDI were categorized into absent, minor (a combination to take into account), moderate (combination requiring precautions for use), major (combination not recommended), and contraindicated according to guidelines in the Claude Bernard Drug Database.

MAIN OUTCOMES AND MEASURES

We used regression models to estimate odds ratios (ORs) and 95% CIs for the associations between adherence and age, baseline comorbidities, PDDI, and adherence to ET during the previous year.

RESULTS

A total of 10 863 patients who were prescribed ET for breast cancer were eligible for the analysis (age 70 years or older, 3509 patients [32.3%]). In the tamoxifen cohort (3564 patients), PDDI were reported in 497 of 3670 patients (13.5%) at baseline (moderate, 254 patients [51.1%]; major, 227 patients [45.7%]), 2047 of 4831 patients (42.4%) at year 1, 1127 of 2751 patients (41.0%) at year 2, 761 of 1861 patients (40.9%) at year 3, 376 of 1058 patients (35.5%) at year 4, and 201 of 593 patients (33.9%) at year 5. In the aromatase inhibitor cohort (7299 patients), PDDI were reported in 592 of 7437 patients (8.0%) at baseline (moderate in 588 of 592 patients [99.3%]), which reached 2875 of 9031 patients (31.8%) at year 1 and ranged between 31.4% (1802 of 5730 patients in year 2) and 32.8% (791 of 2411 in year 4) throughout the study period. No association between adherence and PDDI was found in the tamoxifen (OR, 0.99; 95% CI, 0.91-1.08) or aromatase inhibitor (OR, 1.05; 95% CI, 0.95-1.15) cohort.

CONCLUSIONS AND RELEVANCE

In this cohort of patients with hormone-receptor-positive breast cancer, PDDI with tamoxifen and aromatase inhibitors were not associated with adherence to ET.

Trajectories of neuropsychological symptom burden in postmenopausal women prescribed anastrozole for early-stage breast cancer

PURPOSE

Aromatase inhibitors (AIs) prolong survival for postmenopausal women with hormone receptor-positive breast cancer (HR + BC) but also burden patients with symptoms, a major reason for suboptimal AI adherence. This study characterizes inter-relationships among symptom measures; describes neuropsychological symptom burden trajectories; and identifies trajectory group membership predictors for postmenopausal women prescribed anastrozole for HR + BC.

METHODS

This study utilized prospectively collected data from a cohort study. Relationships among various self-reported symptom measures were examined followed by a factor analysis to reduce data redundancy before trajectory analysis. Four neuropsychological scales/subscales were rescaled (range 0-100) and averaged into a neuropsychological symptom burden (NSB) score, where higher scores indicated greater symptom burden. Group-based trajectory modeling characterized NSB trajectories. Trajectory group membership predictors were identified using multinomial logistic regression.

RESULTS

Women (N = 360) averaged 61 years old, were mostly White, and diagnosed with stage I HR + BC. Several measures were correlated temporally but four neuropsychological measures had strong correlations and dimensional loadings. These four measures, combined for the composite NSB, averaged (mean ± standard deviation) 17.4 ± 12.9, 18.0 ± 12.7, 19.5 ± 12.8, and 19.8 ± 13.0 at pre-anastrozole, 6, 12, and 18 months post-initiation, respectively. However, the analysis revealed five NSB trajectories-low-stable, low-increasing, moderate-stable, high-stable, and high-increasing. Younger age and baseline medication categories (pre-anastrozole), including anti-depressants, analgesics, anti-anxiety, and no calcium/vitamin D, predicted the higher NSB trajectories.

CONCLUSION

This study found relationships among neuropsychological symptom measures and distinct trajectories of self-reported NSB with pre-anastrozole predictors. Identifying symptom trajectories and their predictors at pre-anastrozole may inform supportive care strategies via symptom management interventions to optimize adherence for women with HR + BC.

Adherence to Adjuvant Therapy in Patients with Resected Melanoma: An Application of the Theory of Planned Behavior

INTRODUCTION

Adherence to adjuvant therapy is crucial for effective disease management in patients with resected melanoma. This study assessed patient-reported adherence to adjuvant therapy and identified behavioral/belief constructs associated with adherence in patients with resected melanoma.

METHODS

Patients with resected stage III/IV melanoma were recruited through the Melanoma Research Foundation and a patient panel to complete an online survey. Patient characteristics, medical history, and adherence to therapy were captured. In accordance with the theory of planned behavior (TPB), the survey measured behavioral, normative, and control beliefs, and intention to adhere to therapy. Structural equation modeling (SEM) examined their relationships with adherence.

RESULTS

Among all patients who received adjuvant therapy and completed the survey (n = 184), 69% received intravenous and 31% received oral therapy; the majority (85.3%) were somewhat involved in deciding to start therapy. Mean age was 45 years, 44% of patients were female, and 83% had stage III/IV disease at diagnosis. Patients had a mean disease duration of 1.5 years, a time since complete resection of 10 months, and an adjuvant therapy duration of 8 months. Adherence to adjuvant therapy was high overall and higher with intravenous than with oral therapy (98.4% versus 91.2%, P = 0.002). All underlying TPB constructs were significant in the SEM model, which explained 60.3% of the variance in intention to adhere. Control beliefs had the strongest association with intention to adhere (standardized estimate = 0.47, P < 0.001) and intravenous therapy was associated with greater adherence than oral therapy (standardized estimate = 0.26, P < 0.001).

CONCLUSIONS

This study found that patients with resected melanoma are highly engaged in the decision to initiate systemic adjuvant therapy, with an overall high adherence rate to prescribed adjuvant treatment. Enhancing patients' view of their capability to adhere to treatments may further improve the adherence rate to melanoma adjuvant therapy.

Supporting adjuvant endocrine therapy adherence in women with breast cancer: the development of a complex behavioural intervention using Intervention Mapping guided by the Multiphase Optimisation Strategy

BACKGROUND

Adjuvant endocrine therapy (AET) reduces the risk of breast cancer recurrence and mortality. However, up to three-quarters of women with breast cancer do not take AET as prescribed. Existing interventions to support adherence to AET have largely been unsuccessful, and have not focused on the most salient barriers to adherence. This paper describes the process of developing four theory-based intervention components to support adherence to AET. Our aim is to provide an exemplar of intervention development using Intervention Mapping (IM) with guidance from the Multiphase Optimisation Strategy (MOST).

METHODS

Iterative development followed the six-stage IM framework with stakeholder involvement. Stage 1 involved a literature review of barriers to adherence and existing interventions, which informed the intervention objectives outlined in Stage 2. Stage 3 identified relevant theoretical considerations and practical strategies for supporting adherence. Stage 4 used information from Stages 1-3 to develop the intervention components. Stages 1-4 informed a conceptual model for the intervention package. Stages 5 and 6 detailed implementation considerations and evaluation plans for the intervention package, respectively.

RESULTS

The final intervention package comprised four individual intervention components: Short Message Service to encourage habitual behaviours surrounding medication taking; an information leaflet to target unhelpful beliefs about AET; remotely delivered Acceptance and Commitment Therapy-based guided self-help to reduce psychological distress; and a website to support self-management of AET side-effects. Considerations for implementation within the NHS, including cost, timing and mode of delivery were outlined, with explanation as to how using MOST can aid this. We detail our plans for the final stage of IM which involve feasibility testing. This involved planning an external exploratory pilot trial using a 2^4-1 fractional factorial design, and a process evaluation to assess acceptability and fidelity of intervention components.

CONCLUSIONS

We have described a systematic and logical approach for developing a theoretically informed intervention package to support medication adherence in women with breast cancer using AET. Further research to optimise the intervention package, guided by MOST, has the potential to lead to more effective, efficient and scalable interventions.

The impact of medication side effects on adherence and persistence to hormone therapy in breast cancer survivors: A quantitative systematic review

BACKGROUND

Hormone Therapy (HT) is recommended for most women with HR-positive primary breast cancer. When taken as intended, HT reduces breast cancer recurrence by 40% and mortality by one-third. The recommended duration of treatment ranges from 5 to 10 years depending on risk of recurrence and the specific HT regimen. However, recent data indicates that rates of HT non-adherence are high and research suggests this may be due to the impact of HT side effects. The contribution of side effects to non-adherence and non-persistence behaviours has rarely been systematically explored, thereby hindering the implementation of targeted intervention strategies. Our aim is to identify, evaluate and summarise the relationship between HT side effects and patterns of adherence and persistence.

METHODS

Electronic searches were conducted from inception and were completed by September 2021, utilising Cochrane CENTRAL, Medline, Embase, Web of Science and PsycINFO databases. Searches included a combination of terms related to breast cancer, adherence, hormone therapy and side effects.

RESULTS

Sixty-two eligible papers were identified and study quality varied by study type. Most observational and cross-sectional studies were rated good quality, whereas most controlled intervention studies were rated fair quality. Three studies were rated poor quality. The most frequently measured side effects were pain, low mood, hot flashes, insomnia, anxiety, fatigue, weight gain, concentration/memory problems.

CONCLUSIONS

This review identified a lack of consistency in the measurement of adherence and the definition of persistence across studies. The instruments used to measure side effects also varied significantly. This variation and lack of consistency makes it difficult to evaluate and summarise the role of HT side effects in HT adherence and persistence behaviour.

An intervention mapping-based support program that empowers patients with endocrine therapy management

BACKGROUND

For women diagnosed with hormone-receptor-positive breast cancer, endocrine therapy (ET) is recommended. Patients experience diverse side effects, and difficulties in managing these side effects have been identified as obstacles for treatment continuation. The aim of this study was to describe the development of a support program for patients prescribed ET.

METHODS

Intervention mapping (IM) a comprehensive theory-based approach was used in the support program development. A participatory design was used and four advisory groups was formed including both patients and healthcare professionals.

RESULTS

This study employed the systematic stages of IM to develop a theory-based support program with the goal to empower patients prescribed ET to manage ETrelated symptoms and problems, and to illuminate the healthcare structure. The needs assessment identified three performance objectives: (1) Patients have knowledge of and understand their symptoms and their management strategies. (2) Patients have the knowledge and confidence to express their care needs and to ask for guidance from healthcare professionals. (3) Patients are active in and lead their healthcare process.

CONCLUSION

This is a systematic developed model, built upon aspects of ET both from a patient´ perspective as well as from healthcare professionals' perspectives.

Escala de Adherencia Terapéutica para tratamiento de Cáncer de Mama (EAT-CaMa): Una evaluación multidimensional

Introducción: La adherencia terapéutica es un aspecto clave en el éxito del tratamiento en oncología, sin embargo, su medición es un reto dentro del sistema de salud. Asimismo, no se tienen escalas especificas validas o construidas para evaluar la adherencia en pacientes con cáncer de mama. Objetivo: Determinar las propiedades psicométricas de la Escala de Adherencia Terapéutica al Cáncer de Mama (EAT-CaMa). Método: Se empleó un diseño no experimental, instrumental con un muestreo no probabilístico. Se incluyeron 189 participantes con diagnóstico de CaMa entre 21 y 84 años. Análisis estadísticos: Se realizó un análisis factorial exploratorio y consistencia interna. Resultados: La EATCaMa de 27 reactivos, obtuvo una consistencia interna global α= 0,81 y una varianza explicada del 64%. Se identificaron factores de autoeficacia y comunicación médico paciente, así como varios indicadores. Conclusión: El EAT-CaMa es un instrumento breve, válido y confiable para la evaluación multidimensional de la adherencia al tratamiento en población con CaMa. La estructura factorial identificada corrobora componentes reportados en la literatura y clínicamente relevantes. Se recomienda su uso en la atención clínica (inicio y seguimiento del tratamiento) y en investigación.

Effect of a Smart Pill Bottle Reminder Intervention on Medication Adherence, Self-efficacy, and Depression in Breast Cancer Survivors

BACKGROUND

Globally, breast cancer has been identified as the most common cancer among women. The clinical efficacy of adjuvant oral antiestrogen therapy-including tamoxifen and aromatase inhibitors-has been proven to be clinically efficacious for breast cancer survivors. However, medication adherence for these therapies remains suboptimal among breast cancer survivors.

OBJECTIVE

The aim of this study was to evaluate the effect of a reminder intervention-a smart pill bottle paired with the Pillsy mobile application-on medication adherence, medication self-efficacy, and depression, among breast cancer survivors who were undergoing oral antiestrogen therapy.

METHODS

This study is a randomized controlled trial. Sixty-one women were allocated to an experimental group (n = 31) and the control group (n = 30). The experimental group received the reminder intervention of a smart pill bottle for 4 weeks. Study outcomes were identified as medication adherence, medication self-efficacy, and depression.

RESULTS

Fifty-seven women completed the follow-up measurement. Significant differences in favor of the experimental group were noted for medication adherence ( P = .004) and medication self-efficacy ( P = .004). There was no statistically significant difference between the 2 groups with regard to depression ( P = .057).

CONCLUSIONS

Reminder intervention using smart pill bottles was effective in improving medication adherence and medication self-efficacy among breast cancer survivors undergoing oral antiestrogen therapy.

IMPLICATIONS FOR PRACTICE

A smart pill bottle method of intervention can be a useful reminder strategy to improve medication adherence among breast cancer survivors.

Adherence to Adjuvant Tamoxifen in Mexican Young Women with Breast Cancer

BACKGROUND

Breast cancer (BC) in young women is characterized by an unfavorable prognosis in hormone receptor-positive/HER2-negative tumors, which may be explained by low rates of tamoxifen adherence. In Mexico, up to 14% of all BC diagnoses occur in young women and no data on tamoxifen adherence has been reported.

OBJECTIVE

To estimate the rate of adherence to adjuvant tamoxifen in Mexican young women with BC (YWBC).

METHODS

A cross-sectional survey was conducted at the National Cancer Institute in Mexico City, among YWBC (≤40 years at diagnosis) receiving adjuvant tamoxifen. Adherence was measured subjectively, through self-reported surveys, and objectively, through medication possession ratio (MPR). Descriptive statistics were used to analyze sociodemographic characteristics. To compare associations between patients' characteristics and adherence, Chi-square test was used for categorical variables and Student's t-test or Mann-Whitney U-test for quantitative variables.

RESULTS

A total of 141 YWBC receiving adjuvant tamoxifen were included. Regarding subjective adherence, 95% expressed taking tamoxifen regularly, 70% reported missing 0 doses in the past 30 days, and 71.6% reported having adverse effects. Regarding objective adherence, 74.8% of patients had an MPR ≥80%. The association between subjective and objective adherence was statistically significant (p = 0.004). Subjective adherence was associated with not skipping tamoxifen doses when feeling worse. Objective adherence was associated with having a stable job, not skipping tamoxifen doses when feeling worse, taking additional medications, and time on tamoxifen treatment. Fifty-six percent considered the information on tamoxifen to be insufficient and 37% not understandable.

CONCLUSION

In our study, high subjective and objective adherence rates to adjuvant tamoxifen were reported, although an important proportion of women reported high rates of adverse effects and not fully understanding the benefits of tamoxifen. Strategies to increase tamoxifen adherence may be even more important now that longer durations of treatment or further ovarian function suppression have become the standard of care in YWBC.

Potentially Modifiable Factors Associated with Adherence to Adjuvant Endocrine Therapy among Breast Cancer Survivors: A Systematic Review

Adjuvant endocrine therapy (AET) reduces risk of breast cancer recurrence. However, suboptimal adherence and persistence to AET remain important clinical issues. Understanding factors associated with adherence may help inform efforts to improve use of AET as prescribed. The present systematic review examined potentially modifiable factors associated with adherence to AET in accordance with PRISMA guidelines (PROSPERO registration ID: CRD42019124200). All studies were included, whether factors were significantly associated with adherence or results were null. This review also accounted for the frequency with which a potentially modifiable factor was examined and whether univariate or multivariate models were used. This review also examined whether methodological or sample characteristics were associated with the likelihood of a factor being associated with AET adherence. A total of 68 articles were included. Potentially modifiable factors were grouped into six categories: side effects, attitudes toward AET, psychological factors, healthcare provider-related factors, sociocultural factors, and general/quality of life factors. Side effects were less likely to be associated with adherence in studies with retrospective or cross-sectional than prospective designs. Self-efficacy (psychological factor) and positive decisional balance (attitude toward AET) were the only potentially modifiable factors examined ≥10 times and associated with adherence or persistence ≥75% of the time in both univariate and multivariate models. Self-efficacy and decisional balance (i.e., weight of pros vs. cons) were the potentially modifiable factors most consistently associated with adherence, and hence may be worth focusing on as targets for interventions to improve AET adherence among breast cancer survivors.

Development of a self-management intervention to improve tamoxifen adherence in breast cancer survivors using an Intervention Mapping framework

OBJECTIVE

Up to 50% of women prescribed tamoxifen do not take it as prescribed for the full duration, which increases risk of recurrence and mortality. The current paper describes the development of a self-management intervention aiming to improve adherence in breast cancer survivors taking tamoxifen.

METHODS

The intervention was developed following an Intervention Mapping approach. The content of the intervention was determined by theories of health behaviour and empirical evidence. Development was an iterative process involving input from expert researchers, clinicians and patient representatives.

RESULTS

The intervention was designed to improve both intentional and unintentional non-adherence. Key features included modifying unhelpful illness and treatment beliefs, improving confidence for coping with side effects and developing strategies for remembering to take tamoxifen.

CONCLUSION

Intervention Mapping proved a useful tool for developing an intervention which is grounded in theory and empirical evidence. The intervention has the potential to improve adherence in breast cancer survivors but needs to be trialled before the effectiveness of the intervention can be determined.

"It is not just any pill"-Women's experiences of endocrine therapy after breast cancer surgery

OBJECTIVE

For patients diagnosed with hormone-receptor-positive breast cancer, endocrine therapy (ET) is usually prescribed to reduce recurrence and mortality rates. Despite the benefits, compliance with treatment varies. The aim of this study was to provide qualitative data about women's experiences with ET after breast cancer surgery.

METHODS

Twenty-five women, treated with Tamoxifen after breast cancer surgery, were interviewed in seven focus groups. Six open-ended questions were used to explore their experiences. The interviews were recorded, transcribed verbatim and analysed using inductive content analysis.

RESULTS

The analysis resulted in three categories that described the women's experiences: the treatment "creates discomfort"; "promotes levels of management"; and "causes feelings of abandonment". Women's experiences of treatment could at first glance be seen as positive, as perceived protection, but after further analysis, a deeper meaning was identified: protection with reservation. When experiencing discomfort, the women tried to manage the situation, although the mode of management sometimes varied. The women reported that they needed support, but when the support did not appear, they felt as though they had been abandoned. Moreover, knowledge about side effects became an obstacle, as it could create fear of more severe symptoms. They also described that their disease was perceived by healthcare professionals as "cancer light".

CONCLUSION

The information needs to be customised specifically to each person.

When patients' invisible work becomes visible: non-adherence and the routine task of pill-taking

While the biographical dimensions of chronic illness have been well researched, the concrete dimensions of patients' work have not been as thoroughly investigated as yet. With the growing concern for self-management, such research would be timely. This study aims to better understand patients' invisible work by highlighting the causes of unintentional non-adherence as well as strategies for adherence. For this purpose, it defines medical treatment adherence as the repetition of the pattern of tasks through which a patient succeeds, in a technical sense, in taking the right medication at the right time, in the right amount, for the right duration. Applying a failure modes and effects analysis approach to 48 semi-structured interviews with Dutch patients, it shows the negative impact of schedule changes, pressure, positioning changes, lack of backup pills and lack of verification tools. Symmetrically, it highlights the role of anchoring, sequencing, positioning, cueing, correcting and verifying. This result points to the need for an analytical approach of patients' work and treatment adherence that would build on the role of routines in organisations and in the workplace.

Applying the theory of planned behavior to examine adjuvant endocrine therapy adherence intentions

OBJECTIVE

Adherence to adjuvant endocrine therapy (AET) in breast cancer survivors is suboptimal. Using the theory of planned behavior (TPB), this study aimed to identify the strongest predictors from the TPB of AET intentions and past behavior and assessed whether ambivalence and anticipatory emotions increased the predictive capacity of TPB.

METHODS

Two hundred eighty women diagnosed with hormone positive (HR+) breast cancer who filled at least one prescription of AET responded to a survey measuring TPB constructs, attitudinal ambivalence, and anticipatory emotions. The outcomes were intentions to adhere to AET and past medication adherence (previous 2 weeks).

RESULTS

The TPB explained 66% of intentions to adhere to AET (P < 0.001). Ambivalence did not improve the TPB model's predictive value. When emotions were included with TPB, the model explained 70% of adherence intentions F_11,226  = 52.84, P < 0.001 (R² _c  = .70). This increase of 4% in predictability was statistically significant (ΔR²  = 0.04), F_{6, 226}  = 7.90, P < 0.001. Women who self-reported nonadherence in the past 2 weeks differed significantly in the TPB variables, ambivalence, and anticipatory emotions from adherent women. Nonadherent participants reported lower-future intentions to adhere F_{1, 236}  = 5.63, P = 0.018.

CONCLUSIONS

Results suggest key concepts, such as anticipatory positive emotions that should be addressed in future interventions to enhance AET adherence and survivorship.

Improving adherence to endocrine hormonal therapy among breast cancer patients: Study protocol for a randomized controlled trial

Adjuvant endocrine hormonal therapy (EHT) is highly effective and appropriate for nearly all breast cancer patients with hormone receptor-positive tumors, which represent 75% of all breast cancer diagnoses. Long-term use of EHT reduces recurrence rates and nearly halves the risk of death during the second decade after diagnosis. Despite the proven benefits, about 33% of women receiving EHT do not take their medication as prescribed. This causes an increase in the risk for recurrence and death.

To promote adherence to EHT among breast cancer patients, this study will develop and pilot-test an intervention consisting of 1) a bilingual, culturally tailored, personalized, interactive smartphone application (app); and 2) support from a patient navigator. The control group will receive usual care. This 2-group randomized control trial will recruit 120 breast cancer patients receiving EHT at the Mays Cancer Center at UT Health San Antonio. The two-year study will have 3-time assessments (baseline, 3 and 6 months).

This theory-based intervention will empower patients' self-monitoring and management. It will facilitate patient education, identification/reporting of side effects, delivery of self-care advice, and simplify communication between the patient and the oncology team. The ultimate goal of this innovative multi-communication intervention is to improve overall survival and life expectancy, enhance quality of life, reduce recurrence, and decrease healthcare cost. The anticipated outcome is a scalable, evidence-based, and easily disseminated intervention with potentially broad use to patients using EHT and other oral anticancer agents.

Racial and geographic disparities in adherence and discontinuation to adjuvant endocrine therapy in Texas Medicaid-insured patients with breast cancer

The purpose of the study is to examine disparities in AET adherence and discontinuation among Texas Medicaid-insured early-stage breast cancer patients. Texas Cancer Registry Medicaid-linked database was used from 2000 to 2007 for breast cancer patients aged 20-64. Multivariable logistic regression was performed to test the association of race/ethnicity and geographic factors with AET adherence and discontinuation. Of the 1240 women with breast cancer, 60.8% of non-Hispanic white vs 46.6% of Black patients were adherent to AET in the first year. After adjusting for confounding, Black patients had lower odds of adherence compared to non-Hispanic white patients (Odds ratio 0.62, 95% CI 0.44-0.87), but they were not more likely to discontinue therapy during the study period. Patients from the Texas/Mexico border had higher odds of adherence compared to other regions (OR 2.32, 95% CI 1.29-4.18). There are substantial racial and geographic disparities in AET adherence and discontinuation among Texas Medicaid-insured women.

Time to treatment and survival in triple negative breast cancer patients receiving trimodality treatment in the United States

BACKGROUND

Time from diagnosis to treatment for breast cancer patients has been linked to outcomes. Our goal was to assess the relationship between survival, time to first treatment (TFT), and time to treatment completion (TTC) in Stage I-III triple negative breast cancer (TNBC) receiving trimodality therapy (surgery, chemotherapy, and radiation).

METHODS

National Cancer Database (NCDB) was queried for TNBC patients diagnosed with Stage I-III disease from 2010 to 2011 who received all treatments (surgery, chemotherapy, radiation) within 18 months of diagnosis. Multivariate analysis controlled for age, stage, operation, neoadjuvant chemotherapy (NAC), and comorbidities.

RESULTS

17,717 women were included. Most had early stage disease (34.1% Stage 1; 48.2% Stage 2) treated with lumpectomy (69.2%) and adjuvant chemotherapy (63.3%). During follow-up (2.8 ± 1.1 years), mortality was 11.4%. TFT was 34.8 days for NAC and 35.6 days for surgery. Multivariate analysis demonstrated no mortality difference when considering TFT in 30 day (p = 0.43) or 6 week (p = 0.91) intervals. When separating into NAC or surgery first, there remained no mortality difference when considering TFT in 30 day (NAC p = 0.96, surgery p = 0.26) or 6 week (NAC p = 0.91, surgery p = 0.91) intervals. Overall, TTC was 9.0 ± 1.8 months. When dividing patients into tertiles by TTC, multivariate analysis demonstrated no survival difference between groups (p = 0.9). There was also no mortality difference for each 30 day increased TTC (p = 0.40).

CONCLUSIONS

In Stage I-III TNBC patients receiving trimodality therapy, TFT (NAC or surgery) and TTC do not impact short-term survival if TTC is <18 months.

Relationships between determinants of adjuvant endocrine therapy adherence in breast cancer

BACKGROUND

Interventions that promote adjuvant endocrine therapy (AET) adherence are critical to improve breast cancer survival. The development of interventions would benefit from a better understanding of the reasons for adherence and the causal relationships of determinants using theoretical or model approaches. The aim of the present study was to identify reasons for AET adherence in breast cancer patients with sequential relationships and inter-relationships.

METHODS

A total of 210 participants with estrogen receptor positive breast cancer who received AET completed a questionnaire assessing demographic/medical, psychological, and endocrine therapy (ET)-specific factors. A descriptive analysis was performed to identify meaningful variables. Selected variables were subjected to hierarchical regression and path analyses. The path model was tested and modified based on the research framework and the results of regression weights and model fit.

RESULTS

Analysis of sequential effects showed that ET-specific factors contributed the largest proportion of variance (13.4%) to predict AET adherence, followed by psychological factors (4.6%) and demographic/medical factors (3.1%). Analysis of inter-relationships showed that demographic/medical factors such as AET regimen type and cancer stage have direct effects on AET adherence, whereas psychological factors contribute indirectly through the mediating effects of ET-specific factors.

CONCLUSION

Assessments and interventions that encompass the patient's medication beliefs, self-efficacy, and depression are needed to promote AET adherence.

Adjuvant endocrine therapy after breast cancer: a qualitative study of factors associated with adherence

INTRODUCTION

Despite evidence of the efficacy of adjuvant endocrine therapy (AET) in reducing the risk of recurrence and mortality after treatment for primary breast cancer, adherence to AET is suboptimal. This study aimed to explore factors that influence adherence and nonadherence to AET following breast cancer to inform the development of supportive interventions.

METHODS

Interviews were conducted with 32 women who had been prescribed AET, 2-4 years following their diagnosis of breast cancer. Both adherers (n=19) and nonadherers (n=13) were recruited. The analysis was conducted using the Framework approach.

RESULTS

Factors associated with adherence were as follows: managing side effects including information and advice on side effects and taking control of side effects, supportive relationships, and personal influences. Factors associated with nonadherence were as follows: burden of side effects, feeling unsupported, concerns about long-term AET use, regaining normality, including valuing the quality of life over length of life, and risk perception.

CONCLUSION

Provision of timely information to prepare women for the potential side effects of AET and education on medication management strategies are needed, including provision of timely and accurate information on the efficacy of AET in reducing breast cancer recurrence and on potential side effects and ways to manage these should they arise. Trust in the doctor-patient relationship and clear patient pathways for bothersome side effects and concerns with AET are important. Training and education on AET for GPs should be considered alongside novel care pathways such as primary care nurse cancer care review and community pharmacist follow-up.

Understanding tamoxifen adherence in women with breast cancer: A qualitative study

OBJECTIVE

Non-adherence to tamoxifen is common in breast cancer survivors and is associated with poor clinical outcomes. This study aimed to understand womens' experiences of taking tamoxifen and to identify factors which may be associated with non-adherence.

DESIGN

A qualitative study using semi-structured interviews.

METHODS

Thirty-two breast cancer survivors who had been prescribed tamoxifen took part in interviews conducted face to face or over the telephone. They were transcribed verbatim and analysed using inductive thematic analysis with elements of grounded theory.

RESULTS

A key theme identified in the data was weighing up costs and benefits of treatment, which resulted in women falling into three groups; tamoxifen is keeping me alive, tamoxifen is not worth the reduced risk of recurrence, or conflicting beliefs about the harms and benefits of treatment. Additional themes were living with risk of recurrence and information & support.

CONCLUSIONS

Women who believed that the necessity of tamoxifen outweighed its costs were more likely to be adherent, whereas women who thought that the benefits did not outweigh the side effects were more likely to have discontinued. A third more ambivalent group believed strongly in the importance of treatment, but were struggling with side effects and were often non-adherent. Patients sometimes felt unsupported and discussed a need for more comprehensive information. To increase adherence, future research needs to explore ways to increase beliefs around tamoxifen necessity and how to help women cope with side effects. Statement of contribution What is already known on this subject? Non-adherence to tamoxifen is associated with increased risk of recurrence and mortality. Up to 50% of patients are non-adherent to tamoxifen by the fifth year of treatment Few consistent predictors of tamoxifen non-adherence have been identified. What does this study add? Many women report not knowing how to manage their side effects. Non-adherence is related to how women weigh up their side effects against their medication beliefs. Interventions aiming to increase necessity beliefs and improve symptom management may be effective.

Barriers and facilitators of adjuvant hormone therapy adherence and persistence in women with breast cancer: a systematic review

PURPOSE

Nonadherence to hormone therapy in breast cancer survivors is common and associated with increased risk of mortality. Consistent predictors of nonadherence and nonpersistence are yet to be identified, and little research has examined psychosocial factors that may be amenable to change through intervention. This review aimed to identify predictors of nonadherence and nonpersistence to hormone therapy in breast cancer survivors in order to inform development of an intervention to increase adherence rates.

METHODS

Studies published up to April 2016 were identified through MEDLINE, Embase, Web of Science, PsycINFO, CINAHL and gray literature. Studies published in English measuring associations between adherence or persistence and any predictor variables were included. Eligible studies were assessed for methodological quality, data were extracted and a narrative synthesis was conducted.

RESULTS

Sixty-one eligible articles were identified. Most studies focused on clinical and demographic factors with inconsistent results. Some evidence suggested that receiving specialist care and social support were related to increased persistence, younger age and increased number of hospitalizations were associated with nonadherence, and good patient-physician relationship and self-efficacy for taking medication were associated with better adherence. A small amount of evidence suggested that medication beliefs were associated with adherence, but more high-quality research is needed to confirm this.

CONCLUSION

Some psychosocial variables were associated with better adherence and persistence, but the results are currently tentative. Future high-quality research should be carried out to identify psychosocial determinants of nonadherence or nonpersistence that are modifiable through intervention.

Supporting adherence to oral anticancer agents: clinical practice and clues to improve care provided by physicians, nurse practitioners, nurses and pharmacists

Background

Healthcare provider (HCP) activities and attitudes towards patients strongly influence medication adherence. The aim of this study was to assess current clinical practices to support patients in adhering to treatment with oral anticancer agents (OACA) and to explore clues to improve the management of medication adherence.

Methods

A cross-sectional, observational study among HCPs in (haemato-)oncology settings in Belgium and the Netherlands was conducted in 2014 using a composite questionnaire. A total of 47 care activities were listed and categorised into eight domains. HCPs were also asked about their perceptions of adherence management on the items: insight into adherence, patients’ communication, capability to influence, knowledge of consequences and insight into causes. Validated questionnaires were used to assess beliefs about medication (BMQ) and shared decision making (SDM-Q-doc).

Results

In total, 208 HCPs (29% male) participated; 107 from 51 Dutch and 101 from 26 Belgian hospitals. Though a wide range of activities were reported, certain domains concerning medication adherence management received less attention. Activities related to patient knowledge and adverse event management were reported most frequently, whereas activities aimed at patient’s self-efficacy and medication adherence during ongoing use were frequently missed. The care provided differed between professions and by country. Belgian physicians reported more activities than Dutch physicians, whereas Dutch nurses and pharmacists reported more activities than Belgian colleagues. The perceptions of medication adherence management were related to the level of care provided by HCPs. SDM and BMQ outcomes were not related to the care provided.

Conclusions

Enhancing the awareness and perceptions of medication adherence management of HCPs is likely to have a positive effect on care quality. Care can be improved by addressing medication adherence more directly e.g., by questioning patients about (expected) barriers and discussing strategies to overcome them, by asking for missed doses and offering (electronic) reminders to support long-term medication adherence. A multidisciplinary approach is recommended in which the role of the pharmacist could be expanded.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3110-2) contains supplementary material, which is available to authorized users.

Exploring the role of physician communication about adjuvant endocrine therapy among breast cancer patients on active treatment: a qualitative analysis

PURPOSE

To better understand how physicians communicate with breast cancer patients about adjuvant endocrine therapy (AET), we explored, from the breast cancer patient's perspective, dimensions of the patient-provider communication among women who were on active AET treatment.

METHODS

Qualitative methods using semi-structured in-depth interviews were conducted with breast cancer patients (n = 22) who filled a prescription for AET in the previous 12 months. Interview questions aimed to elicit experiences with AET. We reviewed and coded interview transcripts using qualitative principles of inductive reasoning to identify concepts and themes from interview data.

RESULTS

We grouped emergent themes into four major functions of physician-patient communication: (1) information exchange, (2) decision-making to take and continue AET, (3) enabling patient self-management and monitoring potential side effects, and (4) emotional support. Physicians exchanged information with patients in a way that they understood and enhanced patient's health literacy regarding the benefits and knowledge of AET. Physicians empowered patients to make decisions about their care. Patients expressed trust and confidence in their physician which helped them seek care when needed. Patients reported a high degree of self-efficacy to self-manage AET and were continuing treatment despite potential side effects.

CONCLUSIONS

The results from our study suggest that women's interactions and communication with their physician may be an important factor that contributes to the continued use of AET. Physicians who can communicate information about AET treatment benefits, purpose, and expectations in a way that patients can understand is a critical aspect of care that needs to be further studied.

Use of implicit persuasion in decision making about adjuvant cancer treatment: A potential barrier to shared decision making

BACKGROUND

Shared decision making (SDM) is widely advocated, especially for preference-sensitive decisions like those on adjuvant treatment for early-stage cancer. Here, decision making involves a subjective trade-off between benefits and side-effects, and therefore, patients' informed preferences should be taken into account. If clinicians consciously or unconsciously steer patients towards the option they think is in their patients' best interest (i.e. implicit persuasion), they may be unwittingly subverting their own efforts to implement SDM. We assessed the frequency of use of implicit persuasion during consultations and whether the use of implicit persuasion was associated with expected treatment benefit and/or decision making.

METHODS

Observational study design in which consecutive consultations about adjuvant systemic therapy with stage I-II breast cancer patients treated at oncology outpatient clinics of general teaching hospitals and university medical centres were audiotaped, transcribed and coded by two researchers independently.

RESULTS

In total, 105 patients (median age = 59; range: 35-87 years) were included. A median of five (range: 2-10) implicitly persuasive behaviours were employed per consultation. The number of behaviours used did not differ by disease stage (P = 0.07), but did differ by treatment option presented (P = 0.002) and nodal status (P = 0.01). About 50% of patients with stage I or node-negative disease were steered towards undergoing chemotherapy, whereas 96% of patients were steered towards undergoing endocrine therapy, irrespective of expected treatment benefit. Decisions were less often postponed if more implicit persuasion was used (P = 0.03).

INTERPRETATION

Oncologists frequently use implicit persuasion, steering patients towards the treatment option that they think is in their patients' best interest. Expected treatment benefit does not always seem to be the driving force behind implicit persuasion. Awareness of one's use of these steering behaviours during decision making is a first step to help overcome the performance gap between advocating and implementing SDM.

Understanding Statin Non-Adherence: Knowing Which Perceptions and Experiences Matter to Different Patients

Background

Non-adherence to statins is substantial and is associated with numerous perceptions and experiences. However, time limits in clinical practice constrain in depth explorations of these perceptions and experiences.

Objectives

To propose and examine a strategy aimed at an efficient assessment of a wide array of perceptions and experiences regarding the efficacy, side effects, and practical problems of statins. Furthermore, to assess associations between this wide array of experiences and perceptions and non-adherence and to examine whether patients' 'perceived self-efficacy' moderated these associations.

Methods

Patients were recruited through community pharmacies. A wide array of specific patient perceptions and experiences was efficiently assessed using the electronic Tailored Medicine Inventory that allows people to skip irrelevant questions. Adherence was measured through self-report and pharmacy refill data.

Results

Of the two-hundred twenty-nine patients who participated (mean age 63.9, standard deviation 10.2), 40%-70% doubted the necessity of or lacked knowledge about the efficacy of statins, 20%-35% of the patients were worried about joint and muscle side effects or had experienced these, and 23% had encountered practical problems regarding information about statins, intake of tablets, the package, or the blister. Experiencing more practical problems was associated with increased unintentional non-adherence (Odds ratio 1.54, 95%CI:1.13–2.10, P < 0.01), whereas worrying about side effects was associated with increased intentional non-adherence (Odds ratio 1.90, 95%CI:1.17–3.08, P < 0.01). Higher 'perceived self-efficacy' did not moderate these associations.

Conclusions

Insight into patients' specific barriers with regard to appropriate statin use may reveal personal reasons for being non-adherent. The Tailored Medicine Inventory is a promising tool to devise individualized intervention strategies aimed at improving adherence by the clinician-patient alliance.

How can we best respect patient autonomy in breast cancer treatment decisions?

Helping patients to maximize their autonomy in breast cancer decision-making is an important aspect of patient-centered care. Shared decision-making is a strategy that aims to maximize patient autonomy by integrating the values and preferences of the patient with the biomedical expertise of the physician. Application of this approach in breast cancer decision-making has not been uniform across cancer-specific interventions (e.g., surgery, chemotherapy), and in some circumstances may present challenges to evidence-based care delivery. Increasingly precise estimates of individual patients' risk of recurrence and commensurate predicted benefit from certain therapies hold significant promise in helping patients exercise autonomous decision-making for their breast cancer care, yet will also likely complicate decision-making for certain subgroups of patients.