Adherence evaluation of endocrine treatment in breast cancer: methodological aspects

[Adherence to endocrine therapy: A major issue in breast cancer management]

Endocrine therapy plays a crucial role in the treatment of women with hormone receptor-positive breast cancer. However, non-adherence remains a frequent issue known to negatively impact survival. Based on a comprehensive literature review, this article explores the terminologies employed to describe adherence and methods used for its assessment, the adherence data reported with adjuvant endocrine therapy with targeted therapies, the determinants of adherence or non-adherence, and finally, tested solutions to address it. The results show that a better understanding of the causes of non-adherence would help to better identify patients at risk, and to develop personalized intervention programs capable of improving adherence to adjuvant endocrine therapy. In light of the literature, interventions are likely to require a multimodal approach and integration into our future healthcare pathways.

The Simplified Medication Adherence Questionnaire: validation of a Brazilian-Portuguese version in hypertensive adults

Background

Self-reported adherence scales are widely used in research and practice because they are low in cost and easy to apply. A free version in Brazilian-Portuguese of the Simplified Medication Adherence Questionnaire (SMAQ) can be a useful alternative for determining the adherent behavior of hypertensive patients.

Purpose

To translate and evaluate the psychometric properties of the Brazilian-Portuguese version of the SMAQ therapeutic adherence scale for patients with arterial hypertension.

Patients and methods

A multicenter, cross-sectional study was conducted in five outpatient units in Maceió-AL and Aracaju-SE between January and July 2019. A total of 117 patients aged over 18 years using antihypertensive drugs were recruited. The cross-cultural adaptation followed international methodological recommendations. Internal consistency (Cronbach's alpha) was tested as a reliability parameter. Criterion and construct validity were verified by concurrent validation, exploratory factor analysis (EFA), and validation by known groups.

Results

The participants had a mean age of 56.6 years (SD = 10.7 years); most were female (72.6%). The mean number of antihypertensives prescribed per patient was 1.87 (SD = 0.87). There were 79.5% (n = 86) of patients considered non-adherent. Internal consistency was satisfactory (Cronbach's alpha = 0.63). A satisfactory correlation coefficient was verified with the Morisky-Green-Levine test as an external criterion (r = 0.56, p < 0.001). The scale's sensitivity measured through known group validity was 75.3%, specificity 29.5%, positive predictive value 63.9%, and negative predictive value 41.9%. We identified two factors of the instrument's construct from EFA: specific medication-taking behaviors and barriers to adherence. The initial KMO measure of sampling adequacy was 0.691, and Bartlett's test of sphericity was significant (χ2 = 118.342, p < 0.001).

Conclusion

The Brazilian-Portuguese version of the SMAQ scale proved valid and reliable for determining adherence to the pharmacotherapy in hypertensive patients. It showed more ability to detect non-adherent patients but with low specificity, possibly influenced by high social desirability.

Beliefs about medicines' association with endocrine therapy adherence in early breast cancer survivors in Croatia

This observational, cross-sectional study conducted at the University Hospital Centre Zagreb (UHC Zagreb) aimed to explore patients' beliefs about adjuvant endocrine therapy (AET) as well as their association with non-adherence and sociodemographic and clinical factors. Out of 420 early breast cancer (BC) patients included in the study, 79.5 % perceived AET necessary and important for their health, as measured by the Belief About Medicines Questionnaire (BMQ), with the mean necessity score (20.4 ± 3.68) significantly higher than the mean concerns score (13 ± 4.81) (p < 0.001). Based on the Medication Adherence Report Scale (MARS-5), 44.4 % (n = 182) of the participants were non-adherers, out of which 63.2 % (n = 115) were unintentional and 36.8 % (n = 67) intentional non-adherers. Significantly higher concern beliefs were found among patients that were younger (p < 0.001), employed (p < 0.001), intentionally non-adherent to AET (p = 0.006), had a lower body-mass index (p = 0.005) and a higher level of education (p < 0.001), were premenopausal at the time of diagnosis (p < 0.001), taking tamoxifen treatment (p = 0.05) and receiving ovarian suppression (p < 0.001). Younger patients should be recognized as being at risk of non-adherence as they hold greater concern beliefs about medicines.

Importance of endocrine treatment adherence and persistence in breast cancer survivorship: a systematic review

PURPOSE

Adjuvant endocrine treatment is essential for treating luminal subtypes of breast cancer, which constitute 75% of all breast malignancies. However, the detrimental side effects of treatment make it difficult for many patients to complete the guideline-required treatment. Such non-adherence may jeopardize the lifesaving ability of anti-estrogen therapy. In this systematic review, we aimed to assess the consequences of non-adherence and non-persistence from available studies meeting strict statistical and clinical criteria.

METHODS

A systematic literature search was performed using several databases, yielding identification of 2,026 studies. After strict selection, 14 studies were eligible for systematic review. The review included studies that examined endocrine treatment non-adherence (patients not taking treatment as prescribed) or non-persistence (patients stopping treatment prematurely), in terms of the effects on event-free survival or overall survival among women with non-metastatic breast cancer.

RESULTS

We identified 10 studies measuring the effects of endocrine treatment non-adherence and non-persistence on event-free survival. Of these studies, seven showed significantly poorer survival for the non-adherent or non-persistent patient groups, with hazard ratios (HRs) ranging from 1.39 (95% CI, 1.07 to 1.53) to 2.44 (95% CI, 1.89 to 3.14). We identified nine studies measuring the effects of endocrine treatment non-adherence and non-persistence on overall survival. Of these studies, seven demonstrated significantly reduced overall survival in the groups with non-adherence and non-persistence, with HRs ranging from 1.26 (95% CI, 1.11 to 1.43) to 2.18 (95% CI, 1.99 to 2.39).

CONCLUSION

The present systematic review demonstrates that non-adherence and non-persistence to endocrine treatment negatively affect event-free and overall survival. Improved follow-up, with focus on adherence and persistence, is vital for improving health outcomes among patients with non-metastatic breast cancer.

Comparison of Approaches for Measuring Adherence and Persistence to Oral Oncologic Therapies in Patients Diagnosed with Metastatic Renal Cell Carcinoma

BACKGROUND

Adherence and persistence studies face several methodologic difficulties, including short-term mortality. We compared approaches to quantify adherence and persistence to first line (1L) oral targeted therapy (TT) in patients diagnosed with metastatic renal cell carcinoma (mRCC).

METHODS

Patients with mRCC ages 66 years or more who initiated TTs within 4 months of diagnosis were identified in the Surveillance, Epidemiology, and End Results Medicare-linked database (2007-2015). Adherence [proportion of days covered (PDC) >80%] was calculated using (i) PDC with a fixed 6-month denominator including then excluding patients who died within the 6 months and (ii) PDC with a denominator measuring time on treatment. Risk of nonpersistence was obtained by censoring death or treating death as a competing risk using cumulative incidence functions.

RESULTS

Among 485 patients with mRCC initiating a 1L oral TT (sunitinib, 64%; pazopanib, 25%; other, 11%), 40% died within 6 months. Adherence was higher after restricting to patients who survived (60%) compared with including those patients and assigning zero days covered after death (47%). Risk of nonpersistence was higher when censoring patients at death, 0.91 [95% confidence interval (CI), 0.88-0.94], compared with treating death as a competing risk, 0.75 (95% CI, 0.71-0.79).

CONCLUSIONS

Different approaches to handling death resulted in different adherence and persistence estimates in the metastatic setting. Future studies should explicitly report the proportion of patient deaths over time and explore appropriate methods to account for death as competing risk.

IMPACT

Use of several approaches can provide a more comprehensive picture of medication-taking behavior in the metastatic setting where death is a major competing risk.

OUP accepted manuscript

Introduction

Many women in rural Ethiopia do not receive adjuvant therapy following breast cancer surgery despite the majority being diagnosed with estrogen-receptor-positive breast cancer and tamoxifen being available in the country. We aimed to compare a breast nurse intervention to improve adherence to tamoxifen therapy for breast cancer patients.

Methods and Materials

The 8 hospitals were randomized to intervention and control sites. Between February 2018 and December 2019, patients with breast cancer were recruited after their initial surgery. The primary outcome of the study was adherence to tamoxifen therapy by evaluating 12-month medication-refill data with medication possession ratio (MPR) and using a simplified medication adherence scale (SMAQ) in a subjective assessment.

Results

A total of 162 patients were recruited (87 intervention and 75 control). Trained nurses delivered education and provided literacy material, gave additional empathetic counselling, phone call reminders, and monitoring of medication refill at the intervention hospitals. Adherence according to MPR at 12 months was high in both the intervention (90%) and control sites (79.3%) (P = .302). The SMAQ revealed that adherence at intervention sites was 70% compared with 44.8% in the control sites (P = .036) at 12 months. Persistence to therapy was found to be 91.2% in the intervention and 77.8% in the control sites during the one-year period (P = .010).

Conclusion

Breast nurses can improve cost-effective endocrine therapy adherence at peripheral hospitals in low-resource settings. We recommend such task sharing to overcome the shortage of oncologists and distances to central cancer centers.

Machine Learning to Predict Tamoxifen Nonadherence Among US Commercially Insured Patients With Metastatic Breast Cancer

PURPOSE

Adherence to tamoxifen citrate among women diagnosed with metastatic breast cancer can improve survival and minimize recurrence. This study aimed to use real-world data and machine learning (ML) methods to classify tamoxifen nonadherence.

METHODS

A cohort of women diagnosed with metastatic breast cancer from 2012 to 2017 were identified from IBM MarketScan Commercial Claims and Encounters and Medicare claims databases. Patients with < 80% proportion of days coverage in the year following treatment initiation were classified as nonadherent. Training and internal validation cohorts were randomly generated (4:1 ratio). Clinical procedures, comorbidity, treatment, and health care encounter features in the year before tamoxifen initiation were used to train logistic regression, boosted logistic regression, random forest, and feedforward neural network models and were internally validated on the basis of area under receiver operating characteristic curve. The most predictive ML approach was evaluated to assess feature importance.

RESULTS

A total of 3,022 patients were included with 40% classified as nonadherent. All models had moderate predictive accuracy. Logistic regression (area under receiver operating characteristic 0.64) was interpreted with 94% sensitivity (95% CI, 89 to 92) and 0.31 specificity (95% CI, 29 to 33). The model accurately classified adherence (negative predictive value 89%) but was nondiscriminate for nonadherence (positive predictive value 48%). Variable importance identified top predictive factors, including age ≥ 55 years and pretreatment procedures (lymphatic nuclear medicine, radiation oncology, and arterial surgery).

CONCLUSION

ML using baseline administrative data predicts tamoxifen nonadherence. Screening at treatment initiation may support personalized care, improve health outcomes, and minimize cost. Baseline claims may not be sufficient to discriminate adherence. Further validation with enriched longitudinal data may improve model performance.

Serum Detection of Nonadherence to Adjuvant Tamoxifen and Breast Cancer Recurrence Risk

PURPOSE

Nonadherence to long-term treatments is often under-recognized by physicians and there is no gold standard for its assessment. In breast cancer, nonadherence to tamoxifen therapy after surgery constitutes a major obstacle to optimal outcomes. We sought to evaluate the rate of biochemical nonadherence to adjuvant tamoxifen using serum assessment and to examine its effects on short-term, distant disease-free survival (DDFS).

PATIENTS AND METHODS

We studied 1,177 premenopausal women enrolled in a large prospective study (CANTO/NCT01993498). Definition of biochemical nonadherence was based on a tamoxifen serum level < 60 ng/mL, assessed 1 year after prescription. Self-reported nonadherence to tamoxifen therapy was collected at the same time through semistructured interviews. Survival analyses were conducted using an inverse probability weighted Cox proportional hazards model, using a propensity score based on age, staging, surgery, chemotherapy, and center size.

RESULTS

Serum assessment of tamoxifen identified 16.0% of patients (n = 188) below the set adherence threshold. Patient-reported rate of nonadherence was lower (12.3%). Of 188 patients who did not adhere to the tamoxifen prescription, 55% self-reported adherence to tamoxifen. After a median follow-up of 24.2 months since tamoxifen serum assessment, patients who were biochemically nonadherent had significantly shorter DDFS (for distant recurrence or death, adjusted hazard ratio, 2.31; 95% CI, 1.05 to 5.06; P = .036), with 89.5% of patients alive without distant recurrence at 3 years in the nonadherent cohort versus 95.4% in the adherent cohort.

CONCLUSION

Therapeutic drug monitoring may be a useful method to promptly identify patients who do not take adjuvant tamoxifen as prescribed and are at risk for poorer outcomes. Targeted interventions facilitating patient adherence are needed and have the potential to improve short-term breast cancer outcomes.

Hyphenated mass spectrometry techniques for assessing medication adherence: advantages, challenges, clinical applications and future perspectives

Nonadherence to prescribed pharmacotherapy is an understated public health problem globally and is costing many patients their chance to return to good health and healthcare systems billions. Clinicians need an accurate assessment of adherence to medications to aid the clinical decision-making process in the event of poor patient progress and to maximise the patient health outcomes from the drug therapies prescribed. An overview of indirect and direct methods used to measure medication adherence is presented, highlighting the potential for accurate measuring of drugs in biological samples using hyphenated mass spectrometry (MS) techniques to provide healthcare professionals with a reliable evidence base for clinical decision making. In this review we summarise published applications of hyphenated MS techniques for a diverse range of clinical areas demonstrating the rise in the use of such direct methods for assessing medication adherence. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using plasma, serum and urine samples are the most popular, in recent years increased attention has been given to liquid chromatography high-resolution mass spectrometry (LC-HRMS) methods and alternative biosample matrices including hair, saliva and blood microsamples. The advantages and challenges of using hyphenated MS techniques to address this healthcare problem are also discussed alongside future perspectives.

Nonadherent behaviors among young women on adjuvant endocrine therapy for breast cancer

BACKGROUND

Young age is a known factor associated with suboptimal adherence to endocrine therapy (ET) for adjuvant breast cancer (BC) treatment. This study was aimed at assessing nonadherent behaviors and associated factors among young women with early-stage hormone receptor-positive BC.

METHODS

As part of a multicenter, prospective cohort of women with a diagnosis of BC at or under the age of 40 years, participants were surveyed 30 months after their diagnosis about adherent behaviors. Among those who reported taking ET, adherence was measured with a 3-item Likert-type scale: Do you ever forget to take your ET? If you feel worse when you take your ET, do you stop taking it? Did you take your ET exactly as directed by your doctor over the last 3 months? Women reporting at least 1 nonadherent behavior were classified as nonadherers. Variables with a P value <.20 were included in a multivariable logistic model.

RESULTS

Among 384 women, 194 (51%) were classified as nonadherers. Univariate factors that retained significance in the multivariable model included educational level (odds ratio [OR], 0.50 for high vs low; P = .04), level of social support according to the Medical Outcome Study Social Support Survey (OR, 0.98 per 1 point; P = .01), and confidence with the decision regarding ET measured on a 0 to 10 numerical scale (OR, 0.63 for high vs low; P = .04).

CONCLUSIONS

Findings from this study could help to identify young patients at higher risk for nonadherence. Interventions adapted to the level of education and aimed at reinforcing support and patients' confidence in their decision to take ET could improve adherence and associated outcomes in this population.

Distinct Profiles on Subjective and Objective Adherence Measures in Patients Prescribed Antidepressants

Objective

A recurrent observation is that associations between self-reported and objective medication adherence measures are often weak to moderate. Our aim was therefore to identify patients with different profiles on self-reported and objective adherence measures.

Study Design and Setting

This was an observational study of 221 community pharmacy patients who were dispensed antidepressants. Adherence profiles were estimated with Latent Profile Analysis (LPA) using data on self-reported adherence (Medication Adherence Rating Scale) complemented with data on medication beliefs (perceived necessity and concerns measured with the Beliefs about Medicines Questionnaire) and data from objective adherence measures (electronic monitoring of medication taking and the Medication Possession Ratio calculated from pharmacy dispensing data).

Results

‘Goodness-of-fit’ statistics indicated the presence of three classes: “concordantly high adherent” (83%, high adherence on all measures), “concordantly suboptimal adherent” (11%, low adherence on all measures), and “discordant” (6%, high self-reported adherence but lower adherence on objective measures).

Conclusion

Most patients had concordant outcomes on self-reported and objective measures of adherence. A small discordant class had high self-reported but low objective adherence. LPA will enable sensitivity analyses in future studies, for example excluding patients from the discordant class.

Testing a behavioral intervention to improve adherence to adjuvant endocrine therapy (AET)

Adjuvant endocrine therapy (AET) is used to prevent recurrence and reduce mortality for women with hormone receptor positive breast cancer. Poor adherence to AET is a significant problem and contributes to increased medical costs and mortality. A variety of problematic symptoms associated with AET are related to non-adherence and early discontinuation of treatment. The goal of this study is to test a novel, telephone-based coping skills training that teaches patients adherence skills and techniques for coping with problematic symptoms (CST-AET). Adherence to AET will be assessed in real-time for 18 months using wireless smart pill bottles. Symptom interference (i.e., pain, vasomotor symptoms, sleep problems, vaginal dryness) and cost-effectiveness of the intervention protocol will be examined as secondary outcomes. Participants (N = 400) will be recruited from a tertiary care medical center or community clinics in medically underserved or rural areas. Participants will be randomized to receive CST-AET or a general health education intervention (comparison condition). CST-AET includes ten nurse-delivered calls delivered over 6 months. CST-AET provides systematic training in coping skills for managing symptoms that interfere with adherence. Interactive voice messaging provides reinforcement for skills use and adherence that is tailored based on real-time adherence data from the wireless smart pill bottles. Given the high rates of non-adherence and recent recommendations that women remain on AET for 10 years, we describe a timely trial. If effective, the CST-AET protocol may not only reduce the burden of AET use but also lead to cost-effective changes in clinical care and improve breast cancer outcomes. Trials registration: ClinicalTrials.gov, NCT02707471, registered 3/3/2016.

Oral Endocrine Therapy Nonadherence, Adverse Effects, Decisional Support, and Decisional Needs in Women With Breast Cancer

BACKGROUND

Oral endocrine therapy (OET) such as tamoxifen or aromatase inhibitors reduces recurrence and mortality for the 75% of breast cancer survivors (BCSs) with a diagnosis of estrogen receptor-positive breast cancer. Because many BCSs decide not take OET as recommended because of adverse effects, understanding BCSs' decisional supports and needs is foundational to supporting quality OET decision making about whether to adhere to OET.

OBJECTIVE

The aim of this study was to examine literature pertaining to OET nonadherence and adverse effects using the Ottawa Decision Support Framework categories of decisional supports and decisional needs because these factors potentially influence OET use.

METHODS

A systematic literature search was performed in PubMed and CINAHL using combined search terms "aromatase inhibitors and adherence" and "tamoxifen and adherence." Studies that did not meet criteria were excluded. Relevant data from 25 publications were extracted into tables and reviewed by 2 authors.

RESULTS

Findings identified the impact of adverse effects on OET nonadherence, an absence of decisional supports provided to or available for BCSs who are experiencing OET adverse effects, and the likelihood of unmet decisional needs related to OET.

CONCLUSIONS

Adverse effects contribute to BCSs decisions to stop OET, yet there has been little investigation of the process through which that occurs. This review serves as a call to action for providers to provide support to BCSs experiencing OET adverse effects and facing decisions related to nonadherence.

IMPLICATIONS FOR PRACTICE

Findings suggest BCSs prescribed OET have unmet decisional needs, and more decisional supports are needed for BCSs experiencing OET adverse effects.

Talking About My Care: Detecting Mentions of Hormonal Therapy Adherence Behavior in an Online Breast Cancer Community

Hormonal therapy adherence is challenging for many patients with hormone-receptor-positive breast cancer. Gaining intuition into their adherence behavior would assist in improving outcomes by pinpointing, and eventually addressing, why patients fail to adhere. While traditional adherence studies rely on survey-based methods or electronic medical records, online health communities provide a supplemental data source to learn about such behavior and often on a much larger scale. In this paper, we focus on an online breast cancer discussion forum and propose a framework to automatically extract hormonal therapy adherence behavior (HTAB) mentions. The framework compares medical term usage when describing when a patient is taking hormonal therapy medication and interrupting their treatment (e.g., stop/pause taking medication). We show that by using shallow neural networks, in the form of wordlvec, the learned features can be applied to build efficient HTAB mention classifiers. Through medical term comparison, we find that patients who exhibit an interruption behavior are more likely to mention depression and their care providers, while patients with continuation behavior are more likely to mention common side effects (e.g., hot flashes, nausea and osteoporosis), vitamins and exercise.

Interventions to improve endocrine therapy adherence in breast cancer survivors: what is the evidence?

PURPOSE

Endocrine therapy reduces the risk of breast cancer recurrences and mortality in hormone receptor-positive (HR+) breast cancer survivors. However, non-adherence to treatment remains a significant problem. The aim of this study was to review current literature and ongoing trials to identify interventions employed to improve adherence to adjuvant endocrine therapy (AET) in breast cancer survivors.

METHODS

We searched PubMed and the National Library of Medicine registry of clinical trials using the terms "breast cancer" and "adherence" or "compliance" and "intervention" and "medication" or "endocrine therapy" or "hormone therapy" to identify published studies as well as ongoing clinical trials.

RESULTS

Three hundred and sixty-three studies were identified; five studies met the inclusion criteria. Most studies enrolled postmenopausal women diagnosed with early stage HR+ breast cancer. Providing educational materials was the most common intervention implemented to improve adherence to one or more aromatase inhibitors. None of the studies found a significant improvement in adherence with the intervention evaluated. Twelve clinical trials investigating various interventions, mostly based on technology, to improve AET adherence were also identified.

CONCLUSIONS

Improving adherence to AET in HR+ breast cancer survivors is an urgent medical need. While newer clinical trials are overcoming some of the limitations seen with published studies, tailored interventions led by clinicians need further investigation.

IMPLICATIONS FOR CANCER SURVIVORS

Our study highlights the unmet clinical need to develop and test feasible interventions to improve AET adherence in HR+ breast cancer survivors to extend their long-term survival.

Early participant-reported symptoms as predictors of adherence to anastrozole in the International Breast Cancer Intervention Studies II

Background

Anastrozole reduces breast cancer risk in women at high risk, but implementing preventive therapy in clinical practice is difficult. Here, we evaluate adherence to anastrozole in the International Breast Cancer Intervention Study (IBIS)-II prevention and ductal carcinoma in situ (DCIS) trials, and its association with early symptoms.

Patients and methods

In the prevention trial, 3864 postmenopausal women were randomized to placebo versus anastrozole. A total of 2980 postmenopausal women with DCIS were randomized to tamoxifen versus anastrozole. Adherence to trial medication was calculated using the Kaplan-Meier method and all P-values were two-sided.

Results

In the prevention trial, adherence was 65.8% [anastrozole (65.7%) versus placebo (65.9%); HR = 0.97 (0.87-1.09), P = 0.6]. Adherence was lower for those reporting arthralgia in the placebo group (P = 0.02) or gynecological symptoms in the anastrozole group (P = 0.003), compared with those not reporting these symptoms at 6 months. In the DCIS study, adherence was 66.7% [anastrozole (67.5%) versus tamoxifen (65.8%); HR = 1.06 (0.94-1.20), P = 0.4]. Hot flashes were associated with greater adherence in the anastrozole arm (P = 0.02). In both studies, symptoms were mostly mild or moderately severe, and adherence decreased with increasing severity for most symptoms. Drop-outs were highest in the first 1.5 years of therapy in both trials.

Conclusions

In the IBIS-II prevention and DCIS trials, over two-thirds of women were adherent to therapy, with no differences by treatment groups. Participants who reported specific symptoms in the IBIS-II prevention trial had a small but significant effect on adherence, which strengthened as severity increased. Strategies to promote adherence should target the first year of preventive therapy.

Adherence to Adjuvant Endocrine Therapy in Women With Breast Cancer: A Prospective Observational Study in Japanese Women

INTRODUCTION

Nonadherence to adjuvant endocrine therapy has been poorly studied in Asian patients with breast cancer. We therefore assessed adherence to endocrine therapy among women with breast cancer in Japan.

PATIENTS AND METHODS

We conducted a prospective observational study among Japanese women with hormone receptor-positive breast cancer. Patients brought their pill packets to visits for 1 year and answered a questionnaire. We also examined prescription records during the study period. Adherence to endocrine therapy was defined as patients who had taken > 80% of the pills according to the packets during the study. Clinicopathologic features and questionnaires were compared between adherent and nonadherent patients.

RESULTS

A total of 234 patients completed the trial, of whom 85% demonstrated adherence based on pill packets, and 98% demonstrated adherence based on prescription records. Mastectomy, higher stage, nodal metastasis and adjuvant chemotherapy were correlated with adherence based on pill packets. Adjuvant chemotherapy was an independent factor associated with adherence. According to the questionnaire, adherent patients were more likely to consult a nurse when they had trouble with their medication. These patients also emphasized the efficacy rather than the side effects of the medication. Nonadherent patients were aware that they were being nonadherent.

CONCLUSION

The results of this study revealed that 85% of patients were adherent to endocrine therapy, but physicians were unaware of the nonadherent patients. Raised awareness of nonadherence and information sharing between patients and medical teams might increase adherence to endocrine therapy.

Fatores associados à adesão e à persistência na hormonioterapia em mulheres com câncer de mama

RESUMO: Introdução: A hormonioterapia no câncer de mama é fundamental para a transição do tratamento ativo aos cuidados de sobrevivência, pois melhora significativamente os resultados de sobrevida em longo prazo, além de propiciar melhor qualidade de vida e reduzir os custos de hospitalização. Porém, para atingir resultados desejáveis, são importantes a adesão e a persistência no tratamento recomendado. Metodologia: Estudo de coorte retrospectivo com 182 mulheres em tratamento hormonal identificadas em unidade oncológica de alta complexidade da Região Sudeste do Brasil e acompanhadas até 2014. Foram realizadas análise bivariada, para investigar os fatores associados à adesão, e regressão multivariada de Cox, para identificar variáveis associadas à descontinuidade do tratamento ao longo do tempo. Resultados: A adesão geral foi de 85,2% e a persistência, de 45,4% após 5 anos. Não foi encontrada associação entre as variáveis independentes estudadas e a adesão. Mulheres com estadiamento avançado (hazard ratio - HR = 2,24; intervalo de confiança de 95% - IC95% 1,45 - 3,45), que não realizaram cirurgia (HR = 3,46; IC95% 2,00 - 5,97) e com 3 ou mais internações hospitalares (HR = 6,06; IC95% 2,53 - 14,54) exibiram maior risco de descontinuidade. Discussão: As variáveis associadas à persistência refletem a relação entre a maior gravidade da doença e a interrupção do tratamento hormonal adjuvante. Conclusão: Apesar da alta adesão, observa-se aumento progressivo do número de pacientes que não persistem no tratamento, devido a características relacionadas à gravidade da doença, contribuindo para uma resposta terapêutica inadequada.

Adherence to Adjuvant Endocrine Therapy in Christchurch Women with Early Breast Cancer

AIMS

To assess adherence to adjuvant endocrine therapy by a real-world cohort of women in Christchurch and to determine any associated factors.

MATERIALS AND METHODS

Records were retrieved of all women newly diagnosed with early breast cancer and registered on the Christchurch Breast Cancer Patient Register over 4 years from June 2009. Demographic and pathological factors, dates of starting and stopping endocrine therapies and reported side-effects were collected. The proportion remaining on endocrine therapy was analysed by Kaplan-Meier curve; Cox regression analysis was used to identify independent factors influencing adherence.

RESULTS

Of 1213 women, 1018 (83.9%) had oestrogen receptor-positive tumours, of whom 674 (66.2%) started adjuvant endocrine therapy, including 62 (9.2%) neoadjuvantly. Uptake was 52.4% of those with T1 tumours, 89% with T2 tumours, 93% with T3/T4 tumours, 92.7% with node-positive tumours and 49.7% with node-negative tumours. The initial endocrine therapy was an aromatase inhibitor in 254 (38%) and tamoxifen for 412 (61%). At 1 year, 90% remained adherent, at 2 years 84%, at 3 years 81%, at 4 years 76%, at 4.5 years 71% and at 5 years 50%, with a median duration of 60 months (56-64 months, 95% confidence interval) and a median follow-up of 33 months. Overall, 135 (20%) women stopped treatment for adverse events or poor tolerability. A longer persistence with endocrine therapy was associated with node-positive tumours (hazard ratio 1.38, P = 0.003), but not first hormone used; aromatase inhibitor compared with tamoxifen, P = 0.76.

CONCLUSION

Adjuvant endocrine therapy use fell to 50% by 5 years, limiting possible survival benefits, providing support for efforts to increase compliance.

A Modified Version of the Greek Simplified Medication Adherence Questionnaire for Hemodialysis Patients

Non-adherence to the therapeutic regimen is an increasingly growing problem especially among patients undergoing hemodialysis. The aim of this study was to modify the Greek version of Simplified Medication Adherence Questionnaire (GR-SMAQ) for patients undergoing hemodialysis (GR-SMAQ-HD) and explore its validity and reliability. Between June 2016 and November 2016 a group of patients undergoing hemodialysis (N=107) completed the Greek version of SMAQ. The study was carried out in three Dialysis Units of Hospitals of Athens and Peloponnese region, Greece. The form of GR-SMAQ was modified specifically for renal patients while four additional items were added so as the tool study all aspects of adherence to hemodialysis regimen. Construct validity was checked through exploratory factor analysis with principal Component Analysis with the Equamax method. Test-retest reliability and internal consistency were tested. Statistical analysis was performed using the IBM SPSS Statistics version 21. The significance level was set up at 5%. The Greek version of SMAQ for patients undergoing hemodialysis includes eight questions. Three factors emerged from factor analysis. Cronbach’s a coefficient was 0.742 for the whole scale and for each subscale was for Medication Adherence 0.75, for Attendance at hemodialysis session 0.856 and for Diet/Fluid restriction was 0.717. The total mean score was 6.29 (±1.82). GR-SMAQ-HD is a reliable and valuable tool that can be used by hemodialysis nurses and students of nursing for detection of adherence levels in clinical practice.

Can we use gonadotropin plasma concentration as surrogate marker for BMI-related incomplete estrogen suppression in breast cancer patients receiving anastrozole?

BACKGROUND

BMI has been suggested to impact on estrogenic activity in patients receiving anastrozole resulting in a reduced treatment efficacy in obese women. Current evidence in this regard is controversially discussed. Since estradiol is inversely correlated with gonadotropins it can be assumed that an impact of BMI is also reflected by gonadotropin plasma concentrations. We aim at investigating the impact of BMI on the hormonal state of breast cancer (BC) patients receiving anastrozole indicated by LH, FSH and SHBG as well as estradiol.

METHODS

We determined gonadotropin-, estradiol- and anastrozole- serum concentrations from postmenopausal, early stage breast cancer patients receiving upfront anastrozole within routine after care. Gonadotropin plasma concentrations were derived from the routine laboratory examination report. A liquid chromatography tandem mass spectrometry method was used for the measurement of anastrozole serum concentrations. BMI was assessed within the routine after-care check-up.

RESULTS

The overall sample comprised 135 BC patients with a mean age of 65.3 years. BMI was significantly correlated with LH, FSH and SHBG. This association was neither influenced by age nor by anastrozole serum concentrations according to the regression model. Despite aromatase inhibition 12% of patients had detectable estrogen levels in routine quantification.

CONCLUSION

Obese women have an altered hormonal situation compared to normally weight women under the same dose of anastrozole. Our study findings are a further indicator for the relevance of BMI in regard of anastrozole metabolism and possible estrogenic activity indicated by gonadotropin plasma level.

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.

A Systematic Review of Adherence to Oral Antineoplastic Therapies

BACKGROUND

Oral antineoplastic therapies not only improve survival but also reduce the burden of care for patients. Yet patients and clinicians face new challenges in managing adherence to these oral therapies. We conducted a systematic literature review to assess rates and correlates of adherence to oral antineoplastic therapies and interventions aimed at improving adherence.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a comprehensive literature search of the Ovid MEDLINE database from January 1, 2003 to June 30, 2015, using relevant terminology for oral antineoplastic agents. We included observational, database, and intervention studies. At least two researchers evaluated each paper to ensure accuracy of results and determine risk of bias.

RESULTS

We identified 927 records from the search and screened 214 abstracts. After conducting a full-text review of 167 papers, we included in the final sample 51 papers on rates/correlates of adherence to oral antineoplastic therapy and 12 papers on intervention studies to improve adherence. Rates of adherence varied widely, from 46% to 100%, depending on patient sample, medication type, follow-up period, assessment measure, and calculation of adherence. Of the intervention studies, only 1 of the randomized trials and 2 of the cohort studies showed benefit regarding adherence, with the majority suffering high risk of bias.

CONCLUSIONS

Although no reliable estimate of adherence to oral antineoplastic therapies can be gleaned from the literature, a substantial proportion of patients struggle to adhere to these medications as prescribed. The few intervention studies for adherence have notable methodological concerns, thereby limiting the evidence to guide practice in promoting medication adherence among patients with cancer.

Effects of a nurse-led medication self-management programme in cancer patients: protocol for a mixed-method randomised controlled trial

BACKGROUND

With the widespread use of orally administered anticancer agents, self-management by cancer patients is inevitable, and adherence to medication is becoming the centre of interest in oncology.

METHODS/DESIGN

This mixed-method study is a two-phased approach with a combined quantitative and qualitative design. In the first phase, we will conduct a prospective randomised controlled study to assess the effects of a nurse-led medication self-management programme for patients receiving oral anticancer treatment. Patients with metastatic breast cancer, who have been newly prescribed an oral chemotherapy or a targeted therapy agent will be enrolled in the study. The participants will be randomly assigned to either the medication self-management support programme group (intervention group) or the conventional care group (control group). This will be an open-label study; therefore, neither the patients nor the nurses will be blinded. Nurses will provide patients in the intervention group with information by using the teach-back method, help patients set a goal based on their preferences, and solve problems through follow-up counselling. The primary outcome measure is adherence to medication, to be measured on the basis of the medication possession ratio (MPR), which is the ratio of the number of days of medication supply to the total days at a specified time interval. We hypothesize that the intervention group will have an MPR of ≥90 % that is significantly higher than that of the control group. Secondary outcome measures include self-efficacy, quality of life, psychological distress, severity and interference of symptoms, patient satisfaction, emergency department visits, and hospital admissions. In the second phase, we will conduct focus-group interviews with intervention nurses, and perform a content analysis to understand their role and challenges these nurses will face in the programme while improving patients' medication adherence.

DISCUSSION

The present study will be the first Japanese study to evaluate the effects of medication self-management support provided by nurses to patients with metastatic breast cancer who are receiving oral anticancer treatment. The study is characterised by a unique patient-centred approach aiming to help patients manage their medication based on their needs and preferences, with both quantitative and qualitative evaluations. The findings will contribute to the facilitation of medication management in cancer patients.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR), Japan, UMIN000016597. (27 February 2015).

Adherence to endocrine therapy in breast cancer adjuvant and prevention settings

Adherence to oral endocrine therapy in adjuvant breast cancer settings is a substantial clinical problem. To provide current perspective on adherence to oral endocrine therapies, a comprehensive literature review was conducted. In adjuvant trials, endocrine therapy adherence is relatively high with greater adherence for aromatase inhibitors compared with tamoxifen. In contrast, adherence to adjuvant therapy in clinical practice is relatively poor, with only about 50% of women successfully completing 5-year therapy. Importantly, good adherence (>80% use) has been associated with lower recurrence risk. Endocrine therapy adherence in primary breast cancer prevention trials parallels that seen in adjuvant trials. Factors associated with nonadherence include low recurrence risk perception, side effects, age extremes, medication cost, suboptimal patient-physician communication, and lack of social support. Few prospective studies have evaluated interventions designed to improve adherence. Interventions currently proposed reflect inferences from clinical trial procedures in which clinical contacts are commonly greater than in usual practice settings. In conclusion, for optimal breast cancer outcome, adherence to endocrine therapy must improve. Although general recommendations likely to improve adherence can be made based on clinical trial results and preliminary prospective trial findings, research specifically targeting this issue is needed to establish effective intervention strategies.

Adjuvant endocrine therapy initiation and persistence in a diverse sample of patients with breast cancer

Adjuvant endocrine therapy for breast cancer reduces recurrence and improves survival rates. Many patients never start treatment or discontinue prematurely. A better understanding of factors associated with endocrine therapy initiation and persistence could inform practitioners how to support patients. We analyzed data from a longitudinal study of 2,268 women diagnosed with breast cancer and reported to the Metropolitan Detroit and Los Angeles SEER cancer registries in 2005-2007. Patients were surveyed approximately both 9 months and 4 years after diagnosis. At the 4-year mark, patients were asked if they had initiated endocrine therapy, terminated therapy, or were currently taking therapy (defined as persistence). Multivariable logistic regression models examined factors associated with initiation and persistence. Of the 743 patients eligible for endocrine therapy, 80 (10.8 %) never initiated therapy, 112 (15.1 %) started therapy but discontinued prematurely, and 551 (74.2 %) continued use at the second time point. Compared with whites, Latinas (OR 2.80, 95 % CI 1.08-7.23) and black women (OR 3.63, 95 % CI 1.22-10.78) were more likely to initiate therapy. Other factors associated with initiation included worry about recurrence (OR 3.54, 95 % CI 1.31-9.56) and inadequate information about side effects (OR 0.24, 95 % CI 0.10-0.55). Factors associated with persistence included two or more medications taken weekly (OR 4.19, 95 % CI 2.28-7.68) and increased age (OR 0.98, 95 % CI 0.95-0.99). Enhanced patient education about potential side effects and the effectiveness of adjuvant endocrine therapy in improving outcomes may improve initiation and persistence rates and optimize breast cancer survival.