Predicting adherence to tamoxifen for breast cancer adjuvant therapy and prevention

Side effects of low-dose tamoxifen: results from a six-armed randomised controlled trial in healthy women

BACKGROUND

Adherence to adjuvant tamoxifen therapy is suboptimal, and acceptance of tamoxifen for primary prevention is poor. Published results indicate effect of low-dose tamoxifen therapy. Using questionnaire data from a randomised controlled trial, we describe side effects of standard and low-dose tamoxifen in healthy women.

METHODS

In the KARISMA trial, 1440 healthy women were randomised to 6 months of daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. Participants completed a 48-item, five-graded Likert score symptom questionnaire at baseline and follow-up. Linear regression models were used to identify significant changes in severity levels across doses and by menopausal status.

RESULTS

Out of 48 predefined symptoms, five were associated with tamoxifen exposure (hot flashes, night sweats, cold sweats, vaginal discharge and muscle cramps). When comparing these side effects in premenopausal women randomised to low doses (2.5, 5 mg) versus high doses (10, 20 mg), the mean change was 34% lower in the low-dose group. No dose-dependent difference was seen in postmenopausal women.

CONCLUSIONS

Symptoms related to tamoxifen therapy are influenced by menopausal status. Low-dose tamoxifen, in contrast to high-dose, was associated with less pronounced side effects, a finding restricted to premenopausal women. Our findings give new insights which may influence future dosing strategies of tamoxifen in both the adjuvant and preventive settings.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03346200.

Short-term changes in ultrasound tomography measures of breast density and treatment-associated endocrine symptoms after tamoxifen therapy

Although breast density decline with tamoxifen therapy is associated with greater therapeutic benefit, limited data suggest that endocrine symptoms may also be associated with improved breast cancer outcomes. However, it is unknown whether endocrine symptoms are associated with reductions in breast density after tamoxifen initiation. We evaluated treatment-associated endocrine symptoms and breast density change among 74 women prescribed tamoxifen in a 12-month longitudinal study. Treatment-associated endocrine symptoms and sound speed measures of breast density, assessed via novel whole breast ultrasound tomography (m/s), were ascertained before tamoxifen (T0) and at 1-3 (T1), 4-6 (T2), and 12 months (T3) after initiation. CYP2D6 status was genotyped, and tamoxifen metabolites were measured at T3. Using multivariable linear regression, we estimated mean change in breast density by treatment-associated endocrine symptoms adjusting for age, race, menopausal status, body mass index, and baseline density. Significant breast density declines were observed in women with treatment-associated endocrine symptoms (mean change (95% confidence interval) at T1:-0.26 m/s (-2.17,1.65); T2:-2.12 m/s (-4.02,-0.22); T3:-3.73 m/s (-5.82,-1.63); p-trend = 0.004), but not among women without symptoms (p-trend = 0.18) (p-interaction = 0.02). Similar declines were observed with increasing symptom frequency (p-trends for no symptoms = 0.91; low/moderate symptoms = 0.03; high symptoms = 0.004). Density declines remained among women with detectable tamoxifen metabolites or intermediate/efficient CYP2D6 metabolizer status. Emergent/worsening endocrine symptoms are associated with significant, early declines in breast density after tamoxifen initiation. Further studies are needed to assess whether these observations predict clinical outcomes. If confirmed, endocrine symptoms may be a proxy for tamoxifen response and useful for patients and providers to encourage adherence.

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 24-1 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.

Latest generation estrogen receptor degraders for the treatment of hormone receptor-positive breast cancer

INTRODUCTION

The selective estrogen receptor degrader (SERD) and full receptor antagonist provides an important therapeutic option for hormone receptor (HR)-positive breast cancer. Endocrine therapies include tamoxifen, a selective estrogen receptor modulator (SERM), that exhibits receptor agonist and antagonist activity, and aromatase inhibitors that block estrogen biosynthesis but which demonstrate acquired resistance. Fulvestrant, the only currently approved SERD, is limited by poor drug-like properties. A key focus for improving disease management has been development of oral SERDs with optimized target occupancy and potency and superior clinical efficacy.

AREAS COVERED

Using PubMed, clinicaltrials.gov, and congress websites, this review explored the preclinical development and clinical pharmacokinetics from early phase clinical studies (2015 or later) of novel oral SERDs, including giredestrant, amcenestrant, camizestrant, elacestrant, and rintodestrant.

EXPERT OPINION

Numerous oral SERDs are in clinical development, aiming to form the core endocrine therapy for HR-positive breast cancer. Through property- and structure-based drug design of estrogen receptor-binding, antagonism, degradation, anti-proliferation, and pharmacokinetic properties, these SERDs have distinct profiles which impact clinical dosing, efficacy, and safety. Assuming preliminary safety and activity data are confirmed in phase 3 trials, these promising agents could further improve the management, outcomes, and quality of life in HR-positive breast cancer.

Adjuvant endocrine therapy for premenopausal women with breast cancer: Patient adherence and physician prescribing practices in Mexico

BACKGROUND

In resource-constrained settings, data regarding breast cancer patients' adherence to endocrine therapy (ET) and physicians' prescribing practices is limited. This study aims to decrease this knowledge gap in a real-world clinical practice.

METHODS

Premenopausal women with stage 0-III hormone-sensitive breast cancer and receiving adjuvant ET during the past 1-5 years were identified in three Mexican referral centers. Participants' self-reported ET compliance, clinicopathologic characteristics, ET-related knowledge and beliefs, experienced adverse effects, social support, and patient-physician relationships were evaluated. Physician ET prescribing practices were compared with the gold standard according to international and national guidelines to assess clinicians' adherence to standard-of-care prescription.

RESULTS

In total, 95/132 (72%) and 35/132 (27%) participants reported complete and acceptable adherence, respectively. Incomplete adherence was mainly attributed to forgetfulness, adverse effects, and unwillingness to take ET. Being employed/studying (p = 0.042), worrying about long-term ET use (p = 0.031), and experiencing >7 ET-related symptoms (p = 0.018) were associated with incomplete adherence. Guideline-endorsed regimens were prescribed in 84/132 (64%) patients, while the rest should have undergone ovarian function suppression (OFS) but instead received tamoxifen monotherapy.

CONCLUSIONS

Premenopausal Mexican women self-report remarkably high rates of adequate ET adherence. However, a considerable proportion misses ≥1 doses/month, usually because of forgetfulness. Notably, only 64% receive standard-of-care ET due to suboptimal prescription of OFS. Interventions that remind patients to take their ET, refine physicians' knowledge on the importance of OFS in high-risk patients, and increase access to OFS could prove pivotal to enhance optimal ET implementation and adherence, which could translate into improved patient outcomes.

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.

PAX2 promoter methylation and AIB1 overexpression promote tamoxifen resistance in breast carcinoma patients

INTRODUCTION

Disease recurrence is an important obstacle in estrogen receptor positive (ER⁺) tamoxifen treated breast carcinoma patients. Tamoxifen resistance-related molecular mechanisms are not fully understood. Alteration in DNA methylation which contributes to transcriptional regulation of cancer-related genes plays a crucial role in tamoxifen response. In the present study, the contribution of promoter methylation and mRNA expression of PAX2 and AIB1 in the development of breast carcinoma and tamoxifen refractory was assessed.

METHODS

Methylation specific-high resolution melting (MS-HRM) analysis and Real-time quantitative PCR (RT-qPCR) experiment were performed to analyze the promoter methylation and mRNA expression levels of PAX2 and AIB1 genes in 102 breast tumors and adjacent normal breast specimens.

RESULTS

We indicated that PAX2 expression is decreased in breast tissues due to hypermethylation in its promoter region. Compared to the adjacent normal tissues, the tumors exhibited significantly lower relative mRNA levels of PAX2 and increased expression of AIB1. Aberrant promoter methylation of PAX2 and overexpression of AIB1 was observed in tamoxifen resistance patients compared to the sensitive ones. Cox regression analysis exhibited that the increased promoter methylation status of PAX2 and overexpression of AIB1 remained as unfavorable identifiers which influence patients' survival independently.

CONCLUSIONS

Our results revealed that the aberration in PAX2 promoter methylation and AIB1 overexpression are associated with the tamoxifen response in breast carcinoma patients. Further research is needed to demonstrate the potential of using PAX2 and AIB1 expression and their methylation-mediated regulation as predictive or prognostic biomarkers or as a new target therapy for better disease management.

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.

Tamoxifen related side effects and their impact on breast cancer incidence: A retrospective analysis of the randomised IBIS-I trial

BACKGROUND

Studies in the adjuvant setting have shown that endocrine therapy related side effects predict breast cancer recurrence risk. Here, we assess the relationship between early reported side effects and incidence of breast cancer in women randomised to tamoxifen for cancer prevention in the International Breast Intervention Study (IBIS)-I trial.

METHODS

Women randomised to tamoxifen in the IBIS-I trial and for whom side effect status was known at the 6-month follow-up visit were included in this analysis. Side effects included in this analysis were hot flushes, vaginal discharge, and vaginal dryness. The primary endpoint was all breast cancer and secondary endpoint was oestrogen receptor (ER) positive breast cancer. Cox proportional hazard models were used to investigate breast cancer incidence in the tamoxifen group with and without side effects reported within 6 months of randomisation.

RESULTS

Women randomised to tamoxifen and reporting hot flushes at the 6-month follow-up visit had a non-statistically significant increase in breast cancer compared to those without hot flushes (HR = 1.26 (0.98-1.62), P = 0.08). A significant higher breast cancer risk was observed for postmenopausal women who reported hot flushes at the 6-month follow-up visit compared to those without hot flushes (HR = 1.59 (1.12-2.26), P = 0.01). A higher risk was observed for ER-positive breast cancer in postmenopausal women (HR = 1.81 (1.19-2.74), P = 0.01). No significant associations between gynaecological side effects and breast cancer occurrence was observed.

CONCLUSIONS

Overall, no association between side effects reported at 6 months and subsequent breast cancer occurrence was observed. Some side effects might be useful markers for breast cancer occurrence in postmenopausal women.

Improving Adherence to Adjuvant Hormonal Therapy Among Disadvantaged Women Diagnosed with Breast Cancer in South Carolina: Proposal for a Multimethod Study

BACKGROUND

Current clinical guidelines recommend that hormone receptor-positive breast cancer survivors take adjuvant hormonal therapy (AHT) for 5 to 10 years, following the end of definitive treatment. However, fewer than half of patients adhere to the guidelines, and suboptimal adherence to AHT is associated with an increased risk of breast cancer mortality. Research has extensively documented sociodemographic and disease-specific factors associated with adherence to AHT, but very little evidence exists on behavioral factors (eg, knowledge, patient-provider communication) that can be modified and targeted by interventions.

OBJECTIVE

The goal of this study is to develop and test a theory-based, multilevel intervention to improve adherence to AHT among breast cancer survivors from racially and socioeconomically disadvantaged backgrounds (eg, Medicaid-insured). The specific aims are to (1) explore multilevel (eg, patient, health care system) factors that influence adherence to AHT; (2) develop a theory-based, multilevel intervention to improve adherence to AHT; and (3) pilot test and evaluate the intervention developed in Aim 2.

METHODS

For Aim 1, we will recruit breast cancer survivors and health care professionals to participate in semistructured interviews to gain their perspectives about barriers and facilitators to AHT use. We will conduct a directed content analysis of the Aim 1 qualitative interview data. For Aim 2, we will integrate Aim 1 findings and current literature into the design of a multilevel intervention using an Intervention Mapping approach. For Aim 3, we will recruit Medicaid-insured breast cancer survivors to assess the feasibility of the pilot intervention.

RESULTS

From May 2016 to July 2018, we completed interviews with 19 breast cancer survivors and 23 health care professionals in South Carolina. We will conduct a directed content analysis of the qualitative interview data. Results from this analysis will be used, in combination with current literature, to design (Aim 2) and pilot test a theory-based multilevel intervention (Aim 3) in Summer 2021. Results of the pilot are expected for Fall 2021.

CONCLUSIONS

This study will provide a deeper understanding of how to improve adherence to AHT, using a novel and multilevel approach, among socioeconomically disadvantaged breast cancer survivors who often experience disproportionate breast cancer mortality.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/17742.

Simulating Time-Dependent Patterns of Nonadherence by Patients With Breast Cancer to Adjuvant Oral Endocrine Therapy

PURPOSE

Nearly 40% of patients with breast cancer discontinue their adjuvant oral endocrine treatment (ET). We measured discontinuation rates of ET at a comprehensive cancer center. We then used an iterative approach to model patterns of determinants associated with discontinuation of ET.

METHODS

Patients with nonmetastatic breast cancer receiving active adjuvant ET were approached by nurse practitioners to complete an anonymous survey at one time point. We simulated a prospective model by iteratively regressing adverse effects onto adherence status across windowed time periods of 2 to 3 consecutive years, bootstrapping the smaller group of nonadherent patients and subsampling the larger adherent group.

RESULTS

From February to April 2013, 216 participants were enrolled in the study. Forty patients (18.5%) reported that they had discontinued ET during the first 5 years of ET, and an additional four patients (1.9%) missed > 20% of their doses. Using two-sided significance tests, simulations showed that all 13 ET adverse effects and reasons for discontinuation were significantly related to discontinuation at some time point during ET. Worry about ET cost (odds ratio [OR], 1.79), emotional distress (OR, 1.72), and bone and joint pain (OR, 1.69) were the three most impactful reasons for discontinuation, with varying patterns of influence over time.

CONCLUSION

These analyses provide preliminary evidence that there are varying patterns of discontinuation of ET. Although some reasons for discontinuation exerted a steady influence over the 6-year ET trajectory (ie, bone and joint pain), other reasons, such as cost, cognitive complaints, and general dislike of pills, became more important in the later years of ET.

Tamoxifen-related endocrine symptoms in Chinese patients with breast cancer: Study protocol clinical trial (SPIRIT Compliant)

BACKGROUND

Breast cancer is the most prevalent cancer in females and disease recurrence remains a significant problem. To prevent recurrence, tamoxifen is prescribed for at least 5 years. However, among patients who receive tamoxifen, individual responses are highly variable. These responses are affected by the type, frequency, and severity of endocrine symptoms, as well as adherence rates. Polymorphisms in genes involved in the metabolism of tamoxifen (ie, CYP3A4, CYP2D6) may influence responses to tamoxifen. In this study, the inter-relationships among endocrine symptoms, drug adherence, and genetic polymorphisms in Chinese breast cancer patients receiving tamoxifen therapy will be examined. We hypothesize that patients with more severe endocrine symptoms will be less likely to adhere to tamoxifen treatment. In addition, we hypothesize that a relationship will exist between the severity of tamoxifen-induced symptoms and allelic variations in tamoxifen metabolism-related genes. Although many association studies have determined that select genotypes influence the efficacy of tamoxifen, very few studies have investigated for associations between tamoxifen-induced endocrine symptoms and these polymorphisms.

OBJECTIVES

The aim of this study was to characterize genetic polymorphisms in tamoxifen metabolism-associated genes in Chinese women with breast cancer and to explore the inter-relationships between genetic polymorphisms, endocrine symptoms, and adherence to tamoxifen.

METHOD

We will conduct a prospective cohort study that follows 200 Chinese women over 18 months and assess treatment-related symptoms and genetic variations. Endocrine symptoms and drug adherence will be determined through interview-administered standardized questionnaires. Polymorphisms in drug metabolism genes will be determined using real-time polymerase chain reaction based genotyping method. Data will be analyzed to determine associations between allelic variations, endocrine symptoms, and adherence.

DISCUSSION

The proposed study will evaluate for polymorphisms in gene(s) that are associated with tamoxifen-related endocrine symptoms and adherence with tamoxifen. We will explore the relationships between genotypes, endocrine symptoms, and drug adherence in Chinese breast cancer patients. Findings from this study may assist clinicians to identify patients at higher risk for a worse symptom experience and lower adherence rates and enable them to initiate appropriate interventions. In the long term, the findings from this study may be used to develop and test tailored symptom management interventions for these patients.

Promise of Mobile Health Technology to Reduce Disparities in Patients With Cancer and Survivors

Despite recent advances in cancer control, numerous disparities exist in the areas of patient access to care, self-management, and quality of life. However, mobile health technology shows promise as a tool to reduce disparities among patients with cancer and cancer survivors by overcoming such barriers as limited access to providers, difficulty communicating with providers, and inadequate communication between patients and providers regarding symptoms. This narrative review draws on the literature in cancer and noncancer populations to identify factors that create or maintain disparities and to describe opportunities for mobile health technology to reduce disparities.

Compliance with multidisciplinary team meeting management recommendations

OBJECTIVES

The objective of this study was to evaluate patient compliance with management recommendations given by a breast cancer multidisciplinary team (MDT), assess for reasons for noncompliance, and perform an exploratory assessment on breast cancer outcomes in noncompliant patients.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data was undertaken for patients selected by their primary clinician to be discussed at the MDT of Breast Cancer Research Centre-WA in Perth between 1st March 2011 and the 28th February 2016. The primary objective was the rate of compliance with MDT management recommendations. Secondary objectives included factors associated with noncompliance, rate of clinical trial uptake, and impact of treatment noncompliance on breast cancer events in a subgroup of early breast cancer (EBC) patients.

RESULTS AND CONCLUSION

A total of 2614 MDT management recommendations were made for 925 patients. Overall, 92% were compliant with all recommendations given. Clinical trial recruitment was successful in 84.1%. The reasons given for treatment noncompliance were fear of toxicity, choosing an alternative treatment, and treatment inconvenience. In a subset of 337 EBC patients, there was a significantly higher rate of contralateral breast cancer, distant recurrence, and breast cancer-specific death, P = .0016, in those who were noncompliant. Our study demonstrates a high rate of MDT treatment recommendation compliance and clinical trial recruitment. In a subgroup of EBC patients, noncompliance was associated with significantly worse outcomes. Attention to educating patients to minimize their fear of treatment toxicity and ensuring their understanding of evidence-based treatment may lead to lower rates of noncompliance.

Applying machine learning to predict future adherence to physical activity programs

BACKGROUND

Identifying individuals who are unlikely to adhere to a physical exercise regime has potential to improve physical activity interventions. The aim of this paper is to develop and test adherence prediction models using objectively measured physical activity data in the Mobile Phone-Based Physical Activity Education program (mPED) trial. To the best of our knowledge, this is the first to apply Machine Learning methods to predict exercise relapse using accelerometer-recorded physical activity data.

METHODS

We use logistic regression and support vector machine methods to design two versions of a Discontinuation Prediction Score (DiPS), which uses objectively measured past data (e.g., steps and goal achievement) to provide a numerical quantity indicating the likelihood of exercise relapse in the upcoming week. The respective prediction accuracy of these two versions of DiPS are compared, and then numerical simulation is performed to explore the potential of using DiPS to selectively allocate financial incentives to participants to encourage them to increase physical activity.

RESULTS

we had access to a physical activity trial data that were continuously collected every 60 sec every day for 9 months in 210 participants. By using the first 15 weeks of data as training and test on weeks 16-30, we show that both versions of DiPS have a test AUC of 0.9 with high sensitivity and specificity in predicting the probability of exercise adherence. Simulation results assuming different intervention regimes suggest the potential benefit of using DiPS as a score to allocate resources in physical activity intervention programs in reducing costs over other allocation schemes.

CONCLUSIONS

DiPS is capable of making accurate and robust predictions for future weeks. The most predictive features are steps and physical activity intensity. Furthermore, the use of DiPS scores can be a promising approach to determine when or if to provide just-in-time messages and step goal adjustments to improve compliance. Further studies on the use of DiPS in the design of physical activity promotion programs are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01280812 Registered on January 21, 2011.

Prehospital delay and its associated psychosocial factors in patients presenting with acute appendicitis in a southwestern city in China: a single-centre prospective observational study

OBJECTIVE

Prehospital delay is common among patients with acute appendicitis. The aim of this study was to measure the association of a wide range of psychosocial factors with the prehospital delay among adult patients with acute appendicitis in a southwestern city in China.

METHODS

Sociodemographic, clinical, cognitive and psychosocial factors were collected from 421 adult patients with acute appendicitis from November 2016 to December 2017. In addition, factors associated with prehospital delay were determined by binary logistic regression, after adjusting for selected potentially confounding factors.

RESULTS

Only 179 (42.5%) of the 421 patients were transferred to the hospital within 24 hours; the mean prehospital delay was 27.68 hours with a median of 26 hours, while the mean in-hospital delay was 5.16 hours with a median of 5 hours. In the logistic regression analyses, eight variables or subvariables were found to be associated with prehospital delay >24 hours.

CONCLUSION

Delayed presentation for acute appendicitis was associated with older age, living alone, a lack of knowledge of the disease, low social support, an unstable introvert personality trait and negative coping style, intensity of the pain and the symptoms occurring on a workday. A better understanding of the association between psychosocial factors and prehospital delay can help identify patients with acute appendicitis at risk of prehospital delay and lead to the establishment of an effective campaign to promote hospital visits when the symptoms are noticed.

Higher Age Puts Lung Cancer Patients at Risk for Not Receiving Anti-cancer Treatment

PURPOSE

We aimed to determine the demographic and epidemiologic variables that are associated with no treatment in lung cancer patients.

Materials and Methods

Patient data were collected from the Korean National Health Insurance Database. The lung cancer group included patients with an initial diagnosis of lung cancer between January 2009 and December 2014. Treated cases were defined as those that underwent surgery, radiation, or chemotherapy until death, after the diagnosis of lung cancer. Risk of no treatment was calculated by multiple logistic regression analysis.

RESULTS

Among the 2148 new cases of lung cancer from 2009 to 2104, 612 (28.4%) were not treated. Risk of no treatment was higher in the following patients: patients in their 60s (odds ratio [OR], 1.18; 95% confidence interval [CI], 0.75 to 1.84), 70s (OR, 3.64; 95% CI, 2.41 to 5.50), and >80 years old (OR, 16.55; 95% CI, 10.53 to 25.03) than those in their 50s; patients with previous myocardial infarction (OR, 2.07; 95% CI, 1.01 to 4.25) or chronic kidney disease (OR, 2.88; 95% CI, 1.57 to 5.30); and patients diagnosed at a non-referral hospital (OR, 1.40; 95% CI, 1.01 to 1.92) or primary care provider (OR, 1.81; 95% CI, 1.43 to 2.29) compared with referral hospital. Low-income patients receiving Medicaid were 1.75 times (95% CI, 1.14 to 2.68) more likely to forgo treatment than high-income patients (upper 20%). Risk was not associated with sex or the year in which the lung cancer was diagnosed.

CONCLUSION

Age predominantly determines whether patients with lung cancer undergo anti-cancer treatment.

Divergence from osteoporosis screening guidelines in older breast cancer patients treated with anti-estrogen therapy: A population-based cohort study

PURPOSE

Older Breast Cancer (BC) survivors are an increased risk of osteoporosis due to natural aging and long-term cancer treatment-related toxicity. It is well known that anti-estrogen therapy (AET), especially aromatase inhibitors (AI), is associated with rapid bone loss and thus increases the risk of osteoporosis. This study characterizes patterns and predictors of receiving guideline-recommended bone densitometry (BD) screening at AET initiation.

METHODS

A retrospective cohort study (1998-2012) of all women ≥65 years of age initiating AET was designed using claims data from Quebec's universal health care. Associations with BD screening were estimated using a generalized estimating equations regression model, adjusting for clustering of patients within physicians.

RESULTS

Among 16,480 women initiating AET, 36.1% received a baseline BD. Among AI users, the rate was 58.4%. In the multivariate analysis, age, lower socioeconomic status, tamoxifen use, lack of periodic health exam and having a general practitioner as the AET prescriber were associated with lower odds of BD screening. In terms of quality of care-related variables, lack of guideline-appropriate radiotherapy (OR: 0.69 (95% CI, 0.57-0.83), or chemotherapy consideration (0.82 (95% CI, 0.71-0.94)) and non-adherence to AET (0.76 (95% CI, 0.68-0.84)) were associated with lower odds of receiving BD screening. Women diagnosed with BC after 2003 had significantly better odds of being screened.

CONCLUSION

Despite an increase in rates since 2003, BD screening remains suboptimal, especially for women at higher risk of osteoporosis. Coordination of health care and service-delivery monitoring can potentially optimize long-term management of treatment-related toxicity in older BC survivors.

Determinants of non-adherence to adjuvant endocrine treatment in women with breast cancer: the role of comorbidity

PURPOSE

To examine factors associated with non-adherence during 5 years of endocrine treatment, including the possible influence of comorbidity burden and specific medical conditions.

METHODS

From all women diagnosed with stage I-III, ER-positive breast cancer in Stockholm-Gotland, Uppsala-Örebro and Northern Sweden between 2006 and 2009, we included 4645 women who had at least one dispensation of tamoxifen or aromatase inhibitors (AIs) and 5 years of follow-up without distant recurrence. A medical possession ratio of < 80% was used to define non-adherence. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of non-adherence.

RESULTS

During follow-up, 977 (21%) women became non-adherents. Non-adherence was associated with greater comorbidity burden assessed by Charlson comorbidity index (CCI) during follow-up (OR 1.43; 95% CI 1.08-1.88 for ≥ 2 additional scores compared to 0), pre-diagnostic HRT use (OR 1.99; 1.58-2.49), not married (OR 1.42; 1.23-1.64), high educational level (OR 1.25; 1.02-1.53 compared to lowest level), and use of symptom-relieving drugs. HER-2 positivity (OR 0.61; 0.45-0.81) and adjuvant chemotherapy (OR 0.42; 0.35-0.52) were associated with lower odds of non-adherence. Similar patterns were observed for the presence of lymph node metastasis, higher tumour grade, and use of AIs compared to tamoxifen. Myocardial infarction and chronic pulmonary disease was suggested as leading conditions associated with non-adherence in women with increasing CCI.

CONCLUSION

We identified subgroups of women with breast cancer at increased risk of non-adherence. Our findings related to comorbidity suggest the importance of focusing on the presence of specific co-existing conditions when monitoring adherence.

Deconstructing Decisions to Initiate, Maintain, or Discontinue Adjuvant Endocrine Therapy in Breast Cancer Survivors: A Mixed-Methods Study

PURPOSE/OBJECTIVES

Adjuvant endocrine therapy (AET) has been shown to improve survival in hormone receptor-positive breast cancer survivors, but as many as half do not complete recommended treatment. Management of medication-related side effects and engagement with providers are two potentially modifiable factors, but their associations with adherence are not well understood. The aims were to build on survey results to qualitatively explore survivors' experiences with prescribed AET to (a) describe appraisal and management of AET side effects and (b) deconstruct decisions to initiate, discontinue, or maintain AET.
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RESEARCH APPROACH

The authors used a mixed-methods explanatory sequence research design with a qualitative emphasis.
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SETTING

Survivors were recruited from a clinical cancer registry maintained at the University of Texas Southwestern Medical Center, which includes the Harold C. Simmons Comprehensive Cancer Center (National Cancer Institute-designated), in Dallas.
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PARTICIPANTS

452 survivors completed a survey, and 30 took part in telephone interviews.
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METHODOLOGIC APPROACH

Qualitative methods were used in which the authors recorded and transcribed interviews for analysis and used open coding to reduce data into themes.
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FINDINGS

Among adherent survivors, the themes of tolerance of side effects and perseverance were strong. Nonadherent survivors expressed more difficulty managing side effects and perceived fewer benefits when side effects were bothersome. The most common side effects mentioned by all survivors were menopausal symptoms and joint pain; less common side effects were cognitive decline and cardiac distress. Some sought advice from their oncology team. Nonadherent survivors appeared initially motivated to maintain AET but identified a tolerance limit for side effects after which a provider's recommendation was less influential in their decision to maintain or discontinue AET.
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INTERPRETATION

This study elucidated adherence as a complex continuum of behaviors, appraisals, and decision points. These insights may be particularly useful in counseling survivors taking AET and promoting timely delivery of clinical interventions to enhance adherence.
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IMPLICATIONS FOR NURSING

Nurses should be involved in the planning and implementation of clinical interventions to manage side effects and other barriers to AET adherence.

Local Estrogen Synthesis Regulates Parallel Fiber-Purkinje Cell Neurotransmission Within the Cerebellar Cortex

Estrogens affect cerebellar activity and cerebellum-based behaviors. Within the adult rodent cerebellum, the best-characterized action of estradiol is to enhance glutamatergic signaling. However, the mechanisms by which estradiol promotes glutamatergic neurotransmission remain unknown. Within the mouse cerebellum, we found that estrogen receptor activation of metabotropic glutamate receptor type 1a strongly enhances neurotransmission at the parallel fiber-Purkinje cell synapse. The blockade of local estrogen synthesis within the cerebellum results in a diminution of glutamatergic neurotransmission. Correspondingly, decreased estrogen availability via gonadectomy or blockade of aromatase activity negatively affects locomotor performance. These data indicate that locally derived, and not just gonad-derived, estrogens affect cerebellar physiology and function. In addition, estrogens were found to facilitate parallel fiber-Purkinje cell synaptic transmission in both sexes. As such, the actions of estradiol to support cerebellar neurotransmission and cerebellum-based behaviors might be fundamental to understanding the normal processing of activity within the cerebellar cortex.

Tamoxifen synergizes with 4-(E)-{(4-hydroxyphenylimino)-methylbenzene, 1,2-diol} and 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, novel azaresveratrol analogs, in inhibiting the proliferation of breast cancer cells

We have recently shown that 4-(E)-{(4-hydroxyphenylimino)-methylbenzene, 1,2-diol} (HPIMBD) and 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD), novel analogs of resveratrol (Res), selectively inhibited the proliferation of breast cancer cells. In the current study, we tested HPIMBD and TIMBD individually in combination with tamoxifen (Tam) for inhibition of growth of breast cancer cells. Tamoxifen was first tested on non-neoplastic breast epithelial cell lines and its dose that does not inhibit their growth was determined. A combination of this low dose of Tam with either of the Res analogs HPIMBD or TIMBD, resulted in synergistic inhibition of proliferation of breast cancer cells. Both estrogen receptor (ER)-positive and negative breast cancer cell lines responded to the combination. The combination resulted in a substantial decrease in IC50 values of Res analogs in all breast cancer cell lines tested. Mechanistic studies showed a synergistic increase in apoptosis and autophagy genes (beclin-1 and LC3BII/I) with the combination in ER-negative MDA-MB-231 cells. In ER-positive MCF-7 and T47D cells, the mechanism of synergy was found to be inhibition of expression of ERα and oncogene c-Myc. The combination treatment had a synergistic effect in inhibiting the colony forming and spheroid forming ability of cancer cells. Taken together, our findings indicate that a combination of Tam and Res analogs HPIMBD or TIMBD represents a novel approach to enhancing the use of Tam in therapy for breast cancers. Considering the urgent need for novel therapeutic strategies to treat ER-negative breast cancers and overcoming resistance in ER-positive cancers, this combinatorial approach is worthy of continued investigation.

Adherence to endocrine therapy among Chinese patients with breast cancer: current status and recommendations for improvement

BACKGROUND

Postoperative endocrine therapy is known to reduce recurrence and mortality in patients with estrogen receptor (ER)- or progestogen receptor (PR)-positive breast cancer. Correlates and determinants of compliance with endocrine therapy among Chinese patients with breast cancer are not known. The aim of this study was to elucidate the efficacy and adherence of endocrine therapy in China and suggest effective improvements on the adherence.

PATIENTS AND METHODS

We analyzed the survival of 1,110 patients eligible for endocrine therapy and adherence of 699 patients to endocrine therapy. Kaplan-Meier curves, log-rank tests and Cox proportional hazard models were used to evaluate survival, and logistic regression models were used to assess variables associated with treatment adherence.

RESULTS

Long-term endocrine therapy was associated with lower recurrence rate (HR 0.72; 95% CI 0.56-0.93; p=0.013). Adherence to endocrine therapy was only 63.1%. Sociodemographic characteristics of patients, clinical- and medication-related characteristics and patients' attitudes were associated with adherence to endocrine therapy.

CONCLUSION

Adherence to endocrine therapy in Chinese patients with ER+/PR+ breast cancer was <65%. Both patients and physicians should take progressive steps to improve the rate of adherence.

Association of Insurance and Community-Level Socioeconomic Status With Treatment and Outcome of Squamous Cell Carcinoma of the Pharynx

Importance

Community-level socioeconomic status, particularly insurance status, is increasingly becoming important as a possible determinant in patient outcomes.

Objective

To determine the association of insurance and community-level socioeconomic status with outcome for patients with pharyngeal squamous cell carcinoma (SCC).

Design, Setting, and Participants

This study extracted data from more than 1500 Commission on Cancer-accredited facilities collected in the National Cancer Database. A total of 35 559 patients diagnosed with SCC of the pharynx from 2004 through 2013 were identified. The χ2 test, Kaplan-Meier method, and Cox regression models were used to analyze data from April 1, 2016, through April 16, 2017.

Main Outcomes and Measures

Overall survival was defined as time to death from the date of diagnosis.

Results

Among the 35 559 patients identified (75.6% men and 24.4% women; median age, 61 years [range, 18-90 years]), 15 146 (42.6%) had Medicare coverage; 13 061 (36.7%), private insurance; 4881 (13.7%), Medicaid coverage; and 2471 (6.9%), no insurance. Uninsured patients and Medicaid recipients were more likely to be younger, black, or Hispanic; to have lower median household income and lower educational attainment; to present with higher TNM stages of disease; and to start primary treatment at a later time from diagnosis. Those with private insurance (reference group) had significantly better overall survival than uninsured patients (hazard ratio [HR], 1.72; 95% CI, 1.59-1.87), Medicaid recipients (HR, 1.99; 95% CI, 1.88-2.12), or Medicare recipients (HR, 2.07; 95% CI, 1.99-2.16), as did those with median household income of at least $63 000 (reference) vs $48 000 to $62 999 (HR, 1.19; 95% CI, 1.13-1.26), $38 000 to $47 999 (HR, 1.31; 95% CI, 1.24-1.38), and less than $38 000 (HR, 1.51; 95% CI, 1.43-1.59). On multivariable analysis, insurance status and median household income remained independent prognostic factors for overall survival even after accounting for educational attainment, race, Charlson/Deyo comorbidity score, disease site, and TNM stage of disease.

Conclusions and Relevance

Insurance status and household income level are associated with outcome in patients with SCC of the pharynx. Those without insurance and with lower household income may significantly benefit from improving access to adequate, timely medical care. Additional investigations are necessary to develop targeted interventions to optimize access to standard medical treatments, adherence to physician management recommendations, and subsequently, prognosis in these patients at risk.

Risk factors associated with treatment refusal in lung cancer

Background

The incidence of lung cancer is increasing with longer life expectancy. Refusal of active treatment for cancer is prone to cause patients to experience more severe symptoms and shorten survival. The purpose of this study was to define the factors related to refusal or abandonment of active therapy in lung cancer.

Methods

We retrospectively reviewed the data of 617 patients from medical records from 2010 to 2014. Two groups were formed: 149 patients who refused anti‐cancer treatment and allowed only palliative care were classified into the non‐treatment group, while the remaining 468 who received anti‐cancer treatment were classified into the treatment group.

Results

The groups differed significantly in age, employment, relationship status, number of offspring, educational status, body mass index, presence of chest and systemic symptoms, Charlson Comorbidity Index, Eastern Cooperative Oncology Group score, and tumor node metastasis stage (P < 0.05). In logistic regression analysis, age (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.07–1.13), educational status lower than high school (OR 1.95, 95% CI 1.2–3.2), no history of surgery (OR 2.29, 95% CI 1.4–3.7), body mass index < 18.5 (OR 2.49, 95% CI 1.3–4.7), and a high Eastern Cooperative Oncology Group score of 3 or 4 (OR 5.02, 95% CI 2.3–10.8) were significant factors for refusal of cancer treatment.

Conclusion

Individual factors, such as old age, low educational status, low weight, and poor performance status can influence refusal of cancer treatment in patients with lung cancer, and should be considered prior to consultation with patients.

Tamoxifen Acceptance and Adherence among Patients with Ductal Carcinoma In Situ (DCIS) Treated in a Multidisciplinary Setting

Tamoxifen and other endocrine agents have proven benefits for women with ductal carcinoma in situ (DCIS), but low patient acceptance is widely reported. We examined factors associated with tamoxifen acceptance and adherence among DCIS patients who received a recommendation for therapy in a multidisciplinary setting. Using our institutional database, we identified women diagnosed with DCIS, 1998 to 2009, who were offered tamoxifen. We recorded data on demographics, tumor and therapy variables, tamoxifen acceptance, and adherence to therapy for ≥4 years. Univariable and multivariable analyses were conducted using logistic regression to identify factors specific to each group that were related to acceptance and adherence. A total of 555 eligible women identified, of whom 369 were offered tamoxifen; 298 (81%) accepted, among whom 214 (72%) were adherent, 59 of 298 (20%) were nonadherent, and for 25 (8%), adherence was undetermined. After stepwise elimination in adjusted logistic regression models, acceptance of breast radiotherapy was associated with acceptance of tamoxifen [OR, 2.22; 95% confidence interval (CI), 1.26-3.90; P < 0.01], as was a medical oncology consultation (OR, 1.76; 95% CI, 0.99-3.15; P = 0.05). Insured patients were more likely to adhere to tamoxifen (OR, 6.03; 95% CI, 2.60-13.98; P < 0.01). The majority of nonadherent women (n = 38/56, 68%) discontinued the drug during the first year of treatment with 48 (86%) citing adverse effect(s) as the reason. In a multidisciplinary, tertiary care setting, we observed relatively high rates of acceptance and adherence of tamoxifen. Acceptance of tamoxifen and radiotherapy were associated, and adherence was influenced by insurance status.Key Message: Tamoxifen acceptance and adherence following resection of DCIS of the breast is related to acceptance of radiotherapy and may be improved by confirmation of the recommendation by a medical oncologist. Despite the low cost of tamoxifen, adherence to therapy is significantly impacted by lack of insurance; those who discontinue therapy report adverse effects as a major reason. Cancer Prev Res; 10(7); 389-97. ©2017 AACR.

Endocrine therapy initiation, discontinuation and adherence and breast imaging among 21-gene recurrence score assay-eligible women under age 65

BACKGROUND

Aside from chemotherapy utilization, limited data are available on the relationship between gene expression profiling (GEP) testing and breast cancer care. We assessed the relationship between GEP testing and additional variables and the outcomes of endocrine therapy initiation, discontinuation and adherence, and breast imaging exams in women under age 65 years.

METHODS

Data from five state cancer registries were linked with claims data and GEP results. We assessed variables associated with survivorship care outcomes in an incident cohort of 5014 commercially insured women under age 65 years, newly diagnosed with stage I or II hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2) non-positive breast cancer from 2006 to 2010.

RESULTS

Among tested women, those with high Oncotype DX® Breast Recurrence Score® (RS) were significantly less likely to initiate endocrine therapy than women with low RS tumors (OR 0.40 (95% CI 0.20 to 0.81); P = 0.01). Among all test-eligible women, receipt of Oncotype DX testing was associated with a greater likelihood of endocrine therapy initiation (OR 2.48 (95% CI 2.03 to 3.04); P <0.0001). The odds of initiation were also significantly higher for tested vs. untested women among women who did not initiate chemotherapy within six months of diagnosis (OR 3.25 (95% CI 2.53 to 4.16)), with no effect in women who received chemotherapy. Discontinuation and adherence and breast imaging exams were unrelated to tested status or RS.

CONCLUSIONS

Lower endocrine therapy initiation rates among women with high RS tumors and among untested women not receiving chemotherapy are concerning, given its established efficacy. Additional research is needed to suggest mechanisms to close this gap.

Factors Associated With Early Discontinuation of Study Treatment in the Mammary Prevention.3 Breast Cancer Chemoprevention Trial

Purpose

Aromatase inhibitors are established breast cancer chemoprevention interventions. However, nonadherence remains a significant challenge. We investigated the association between worsening menopause-specific quality of life, baseline participant characteristics, and early treatment discontinuation within the Mammary Prevention.3 (MAP.3) breast cancer prevention trial.

Methods

In the MAP.3 randomized, placebo-controlled trial evaluating exemestane, participants completed the Menopause-Specific Quality of Life Questionnaire (MENQOL) at entry and at 6 months. Multivariable log-binomial regression was used to assess the associations of baseline participant characteristics and clinically meaningful worsening in menopause-specific quality of life (QOL) with treatment discontinuation at 1 year.

Results

Of the 4,501 participants eligible for this analysis, 724 (17%) discontinued assigned treatment within the first year of random assignment of treatment (19% of the exemestane group and 13% of the placebo group). Between 19% and 35% of women experienced a clinically meaningful worsening in the vasomotor, sexual, physical, and psychosocial domains of the MENQOL within 6 months of treatment initiation. Regardless of receiving exemestane or not, experiencing a worsening in any MENQOL domain or, especially, overall menopause-specific QOL, was associated with early treatment discontinuation (relative risk, 1.79; 95% CI, 1.53 to 2.10 for overall worsening). Assignment to exemestane, having a smoking history, and current employment also were significantly associated with early discontinuation.

Conclusion

Negative changes in menopause-specific QOL influence a woman’s decision to stop chemoprevention therapy. Attention to such symptoms may improve QOL and potentially improve chemoprevention adherence.

Influence of insurance status and income in anaplastic astrocytoma: an analysis of 4325 patients

To determine the impact of insurance status and income for anaplastic astrocytoma (AA). Data were extracted from the National Cancer Data Base. Chi square test, Kaplan-Meier method, and Cox regression models were employed in SPSS 22.0 (Armonk, NY: IBM Corp.) for data analyses. 4325 patients with AA diagnosed from 2004 to 2013 were identified. 2781 (64.3%) had private insurance, 925 (21.4%) Medicare, 396 (9.2%) Medicaid, and 223 (5.2%) were uninsured. Those uninsured were more likely to be Black or Hispanic versus White or Asian (p < 0.001), have lower median income (p < 0.001), less educated (p < 0.001), and not receive adjuvant chemoradiation (p < 0.001). 1651 (38.2%) had income ≥$63,000, 1204 (27.8%) $48,000-$62,999, 889 (20.5%) $38,000-$47,999, and 581 (13.4%) had income <$38,000. Those with lower income were more likely to be Black or Hispanic versus White or Asian (p < 0.001), uninsured (p < 0.001), reside in a rural area (p < 0.001), less educated (p < 0.001), and not receive adjuvant chemoradiation (p < 0.001). Those with private insurance had significantly higher overall survival (OS) than those uninsured, on Medicaid, or on Medicare (p < 0.001). Those with income ≥$63,000 had significantly higher OS than those with lower income (p < 0.001). On multivariate analysis, age, insurance status, income, and adjuvant therapy were independent prognostic factors for OS. Being uninsured and having income <$38,000 were independent prognostic factors for worse OS in AA. Further investigations are warranted to help determine ways to ensure adequate medical care for those who may be socially disadvantaged so that outcome can be maximized for all patients regardless of socioeconomic status.

Geographic disparities in adherence to adjuvant endocrine therapy in Appalachian women with breast cancer

BACKGROUND

Appalachia is a largely rural, mountainous, poor and underserved region of the United States. Adherence to adjuvant endocrine therapy among Appalachian women with breast cancer is suboptimal.

OBJECTIVES

To explore small-area geographic variations and clustering patterns of breast cancer patient adherence to adjuvant endocrine therapy and associated factors in Appalachia.

METHODS

In this retrospective study, we analyzed Medicare claims data linked with cancer registries from four Appalachian states (PA, OH, KY, and NC) in 2006-2008. We included adult women who were diagnosed with stage I-III, hormone-receptor positive, primary breast cancer and who newly started adjuvant endocrine therapy after the primary treatment for breast cancer. Hot spot analysis was conducted to explore geographic variations in adjuvant endocrine therapy adherence. Geographically weighted logistic regression (GWLR) was used to examine whether the impacts of factors associated with adherence varied across the region.

RESULTS

Breast cancer patients living in PA and OH showed higher adherence to adjuvant endocrine therapy than those living in KY and NC. We identified clusters of high adherence in most of PA but poor adherence in Erie County, PA and in Buncombe, Transylvania, Henderson, and Polk Counties, NC. Adherence to adjuvant endocrine therapy was significantly associated with the Health Professional Shortage Area designation, catastrophic coverage, dual-eligibility status of Medicaid and Medicare, adjuvant endocrine therapy drug class, and side effects. And among these factors, the impacts of dual-eligibility status and the use of pain medications to treat side effects on adherence were more pronounced in KY and NC than in PA.

CONCLUSIONS

There were significant geographic disparities in adherence to adjuvant endocrine therapy in the Appalachian counties in PA, OH, KY, and NC. This study explored these geographic areas with poor adherence as well as geographically varying effects of predictors on adherence; our results may provide more localized information that may be used to improve adjuvant therapy use and breast cancer care in these high-risk and underserved areas.

Factors involved in the delay of treatment initiation for cervical cancer patients: A nationwide population-based study

Cervical cancer ranks as the fourth leading cause of cancer death in women worldwide. In Taiwan, although the universal health insurance system has achieved 99.9% coverage and ensured easy access to medical care, some cervical cancer patients continue to delay initiation of definitive treatment after diagnosis. This study focused on cervical cancer patients who delayed treatment for at least 4 months, and examined the characteristics, related factors, and survival in these patients.Data on patients with a new confirmed diagnosis of cervical cancer by the International Federation of Gynecology and Obstetrics (FIGO) staging system between 2005 and 2010 were obtained from the National Health Insurance Research Database and the Taiwan Cancer Registry. Logistic regression analysis was performed to analyze the association of various factors with treatment delay. The Cox proportional hazards model was used to analyze the effects of various factors on mortality risk.The rate of treatment delay for cervical cancer decreased steadily from 6.46% in 2005 to 2.48% in 2010. Higher rates of treatment delay were observed among patients who were aged ≥75 years (9.91%), had severe comorbidity, had stage IV (9.50%), diagnosing hospital level at nonmedical center, or at public hospital ownership. Factors that correlated with treatment delay were age ≥75 years (odds ratio [OR] = 2.42), higher comorbidity Charlson comorbidity index (CCI) 4-6, or ≥7 (OR = 1.60, 2.00), cancer stage IV (OR = 2.60), the diagnosing hospital being a regional, district hospital, or other (OR = 3.00, 4.01, 4.60), and at public hospital ownership. Those who delayed treatment had 2.31 times the mortality risk of those who underwent timely treatment (P < 0.05).Delayed cervical cancer treatment in Taiwan was associated with age, comorbidity, cancer stage, diagnosing hospital level, and hospital ownership. Delaying treatment for ≥4 months substantially raised mortality risk in cervical cancer patients.

Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis

BACKGROUND

Preventive therapy is a risk reduction option for women who have an increased risk of breast cancer. The effectiveness of preventive therapy to reduce breast cancer incidence depends on adequate levels of uptake and adherence to therapy. We aimed to systematically review articles reporting uptake and adherence to therapeutic agents to prevent breast cancer among women at increased risk, and identify the psychological, clinical and demographic factors affecting these outcomes.

DESIGN

Searches were carried out in PubMed, CINAHL, EMBASE and PsychInfo, yielding 3851 unique articles. Title, abstract and full text screening left 53 articles, and a further 4 studies were identified from reference lists, giving a total of 57. This review was prospectively registered with PROSPERO (CRD42014014957).

RESULTS

Twenty-four articles reporting 26 studies of uptake in 21 423 women were included in a meta-analysis. The pooled uptake estimate was 16.3% [95% confidence interval (CI) 13.6-19.0], with high heterogeneity (I(2) = 98.9%, P < 0.001). Uptake was unaffected by study location or agent, but was significantly higher in trials [25.2% (95% CI 18.3-32.2)] than in non-trial settings [8.7% (95% CI 6.8-10.9)] (P < 0.001). Factors associated with higher uptake included having an abnormal biopsy, a physician recommendation, higher objective risk, fewer side-effect or trial concerns, and older age. Adherence (day-to-day use or persistence) over the first year was adequate. However, only one study reported a persistence of ≥ 80% by 5 years. Factors associated with lower adherence included allocation to tamoxifen (versus placebo or raloxifene), depression, smoking and older age. Risk of breast cancer was discussed in all qualitative studies.

CONCLUSION

Uptake of therapeutic agents for the prevention of breast cancer is low, and long-term persistence is often insufficient for women to experience the full preventive effect. Uptake is higher in trials, suggesting further work should focus on implementing preventive therapy within routine care.

Symptoms and QOL as Predictors of Chemoprevention Adherence in NRG Oncology/NSABP Trial P-1

BACKGROUND

Tamoxifen provides a 50% reduction in the incidence of breast cancer (BC) among high-risk women, yet many do not adhere to the five-year course of therapy. Using the prospective double-blind National Surgical Adjuvant Breast and Bowel Project P-1 study, we evaluated whether participant-reported outcomes were associated with drug adherence and whether baseline behavioral risk factors modified those associations.

METHODS

P-1 participants were randomly assigned to placebo vs tamoxifen (20mg/day). Mixed effects logistic regression was used to evaluate whether baseline or three-month SF-36 quality of life (QOL) mental and physical component summaries (MCS, PCS), and participant-reported symptoms (gynecologic, vasomotor, sexual, and other) predicted 12-month drug adherence (76-100% of assigned medication). The evaluation accounted for age, treatment, estimated breast cancer risk, education, baseline smoking, alcohol consumption, and obesity. All statistical tests were two-sided.

RESULTS

Participants enrolled at least three years before trial unblinding and without medically indicated discontinuation before 12 months were eligible for the present analyses (n = 10 576). At 12 months, 84.3% were adherent. Statistically significant predictors of adherence were: three-month MCS (odds ratio [OR] = 1.15 per 10 points, 95% confidence interval [CI] = 1.06 to 1.25); three-month gynecologic symptoms among moderate alcohol drinkers (OR = .79, 95% CI = 0.72 to 0.88); baseline vasomotor symptoms among participants assigned tamoxifen (OR = .88, 95% CI = 0.80 to 0.97); and three-month sexual symptoms among younger participants (OR = .89 at age 41 years, 95% CI = 0.80 to 0.99). The strongest association was with three-month other symptoms (OR = .77, 95% CI = 0.63 to 0.93). PCS was not associated with adherence. Symptom and QOL associations were not modified by smoking or obesity.

CONCLUSIONS

Promoting QOL and managing symptoms early in therapy may be important strategies to improve adherence.

Awareness of preventive medication among women at high risk for breast cancer and their willingness to consider transdermal or oral tamoxifen: a focus group study

Background

Despite demonstrated efficacy, acceptance of selective estrogen receptor modulators (SERMs), such as tamoxifen, for breast cancer risk reduction remains low. Delivering SERMs via local transdermal therapy (LTT) could significantly reduce systemic effects and therefore may increase acceptance. We aim to assess women’s knowledge of breast cancer prevention medications and views on LTT of SERMs.

Methods

Focus groups were conducted with healthy women identified through the comprehensive breast center of a large urban cancer institution. Group discussions covered risk perceptions, knowledge of and concerns about risk reducing medications. Participants reported their perceived risk for breast cancer (average, below/above average), preference for SERMs in a pill or gel form, risk factors, and prior physician recommendations regarding risk-reducing medicines. Participants’ breast cancer risk was estimated using tools based on the Gail Model. Trained personnel examined all qualitative results systematically; risk perceptions and preferred method of medication delivery were tallied quantitatively.

Results

Four focus groups (N = 32) were conducted. Most participants had at least a college degree (78.2 %) and were of European (50 %) or African ancestry (31 %). The majority (72 %) were at elevated risk for breast cancer; approximately half of these women perceived themselves to be at elevated risk. Few participants had prior knowledge of preventive medications. The women noted a number of concerns about LTT, including dosage, impact on day-to-day life, and side effects; nonetheless, over 90 % of the women stated they would prefer LTT to a pill.

Conclusion

Awareness of preventive medications was low even in a highly educated sample of high-risk women. If given a choice in the route of administration, most women preferred a gel to a pill, anticipating fewer side effects. Future work should focus on demonstrating equivalent efficacy and reduced toxicity of topical over oral medications and on raising awareness of chemopreventive options for breast cancer.

Impact of Fertility Concerns on Tamoxifen Initiation and Persistence

BACKGROUND

Adjuvant tamoxifen reduces breast cancer recurrence risk and mortality; however, initiation and treatment persistence are poor for younger patients. We hypothesized that a unique set of factors, including fertility concerns, would contribute to the poor tamoxifen use among premenopausal patients.

METHODS

From 2007 to 2012, 515 premenopausal patients younger than age 45 years, with stage 0 to III hormone receptor-positive breast cancer, for whom tamoxifen was recommended, were identified. Clinical and pathologic tumor characteristics, treatment regimens, and fertility concerns were recorded. Clinical factors associated with tamoxifen noninitiation and discontinuation were identified using univariate and multivariable analysis. After the recommendation for tamoxifen, patient reasons for tamoxifen noninitiation or discontinuation were also documented. All statistical tests were two-sided.

RESULTS

Based on multivariable analysis, fertility concerns were statistically associated with both noninitiation (odds ratio = 5.04, 95% confidence interval (CI) = 2.29 to 11.07) and early discontinuation (hazard ratio = 1.78, 95% CI = 1.09 to 3.38) of tamoxifen. Other independent predictors of noninitiation included a diagnosis of ductal carcinoma in situ, declining radiation, and not receiving chemotherapy (stage I-III). Additionally, smoking and not receiving radiation therapy were statistically significant predictors of early withdrawal from therapy. Primary patient reasons for noninitiation and early discontinuation included concerns about side effects and fertility.

CONCLUSION

This study provided insight into factors associated with tamoxifen use for reproductive-aged breast cancer survivors, with a new focus on fertility. Fertility concerns negatively impacted tamoxifen initiation and continuation among premenopausal patients. Interventions to optimize treatment initiation and persistence for young cancer patients should include access to fertility preservation options.

Reasons for nonadherence to tamoxifen and aromatase inhibitors for the treatment of breast cancer: a literature review

Despite improved breast cancer survival rates with the use of tamoxifen and aromatase inhibitors, patients remain at risk for cancer recurrence and mortality because of nonadherence to medication. The objective of this review was to identify factors associated with nonadherence among patients with breast cancer. Electronic databases were searched for studies, and potentially relevant studies were retrieved and assessed for eligibility. Potential factors associated with nonadherence were identified, and they included patient-related factors (e.g., patient beliefs and knowledge, fear of adverse effects, forgetfulness, smoking, age, race), therapy-related factors (e.g., duration, side effects, additional prescribed medications, treatment interfering with lifestyle), healthcare system factors (e.g., patient/provider relationships), socioeconomic factors (e.g., medication costs, burden, scheduling problems, religion, marital status), and disease-related factors (e.g., comorbidities, stage of breast cancer). Those findings highlight the need for development of interventions to promote long-term adherence in patients with breast cancer.

Adjuvant therapy use among Appalachian breast cancer survivors

There is a paucity of literature systemically examining the effects of access to cancer care resources on adjuvant endocrine therapy (AET) use behaviors, especially in underserved regions such as the Appalachian region in the United States, where gaps in healthcare access are well documented. The objectives of this study were to explore AET adherence and persistence in Appalachia, delineate the effects of access to care cancer on adherence/persistence, and evaluate the influences of adherence and persistence on overall survival.A retrospective cohort study from 2006 to 2008 was conducted among female breast cancer survivors living in the Appalachian counties of 4 states (PA, OH, KY, and NC). We linked cancer registries to Medicare claims data and included patients with invasive, nonmetastatic, hormone-receptor-positive breast cancer who received guideline-recommended AET. Medication adherence was defined as corresponding to a Medication Possession Ratio (MPR) ≥0.8 and logistic regression was utilized to assess predictors of adherence. Medication nonpersistence was defined as the discontinuation of drugs after exceeding a 60-day medication gap, and multivariate adjusted estimates of nonpersistence were obtained using the Cox proportional hazards (PH) model.About 31% of the total 428 patients were not adherent to AET, and 30% were not persistent over an average follow-up period of 421 days. Tamoxifen, relative to aromatase inhibitors, was associated with higher odds of adherence (odds ratio = 2.82, P < 0.001) and a lower risk of nonpersistence (hazard ratio = 0.40, P < 0.001). Drug-related side effects like pain may be an important factor leading to nonadherence and early discontinuation. In addition, aromatase inhibitor (AI) adherence and persistence were significantly influenced by out-of-pocket drug costs, dual eligibility status, and coverage gaps. Nonadherence to and nonpersistence with AET were associated with higher risks of all-cause mortality.Our findings of suboptimal AET adherence/persistence in Appalachia as well as positive associations between AET adherence/persistence and overall survival outcomes further underscore the importance of ensuring appropriate AET use in this population to reduce breast cancer mortality disparities. Our findings also suggest that intervention strategies focusing on individualized treatment and medication-related factors may improve adjuvant treatment use.

Predictors of Discontinuation of Adjuvant Hormone Therapy in Patients With Breast Cancer

PURPOSE

To identify predictors of discontinuation of adjuvant hormone therapy in patients with breast cancer.

PATIENTS AND METHODS

We conducted a record-linkage study based on data from Stockholm-Gotland Breast Cancer Register, Swedish Prescribed Drug Register, and self-reported questionnaire. Women diagnosed with breast cancer between 2005 and 2008 in Stockholm, Sweden, were prospectively followed for 5 years until 2013, starting from their first prescription of tamoxifen or aromatase inhibitors (N = 3,395).

RESULTS

Family history of ovarian cancer (hazard ratio [HR], 1.55; 95% CI, 1.19 to 2.02); younger (< 40 years; HR, 1.39; 95% CI, 1.08 to 1.78) and older (≥ 65 years; HR, 1.15; 95% CI, 1.03 to 1.28) age; higher Charlson comorbidity index (≥ 2 v 0; HR, 1.35; 95% CI, 1.03 to 1.76); and use of analgesics (HR, 1.33; 95% CI, 1.16 to 1.52), hypnotics/sedatives (HR, 1.24; 95% CI, 1.07 to 1.43), GI drugs (HR, 1.25; 95% CI, 1.08 to 1.43), and hormone replacement therapy (HR, 1.27; 95% CI, 1.08 to 1.49) were identified as baseline predictors for hormonal treatment discontinuation. Use of analgesics (HR, 1.22; 95% CI, 1.08 to 1.37), hypnotics/sedatives (HR, 1.21; 95% CI, 1.07 to 1.37), antidepressants (HR, 1.22; 95% CI, 1.06 to 1.40), or GI drugs (HR, 1.27; 95% CI, 1.13 to 1.43), and switching therapy between tamoxifen and aromatase inhibitors (HR, 1.50; 95% CI, 1.23 to 1.83) during the first year of hormonal treatment were associated with increased risk of discontinuation during the next 4 years.

CONCLUSION

Predictors identified in our study can be used in developing targeted intervention to prevent adjuvant hormone therapy discontinuation and subsequently to improve breast cancer outcomes.

Racial/Ethnic and socioeconomic disparities in endocrine therapy adherence in breast cancer: a systematic review

We examined the current literature to understand factors that influence endocrine therapy (ET) adherence among racial/ethnic and socioeconomic subpopulations of breast cancer patients. We searched PubMed and PsycINFO databases for studies from January 1, 1978, to June 20, 2014, and January 1, 1991, to June 20, 2014, respectively, and hand-searched articles from relevant literature reviews. We abstracted and synthesized results within a social ecological framework. Fourteen articles met all inclusion criteria. The majority of included articles reported significant underuse of ET among minority and low-income women. Modifiable intrapersonal, interpersonal, and community-level factors are associated with ET use, and these factors vary across subgroups. Both race/ethnicity and socioeconomic status are associated with ET use in most settings. Variation in factors associated with ET use across subgroups indicates the need for more nuanced research and targeted interventions among breast cancer patients.

Adherence to adjuvant endocrine therapy for breast cancer: importance in women with low income

There are wide disparities in breast cancer-specific survival by patient sociodemographic characteristics. Women of lower income, for instance, have higher relapse and death rates from breast cancer. One possible contributing factor for this disparity is low use of adjuvant endocrine therapy-an extremely efficacious therapy in women with early stage, hormone receptor positive breast cancer, the most common subtype of breast cancer. Alone, adjuvant endocrine therapy decreases breast cancer recurrence by 50% and death by 30%. Data suggest that low use of adjuvant endocrine therapy is a potentially important and modifiable risk factor for poor outcome in low-income breast cancer patients.

Factors associated to persistence with hormonal therapy in women with breast cancer

OBJECTIVE

To analyze factors associated with persistence to breast cancer hormone therapy in order to contribute to the quality of care improvement.

METHODS

Retrospective longitudinal study, based on secondary data. A cohort of 5,861 women with breast cancer registered in different datasets of the Brazilian National Cancer Institute and the Brazilian Unified Health System were analyzed. All women were treated at this hospital, which provides free medication, and the follow-up period was from January 2004 to October 2010. Sociodemographic, behavioral, and clinical variables, as well as aspects of lifestyle and health care, were considered in the explanation of variations in the persistence to hormone therapy, applying the Kaplan-Meier method and the Cox proportional hazard model.

RESULTS

Overall persistence to hormone therapy was 79.0% at the end of the first year, and 31.0% in five years of treatment. The risk of discontinuing hormone therapy was higher among women under 35 years old, with more advanced disease (stages III and IV), alcohol drinkers, those undergoing chemotherapy, and for each additional hospitalization, exam performed, and month between diagnosis and beginning of treatment. In the opposite direction, the risk of discontinuity was lower among women who had at least finished high school, those with partner, with a family history of cancer, those who had undergone breast surgery, and who had outpatient visits to a Mastologist, and a Clinical Oncologist.

CONCLUSIONS

The majority of the women with breast cancer (69.0%) do not persist with hormone treatment for the five years recommended, increasing the risk of inadequate clinical results. The results show aspects of care that can provide better results.

Factors influencing treatment adherence and discontinuation in women with breast cancer

SUMMARY 

Although all aspects of breast cancer care rely to some extent on patient behaviors, the endocrine therapies, which are orally administered at home, are the most impacted by nonadherence and nonpersistence. A variety of issues can interfere with a breast cancer patient's adherence and persistence including the following: sociodemographic factors; healthcare team and system-related factors (such as inadequate visit time and poor medication distribution services); condition-related factors (such as prognosis); therapy-related factors (such as side effects); and patient-related factors (such as attitudes, beliefs, perceptions, and expectations). In our review, we describe evidence regarding the most powerful factors mediating adherence and persistence in breast cancer patients, and explore potential interventions to reduce nonadherence and nonpersistence, primarily based on data in patients taking adjuvant endocrine therapy.

Risk-benefit profiles of women using tamoxifen for chemoprevention

BACKGROUND

Tamoxifen has been US Food and Drug Administration-approved for primary prevention of breast cancer since 1998 but has not been widely adopted, in part because of increased risk of serious side effects. Little is known about the risk-benefit profiles of women who use chemoprevention outside of a clinical trial. We examined characteristics associated with initiation and discontinuation of tamoxifen for primary prevention of breast cancer within a large cohort of women with a first-degree family history of breast cancer.

METHODS

This research was conducted within The Sister Study, a cohort of 50884 US and Puerto Rican women age 35 to 74 years enrolled from 2003 to 2009. Eligible women were breast cancer-free at enrollment and had a sister who had been diagnosed with breast cancer. Participants reported tamoxifen use, ages started and stopped taking tamoxifen, and total duration of use at enrollment. We identified 788 tamoxifen users and 3131 nonusers matched on age and year of enrollment who had no history of contraindicating factors (stroke, transient ischemic attack, cataract, endometrial or uterine cancer). Characteristics associated with tamoxifen initiation were evaluated with multivariable conditional logistic regression. All statistical tests were two-sided.

RESULTS

Based on published risk-benefit indices, 20% of women who used tamoxifen had insufficient evidence that the benefits of tamoxifen outweigh the risk of serious side effects. After 4.5 years, 46% of women had discontinued tamoxifen.

CONCLUSIONS

While the majority of women who used tamoxifen for primary prevention of breast cancer were likely to benefit, substantial discontinuation of tamoxifen before five years and use by women at risk of serious side effects may attenuate benefits for breast cancer prevention.

The use of Chinese herbal products and its influence on tamoxifen induced endometrial cancer risk among female breast cancer patients: a population-based study

ETHNOPHARMACOLOGICAL RELEVANCE

The increased practice of traditional Chinese medicine (TCM) worldwide has raised concerns regarding herb-drug interactions. The purpose of our study was to analyze the use of Chinese herbal products (CHPs) and to estimate the influence of the use of CHP on tamoxifen induced endometrial cancer risk among female breast cancer patients in Taiwan.

METHODS

All patients newly diagnosed with invasive breast cancer receiving tamoxifen treatment from January 1, 1998 to December 31, 2008 were selected from the National Health Insurance Research Database. The usage, frequency of service, and CHPs prescribed among the 20,466 tamoxifen-treated female breast cancer patients were analyzed. The logistic regression method was employed to estimate the odds ratios (ORs) for utilization of CHPs. Cox proportional hazard regression was performed to calculate the hazard ratios (HRs) for subsequent endometrial cancer for CHP non-users and CHP users among female breast cancer patients who had undergone tamoxifen treatment.

RESULTS

More than half of the subjects had ever used a CHP. Jia-Wei-Xiao-Yao-San (Augmented Rambling Powder) and Shu-Jing-Huo-Xue-Tang (Channel-Coursing Blood-Quickening Decoction) were the two most commonly used CHPs. The HR for the development of endometrial cancer among CHP users was 0.50-fold (95% CI=0.38-0.64) compared to that of CHP non-users.

CONCLUSION

More than half of the study subjects had ever used a CHP. Jia-Wei-Xiao-Yao-San was the most commonly used CHP. Among female breast cancer patients who had undergone tamoxifen therapy, CHP consumption decreased the risk of subsequent endometrial cancer. Exploring potential Chinese herb-tamoxifen interactions and integrating both healthcare approaches are beneficial to the overall health outcomes of tamoxifen-treated female breast cancer patients.

Factors associated with lung cancer patients refusing treatment and their survival: a national cohort study under a universal health insurance in Taiwan

Background

Lung cancer is the leading cause mortality among all cancers in Taiwan. Although Taiwan offers National Health Insurance (NHI), occasionally, patients refuse treatment. This study examined the patient characteristics and factors associated with lung cancer patients refusing cancer treatment in four months after cancer diagnosed and compared the survival differences between treated and non-treated patients.

Methods

The study included 38584 newly diagnosed lung cancer patients between 2004 and 2008, collected from the Taiwan Cancer Registry, which was linked with NHI research database and Cause of Death data set. Logistic regression was conducted to analyze factors associated with treatment refusal. The Cox proportional hazards model was used to examine the effects of treatment and non-treatment on patient survival and the factors affecting non-treatment patient survival.

Results

Among the newly diagnosed cancer patients, older adults, or those who had been diagnosed with other catastrophic illnesses, an increased pre-cancer Charlson Comorbidity Index (CCI) score, and advanced stage cancer exhibited an increased likelihood of refusing treatment. Compared with treated patients, non-treated patients showed an increased mortality risk of 2.09 folds. The 1-year survival rate of treated patients (53.32%) was greater than that of non-treated patients (21.44%). Among the non-treated patients, those who were older, resided in lowly urbanized areas, had other catastrophic illnesses, a CCI score of ≥4, advanced cancer, or had received a diagnosis from a private hospital exhibited an increased mortality risk.

Conclusions

Despite Taiwan's NHI system, some lung cancer patients choose not to receive cancer treatment and the mortality rate for non-treated patients is significantly higher than that of patients who undergo treatment. Therefore, to increase the survival rate of cancer patients, treatment refusal should be addressed.

Adherence to hormone therapy among women with breast cancer

Background

Despite the excellent results obtained with hormone therapy, the long treatment period and the side effects associated with its use make patient adherence difficult. Moreover, certain aspects of health care can mitigate or exacerbate non-adherence. This study aimed to identify the factors associated with adherence to hormone therapy for breast cancer, with the goal of contributing to the reformulation of the care process and to improvements in outcomes.

Method

This was a retrospective longitudinal study based on secondary data. The study integrated and analyzed data from a cohort of 5,861 women with breast cancer who were identified in the databases of the Brazilian National Cancer Institute [Instituto Nacional de Câncer - INCA] and the Unified Health System [Sistema Único de Saúde - SUS]. All of the patients were treated at INCA, which dispenses free medication, and the follow-up period lasted from 01/01/2004 to 10/29/2010. The outcome of interest was hormone treatment adherence, which was defined as the possession of medication, and a logistic regression model was employed to identify the socio-demographic, behavioral, clinical, and health care variables that were independently associated with the variations in this outcome.

Results

The proportion of women who adhered to hormone therapy was 76.3%. The likelihood of adherence to hormone therapy increased with each additional year of age, as well as among women with a secondary or higher level education, those with a partner, those who underwent surgery, those who had more consultations with a breast specialist and clinical oncologist, and those who underwent psychotherapy; the effect for the latter increased with each additional consultation. Conversely, the likelihood of adherence was lower among patients at a non-curable stage, those who were alcohol drinkers, those who received chemotherapy, those who had undergone more tests and had more hospitalizations, and those who used tamoxifen and combined aromatase inhibitors.

Conclusion

This study shows that approximately a quarter of the women with breast cancer did not adhere to hormone treatment, thus risking clinical responses below the expected standards. It also identifies the most vulnerable subgroups in the treatment process and the aspects of care that provide better results.