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

Social Characteristics and Adherence to Adjuvant Endocrine Therapy in Premenopausal Women With Breast Cancer

PURPOSESocial characteristics, including cohabitation/marital status and socioeconomic position (SEP)-education level, employment status, and income-influence breast cancer prognosis. We investigated the impact of these social characteristics on adherence to adjuvant endocrine therapy (AET) from treatment initiation to 5 years after diagnosis.METHODSWe assembled a nationwide, population-based cohort of premenopausal women diagnosed in Denmark with stage I-III, estrogen receptor-positive breast cancer during 2002-2011. We ascertained prediagnostic social characteristics from national registries. AET adherence was based on information from the Danish Breast Cancer Group and operationalized as (1) adherence trajectories (from group-based trajectory modeling) and (2) early discontinuation. We computed odds ratios (ORs) and associated 95% CI to estimate the association of cohabitation and SEP with AET adherence using multinomial and logistic regression models adjusted according to directed acyclic graphs.RESULTSAmong 4,353 patients, we identified three adherence trajectories-high adherence (57%), slow decline (36%), and rapid decline (6.9%). Compared with cohabiting women, those living alone had higher ORs of slow (1.26 [95% CI, 1.08 to 1.46]) or rapid decline (1.66 [95% CI, 1.27 to 2.18]) versus high adherence. The corresponding ORs for women not working versus employed women were 1.22 (95% CI, 1.02 to 1.45) and 1.76 (95% CI, 1.30 to 2.38). For early discontinuation (17%), the ORs were 1.48 (95% CI, 1.23 to 1.78) for living alone and 1.44 (95% CI, 1.17 to 1.78) for women not working.CONCLUSIONAdherence to AET was lower among women living alone or unemployed than cohabiting or employed women, respectively. These women may benefit from support programs to enhance AET adherence.

Dose Deintensified 3-Day Photon, Proton, or Brachytherapy: A Nonrandomized Controlled Partial Breast Irradiation Trial

PURPOSE

The optimal approach for partial breast irradiation (PBI) is unknown. We investigated a novel de-intensified 3-fraction PBI regimen for photons, protons, and brachytherapy.

METHODS AND MATERIALS

A multicenter nonrandomized controlled trial with the primary outcome of adverse cosmesis at 3 years versus before PBI. Eligibility criteria were age ≥50 years treated with breast-conserving surgery for node-negative estrogen receptor-positive (ER+) invasive breast cancer or any ductal carcinoma in situ (DCIS) measuring ≤2.5 cm. Photon and proton PBI were prescribed 21.9 Gy (relative biological effectiveness) and brachytherapy 21 Gy in 3 fractions. Radiation therapy technique and adjuvant endocrine therapy were selected at physician and patient discretion.

RESULTS

Between June 17, 2015, and July 13, 2017, 161 eligible patients were treated with photons (56), protons (49), or brachytherapy (56). Median patient age was 66.8 years. One hundred twenty-six (78.3%) had invasive breast cancer (all ER+) and 35 (21.7%) had DCIS (88.6% ER+). Fifty-four percent of patients with invasive breast cancer and 25.8% of patients with ER+ DCIS initiated and adhered to the prescribed endocrine therapy. The proportion of patients with adverse cosmesis (by trained nurse assessment) was 14.5% at baseline and 2.3% at 3 years (difference, -12.2%; 95% CI, -100% to -6.4%). Adverse cosmesis at the last follow-up, with a median follow-up of 5 years, was 5.7% by nurse assessment, 5.6% by panel assessment of digital photographs, and 5.2% by patient self-report. There were no observed clinically meaningful changes in other patient-reported outcomes, and just 2 grade 2 or higher adverse events, both grade 2, in the brachytherapy cohort. Five-year local recurrence-free survival and progression-free survival were 98.0% and 95.5%, respectively. There were no local recurrences among 60 patients with invasive breast cancer and Ki67 ≤13.25%.

CONCLUSIONS

Deintensified 3-day PBI provided favorable disease control, tolerability, and cosmetic outcomes, meeting the prespecified criteria for acceptability. This approach is an attractive option for patients with small node-negative ER+ breast cancer and DCIS.

Factors Influencing Adherence to Adjuvant Endocrine Therapy After Breast Cancer Surgery

BACKGROUND

Women with newly diagnosed hormone receptor-positive breast cancer are offered adjuvant endocrine therapy (AET). Despite the survival benefits of the therapy, a significant proportion of breast cancer patients do not adhere to the anti-hormonal medication.

AIMS

The purpose of this study was to analyse demographic, social, psychological and treatment-related factors influencing whether women diagnosed with early-stage breast cancer were adherent to offered therapy.

MATERIALS AND METHODS

This was a long-term retrospective, medical record study, supplemented with a questionnaire, including 81 women. Data from the Swedish Prescribed Drug Register were used to examine adherence. The women were followed for 5 years of offered AET.

RESULTS

Out of 81 women, 67 (83%) were adherent (hade taken out 80% or more of the recommended dose), 10 (12%) were Partially Adherent and 4 (5%) never accepted AET. At baseline, the Never-Adherent group members were younger, more often considered themselves healthy and seemed much more satisfied with their lives. Baseline factors that positively affected adherence were satisfaction with the vocational situation (p = 0.023) and satisfaction with family life (p = 0.040). Cumulative musculoskeletal side effects were more frequently reported among women in the Adherent group than Partially Adherent women, after both 12 and 60 months (p = 0.018 and p = 0.011, respectively). There was also a significant difference in reported cumulative psychological side effects (p = 0.049) in disfavour of the Adherent group. Moreover, according to the questionnaire where the women retrospectively were asked which side effects, they experienced during the treatment period; sexual desire was significantly lower in the Adherent group (p = 0.0402) than in the Partially Adherent group.

CONCLUSION

It is important to consider a woman's life situation, to support those who otherwise would not be able to complete AET and to help all women relieve side effects during AET. It should be investigated why some women did not start the recommended therapy.

A survey of women diagnosed with breast cancer experiencing oncology treatment-induced hot flushes: identification of specific characteristics as predictors of hot flush occurrence, frequency, and severity

PURPOSE

More women diagnosed with breast cancer (BC) are living with oncology treatment-induced hot flushes (HFs). This Australian-based survey explores why some women experience more severe or ongoing HF and whether specific population characteristics are predictive of HF occurrence, frequency, and/or severity.

METHODS

A non-probabilistic anonymous survey distributed online (Register4) and two Australian hospitals collected demographic and clinical information. Eligibility was consenting Australian-based women, 18 years and over, with a primary BC diagnosis. Analysis included linear and logistic regression models.

RESULTS

A total of 324 survey responses were analyzed. Chemotherapy and hormone therapy were each associated with HF occurrence (aOR = 2.92, 95% CI [1.27, 6.70], p = 0.01; and aOR = 7.50, 95% CI [3.02, 18.62], p < 0.001) and in combination (aOR = 5.98, 95% CI [2.61, 13.69], p < 0.001). Increased self-reported anxiety at BC diagnosis was significantly associated with HF frequency and severity scores (aCO = 0.71, 95% CI [0.31, 1.12], p = 0.001; and aCO = 0.44, 95% CI [0.33, 0.55], p < 0.001). Postmenopausal women had significantly lower HF severity and frequency scores than premenopausal women (aCO = -0.93, 95% CI [-1.62, -0.25], p = 0.008; and aCO = -2.62, 95% CI [-5.14, -0.11], p = 0.041).

CONCLUSIONS

Women with BC receiving chemotherapy and/or hormone therapy and premenopausal or experiencing elevated anxiety and/or stress will likely experience more severe oncology treatment-related HFs.

IMPLICATIONS FOR CANCER SURVIVORS

HFs continue across the BC treatment trajectory with women >5-year survivorship still reporting life impacts, with premenopausal women at the time of BC diagnosis at higher risk of experiencing severe and more frequent oncology treatment-induced HFs than postmenopausal women. Women at high risk require information on methods to moderate HF potential life impacts and maintain treatment compliance.

Familial adversity: association with discontinuation of adjuvant hormone therapy and breast cancer prognosis

BACKGROUND

Many studies have examined patient-related factors affecting adjuvant hormone therapy adherence in patients with breast cancer. Our study aimed to examine associations of family-related factors with adjuvant hormone therapy discontinuation and breast cancer-specific mortality.

METHODS

By cross-linking 7 Swedish health registers, we performed a cohort study that included all patients with breast cancer who initiated adjuvant hormone therapy during 2006-2019 in Sweden (N = 10 701). A group-based multitrajectory model was used to identify familial adversity groups based on 3 dimensions: material deprivation, negative family dynamics, and loss or threat of loss. Cox proportional hazard models were used to investigate associations of familial adversity with hormone therapy discontinuation and breast cancer-specific mortality.

RESULTS

We identified 5 distinctive familial adversity groups among the cohort participants. Compared with women who had low familial adversity, higher risks to discontinue adjuvant hormone therapy were observed among women with material deprivation (hazard ratio [HR] = 1.31, 95% confidence interval [CI] = 1.20 to 1.43), negative family dynamics (HR = 1.16, 95% CI = 1.06 to 1.28), loss or threat of loss (HR = 1.15, 95% CI = 1.00 to 1.32), or high familial adversity (HR = 1.53, 95% CI = 1.40 to 1.68). Furthermore, women with material deprivation (HR = 1.37, 95% CI = 1.05 to 1.79), negative family dynamics (HR = 1.41, 95% CI = 1.01 to 1.97), or high adversity (HR = 1.67, 95% CI = 1.26 to 2.23) were at higher risk of dying from breast cancer.

CONCLUSION

Familial adversity is associated with a higher risk of adjuvant hormone therapy discontinuation and breast cancer-specific mortality. Family-related factors identified in our study may help identify high-risk patients for interventions to prevent treatment discontinuation and subsequently improve breast cancer outcomes.

Preexisting Diabetes and Breast Cancer Treatment Among Low-Income Women

IMPORTANCE

Diabetes is associated with poorer prognosis of patients with breast cancer. The association between diabetes and adjuvant therapies for breast cancer remains uncertain.

OBJECTIVE

To comprehensively examine the associations of preexisting diabetes with radiotherapy, chemotherapy, and endocrine therapy in low-income women with breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included women younger than 65 years diagnosed with nonmetastatic breast cancer from 2007 through 2015, followed up through 2016, continuously enrolled in Medicaid, and identified from the linked Missouri Cancer Registry and Medicaid claims data set. Data were analyzed from January 2022 to October 2023.

EXPOSURE

Preexisting diabetes.

MAIN OUTCOMES AND MEASURES

Logistic regression was used to estimate odds ratios (ORs) of utilization (yes/no), timely initiation (≤90 days postsurgery), and completion of radiotherapy and chemotherapy, as well as adherence (medication possession ratio ≥80%) and persistence (<90-consecutive day gap) of endocrine therapy in the first year of treatment for women with diabetes compared with women without diabetes. Analyses were adjusted for sociodemographic and tumor factors.

RESULTS

Among 3704 women undergoing definitive surgery, the mean (SD) age was 51.4 (8.6) years, 1038 (28.1%) were non-Hispanic Black, 2598 (70.1%) were non-Hispanic White, 765 (20.7%) had a diabetes history, 2369 (64.0%) received radiotherapy, 2237 (60.4%) had chemotherapy, and 2505 (67.6%) took endocrine therapy. Compared with women without diabetes, women with diabetes were less likely to utilize radiotherapy (OR, 0.67; 95% CI, 0.53-0.86), receive chemotherapy (OR, 0.67; 95% CI, 0.48-0.93), complete chemotherapy (OR, 0.71; 95% CI, 0.50-0.99), and be adherent to endocrine therapy (OR, 0.71; 95% CI, 0.56-0.91). There were no significant associations of diabetes with utilization (OR, 0.95; 95% CI, 0.71-1.28) and persistence (OR, 1.09; 95% CI, 0.88-1.36) of endocrine therapy, timely initiation of radiotherapy (OR, 1.09; 95% CI, 0.86-1.38) and chemotherapy (OR, 1.09; 95% CI, 0.77-1.55), or completion of radiotherapy (OR, 1.25; 95% CI, 0.91-1.71).

CONCLUSIONS AND RELEVANCE

In this cohort study, preexisting diabetes was associated with subpar adjuvant therapies for breast cancer among low-income women. Improving diabetes management during cancer treatment is particularly important for low-income women with breast cancer who may have been disproportionately affected by diabetes and are likely to experience disparities in cancer treatment and outcomes.

Follow-up Routines Matter for Adherence to Endocrine Therapy in the Adjuvant Setting of Breast Cancer

Background

Endocrine therapy (ET) adherence leads to increased survival in breast cancer (BC). How follow-up should be done to maximize adherence is not known.

Objectives

To assess adherence to ET, factors favouring adherence to ET and effects on survival in a population-based cohort of BC patients in western Sweden.

Design

This is a retrospective study.

Methods

We included 358 patients operated for oestrogen receptor-positive BC and recommended 5 years of ET, in Region Halland, Sweden, year 2015 to 2016. Demographical, clinical and pathological data and use of ET were retrieved from the electronic medical records. Patients were considered adherent if taking ET for 5 years or during the full extent of the follow-up, until termination of ET due to BC relapse or death and where renewals of prescriptions of ET covered ⩾80% of the ordinated dose. Two follow-up routines were employed, ie, routine A where patients were contacted annually by nurses and a more passive follow-up routine B where patients were only contacted by nurses at 2 years and 5 years following start of ET.

Results

Medication persistence for 4 years and more was good and similar between patients initiating aromatase inhibitor (AI) and tamoxifen (75.7% and 72.0%, respectively, P = .43). More patients initiating AIs changed ET due to side effects compared with patients initiating tamoxifen (24.3% vs 9.9%, respectively, P < .0001). Endocrine therapy adherence was better for follow-up routine B than for follow-up routine A (hazard ratio [HR] = 2.71 [1.44-5.09], P = .0027).

Conclusions

Adherence to ET in BC is high in Western Sweden. Less regular nurse-initiated contacts between BC patients and nursesled surprisingly to a better adherence than a more regular nurse-initiated contact.

Lung cancer, comorbidities, and medication: the infernal trio

Most patients with lung cancer are smokers and are of advanced age. They are therefore at high risk of having age- and lifestyle-related comorbidities. These comorbidities are subject to treatment or even polypharmacy. There is growing evidence of a link between lung cancer, comorbidities and medications. The relationships between these entities are complex. The presence of comorbidities and their treatments influence the time of cancer diagnosis, as well as the diagnostic and treatment strategy. On the other hand, cancer treatment may have an impact on the patient's comorbidities such as renal failure, pneumonitis or endocrinopathies. This review highlights how some comorbidities may have an impact on lung cancer presentation and may require treatment adjustments. Reciprocal influences between the treatment of comorbidities and anticancer therapy will also be discussed.

Effects of Reishimmune-S, a Fungal Immunomodulatory Peptide Supplement, on the Quality of Life and Circulating Natural Killer Cell Profiles of Patients With Early Breast Cancer Receiving Adjuvant Endocrine Therapy

OBJECTIVES

To evaluate the effects of Reishimmune-S, a fungal immunomodulatory peptide, on the quality of life (QoL) and natural killer (NK) cell subpopulations in patients receiving adjuvant endocrine therapy (ET) for breast cancer (BC).

METHODS

Patients who received adjuvant ET for stage I-III hormone receptor-positive BC without active infection were enrolled in this prospective pilot study. Reishimmune-S was administered sublingually daily for 6 months. QoL scores, circulating immune cell levels, including lymphocyte/NK cell subpopulations, and plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α were measured at baseline and every 4 weeks. Data were analyzed using linear mixed-effect regression models.

RESULTS

Nineteen participants were included in the analyses. One patient with underlying asthma did not complete the study owing to the occurrence of skin rashes 15 days after the initiation of Reishimmune-S. No other adverse events were reported. Reishimmune-S supplementation significantly improved the cognitive function at 3 months and significantly decreased the fatigue and insomnia levels at 3 and 6 months, respectively. There was no significant change in the global health/QoL score between baseline and week 4 of treatment. The proportion of CD19+ lymphocytes was significantly higher at 3 and 6 months, and that of NKG2A+ and NKp30+ NK cells was significantly lower at 6 months than at baseline. In addition, fatigue positively correlated with the proportion of NKp30+ NK cells (β ± standard error: 24.48 ± 8.75, P = .007 in the mixed-effect model).

CONCLUSIONS

Short-term supplementation with Reishimmune-S affected the circulating immune cell composition and exerted positive effects on cognitive function, fatigue, and insomnia in patients with BC undergoing adjuvant ET, providing a potential approach for the management of treatment-related adverse reactions in this patient population.

Optimal adjuvant therapy in older (≥70 years of age) women with low-risk early-stage breast cancer

Older women are under-represented in breast cancer (BC) clinical trials, and treatment guidelines are primarily based on BC studies in younger women. Studies uniformly report an increased incidence of local relapse with omission of breast radiation therapy. Review of the available literature suggests very low rates of distant relapse in women ≥70 years of age. The incremental benefit of endocrine therapy in decreasing rate of distant relapse and improving disease-free survival in older patients with low-risk BC remains unclear. Integration of molecular genomic assays in diagnosis and treatment of estrogen receptor positive BC presents an opportunity for optimizing risk-tailored adjuvant therapies in ways that may permit treatment de-escalation among older women with early-stage BC. The prevailing knowledge gap and lack of risk-specific adjuvant therapy guidelines suggests a compelling need for prospective trials to inform selection of optimal adjuvant therapy, including omission of adjuvant endocrine therapy in older women with low risk BC.

Feasibility of Symptom Monitoring During the First Year of Endocrine Therapy for Early Breast Cancer Using Patient-Reported Outcomes Collected via Smartphone App

PURPOSE

Treatment-associated symptoms drive early discontinuation of adjuvant endocrine therapy (ET) for breast cancer. We hypothesized that symptom monitoring with electronic patient-reported outcomes (ePROs) during adjuvant ET will enhance symptom detection, symptom management, and persistence.

METHODS

Eligible patients were initiating ET for stage 0-III breast cancer. Participants completed ePRO surveys via smartphone at baseline and 1, 3, 6, and 12 months. Measures included Patient-Reported Outcomes Measurement Information System Anxiety, Depression, Fatigue, and Vaginal Discomfort; plus Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events items assessing joint pain, hot flashes, vaginal dryness, concentration problems, and memory problems. Scores surpassing prespecified thresholds triggered alerts, and recommended symptom management pathways were provided to clinicians. The primary objective was to evaluate feasibility, assessed by survey completion rates, with targets of >65% for the baseline survey and ≥1 follow-up survey during the first 6 months. Secondary objectives included 12-month ET discontinuation rate (target: ≤15%), describing symptoms and evaluating pathway implementation.

RESULTS

Among 250 participants, 73.2% completed the baseline survey and 69.6% completed ≥1 follow-up survey during the first 6 months. Thirty-one percent of participants had ≥1 symptom alert at baseline and 74% had ≥1 symptom alert during follow-up. The proportions of participants for whom pathway-concordant symptom management was documented at each time point ranged from 12.8% to 36.6%. Twenty-eight participants (11.2%) discontinued ET by 12 months.

CONCLUSION

Symptom monitoring with ePROs during adjuvant ET is feasible. Despite infrequent documentation of pathway-concordant symptom management after symptom alerts, ePROs were associated with favorable short-term ET persistence.

Adherence to and persistence with adjuvant hormone therapy, healthcare utilization, and healthcare costs among older women with breast cancer: A population-based longitudinal cohort study

INTRODUCTION

To assess associations between adherence to and persistence with adjuvant hormone therapy, healthcare utilization, and healthcare costs among older women with breast cancer.

MATERIALS AND METHODS

This study was a population-based longitudinal cohort study using the Surveillance, Epidemiology, and End Results (SEER) registry linked with Medicare claims. This study included older women diagnosed with stage I-III hormone receptor-positive breast cancer from 2009 through 2017. Participants were considered adherent with a proportion of days covered (PDC) of 0.80 or more and persistent if they had no hormone therapy discontinuation, i.e., a break of at least 180 continuous days. Length of persistence was calculated as time from therapy initiation to discontinuation. All participants were followed for up to five years after hormone therapy initiation. Generalized linear mixed models with repeated measures or hurdle generalized linear mixed models in the event of excess zeroes were used to assess associations between adherence to and persistence with annual healthcare utilization and costs.

RESULTS

This study included 25,796 women. Being adherent was associated with lower annual healthcare utilization, i.e., hospitalizations, hospital days, emergency room visits, and hospital outpatient visits. Persistence was associated with fewer annual hospitalizations, hospital days, emergency room visits, and hospital outpatient visits. Adherent participants had lower annual inpatient costs, outpatient costs, medical costs, and total healthcare costs despite higher prescription drug costs. Both being persistent and longer persistence were associated with lower inpatient costs, outpatient costs, medical costs, and total healthcare costs despite higher prescription drug costs.

DISCUSSION

This study underscores the economic benefits associated with adherence to and persistence with adjuvant hormone therapy based on comprehensive measures for healthcare utilization and costs. To our best knowledge, this was the first study that reported total healthcare cost savings associated with adherence to and persistence with adjuvant hormone therapy.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Concomitant Discontinuation of Cardiovascular Therapy and Adjuvant Hormone Therapy Among Patients With Breast Cancer

Importance

A large proportion of patients with breast cancer concomitantly use adjuvant hormone therapy and cardiovascular therapy.

Objective

To examine the relative risk of discontinuing cardiovascular therapy during the periods before and after discontinuation of adjuvant hormone therapy.

Design, Setting, and Participants

This population-based cohort study included all women aged 40 to 74 years in Stockholm, Sweden, who were diagnosed with breast cancer and concomitantly using adjuvant hormone therapy and cardiovascular therapy. Patients were enrolled from July 1, 2005, to August 31, 2020, with a median follow-up of 7.2 years. Data were analyzed from November 3, 2021, to May 12, 2022.

Exposure

Discontinuation of adjuvant hormone therapy.

Main Outcomes and Measures

The main outcome was discontinuation of cardiovascular therapy (cardiovascular drugs, statins, or aspirin) within 1 year before and after discontinuation of adjuvant hormone therapy. Incidence rate ratios with 95% CIs were estimated using Poisson regression. Furthermore, hazard ratios (HRs) with 95% CIs for cause-specific mortality were estimated using Cox proportional hazards regression models, comparing those who discontinued and continued adjuvant hormone therapy.

Results

A total of 5493 patients with breast cancer who concomitantly used cardiovascular therapy were identified; 1811 who discontinued adjuvant hormone therapy were individually matched to 1 patient each who continued therapy by year of breast cancer diagnosis, age at diagnosis, and use of the same cardiovascular therapy. Most patients (4070 [74.1%]) were aged 60 years or older at diagnosis. At the time when patients discontinued adjuvant hormone therapy, 248 (12.2%) concomitantly discontinued their cardiovascular therapy. During follow-up, a higher discontinuation rate of cardiovascular therapy was also observed among those who discontinued adjuvant hormone therapy. Consistently, adjuvant hormone therapy discontinuation was associated with an increased risk of death not only due to breast cancer (HR, 1.43; 95 CI%, 1.01-2.01) but also cardiovascular disease (HR, 1.79; 95 CI%, 1.15-2.81). Stratifying the analyses on baseline type of adjuvant hormone therapy yielded consistent results.

Conclusions and Relevance

In this cohort study of data from population-based registers in Sweden, patients who discontinued adjuvant hormone therapy were also more likely to discontinue cardiovascular therapy, especially at the time when they discontinued adjuvant hormone therapy. These findings suggest that clinicians should shift from single- to multiple-disease focus to prevent discontinuation of therapies for other diseases among patients with breast cancer.

Long-term outcomes of intraoperatively-placed applicator brachytherapy for rapid completion of breast conserving treatment: An analysis of a prospective registry data

Background and purpose

To evaluate the long-term outcome of accelerated partial breast irradiation utilizing intraoperatively placed applicator-based brachytherapy (ABB) in early-stage breast cancer.

Materials and methods

From our prospective registry, 223 patients with pTis-T2, pN0/pN1mic breast cancer were treated with ABB. The median treatment duration including surgery and ABB was 7 days. The prescribed doses were 32 Gy/8 fx BID (n = 25), 34 Gy/10 fx BID (n = 99), and 21 Gy/3 fx QD (n = 99). Endocrine therapy (ET) adherence was defined as completion of planned ET or ≥ 80% of the follow-up (FU) period. Cumulative incidence of ipsilateral breast tumor recurrence (IBTR) was estimated and influencing factors for IBTR-free survival rate (IBTRFS) were analyzed.

Results

218/223 patients had hormone receptor-positive tumors, including 38 (17.0%) with Tis and 185 (83.0%) with invasive cancer. After a median FU of 63 months, 19 (8.5%) patients had recurrence [17 (7.6%) with an IBTR]. Rates of 5-year IBTRFS and DFS were 92.2% and 91.1%, respectively. The 5-year IBTRFS rates were significantly higher for post-menopausal women (93.6% vs. 66.4%, p = 0.04), BMI < 30 kg/m2 (97.4% vs. 88.1%, p = 0.02), and ET-adherence (97.5% vs. 88.6%, p = 0.02). IBTRFS did not differ with dose regimens.

Conclusions

Postmenopausal status, BMI < 30 kg/m2, and ET- adherence predicted favorable IBTRFS. Our results highlight the importance of careful patient selection for ABB and encouragement of ET compliance.

Survival benefits associated with being adherent and having longer persistence to adjuvant hormone therapy across up to five years among U.S. Medicare population with breast cancer

PURPOSE

To assess associations between adherence to and persistence with adjuvant hormone therapy and mortality among older women with breast cancer.

METHODS

The surveillance, epidemiology, and end results data linked with U.S. Medicare claims was used. This study included older women diagnosed with stage I-III hormone receptor-positive breast cancer from 2009 through 2017. Adherence was defined as having proportion of days covered (PDC) ≥ 0.80. Persistence was defined as having no discontinuation, i.e., no break of ≥ 180 continuous days. Length of persistence was calculated as time from therapy initiation to discontinuation. Cox models with time-dependent covariates were used to assess associations between adherence and persistence with mortality.

RESULTS

This study included 25,796 women. Adherence rates were 78.1 percent, 75.2 percent, 72.4 percent, 70.0 percent, and 61.5 percent from year 1 to year 5 after hormone therapy initiation. Persistence rates were 87.5 percent, 81.7 percent, 77.1 percent, 72.9 percent, and 68.9 percent through cumulative intervals of 1 year up to 5 years. Adherence was associated with all-cause mortality but not associated with breast cancer-specific mortality. Persistent women had lower risk of all-cause mortality and breast cancer-specific mortality. Each additional year of persistence had additional contributions to survival benefits (11% decreased risk of all-cause mortality and 37% decreased risk of breast cancer-specific mortality).

CONCLUSION

This study confirms the detrimental effect of nonadherence to adjuvant hormone therapy across up to 5 years on all-cause survival in older U.S. women. It also reveals the survival benefits associated with having longer persistence across up to 5 years.

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.

Adherence to adjuvant tamoxifen and associated factors in breast cancer survivors

PURPOSE

Adjuvant endocrine therapy reduces the recurrence and mortality of early hormone receptor-positive breast cancer in both pre- and postmenopausal women. The aim of this study was to investigate adjuvant tamoxifen adherence and associated factors in breast cancer survivors.

METHODS

This descriptive, prospective study was conducted in 2019-2020 with the participation of 531 women who survived breast cancer and were under follow-up at the Senology Institute of a hospital in Istanbul. Inclusion criteria were having completed treatment for early hormone receptor-positive breast cancer, being prescribed tamoxifen, and being 18 years or older. Data were collected using a patient information form and the Morisky Medication Adherence Scale-8 (MMAS-8).

RESULTS

The mean age of the participants was 44.9 ± 6.5 years, and the mean duration of tamoxifen use was 834.4 ± 685.7 days. The women's mean MMAS-8 score was 6.86 ± 1.39. Medication adherence was significantly positively correlated with current age (p = 0.006) and age at diagnosis (p = 0.002). There was a statistically significant difference between tamoxifen adherence according to participants' employment status (p = 0.028), chronic disease status (p = 0.018), loss of libido (p = 0.012), treatment-related changes in mood changes (p = 0.004), and having negative effects affecting daily life (p < 0.001).

CONCLUSION

Overall, breast cancer survivors in this study reported moderate adherence to tamoxifen. The women's individual characteristics and the adverse effects of treatment influenced medication adherence. Healthcare professionals can help increase adherence to this treatment, which reduces the risk of mortality, by explaining the importance of the medication, identifying and eliminating barriers to adherence, and informing women about evidence-based interventions to increase medication compliance.

Adherence to endocrine therapy in early breast cancer in relation to Cytochrome P450 2D6 genotype: a comparison between pharmacy dispensation data and medical records

PURPOSE

Suboptimal adherence to adjuvant endocrine treatment (AET) is an important clinical concern. A correlation between CYP2D6 activity and tamoxifen discontinuation has been described. The main aim of this study was to investigate the consistency between pharmacy dispensation data and medical records on adherence to AET.

METHODS

Adherence was calculated for patients with at least 4.5 years of follow up and was defined as Medical Possession Rate ≥ 80%. Subgroup analyses were performed based on menopausal status, recurrence risk and CYP2D6 activity.

RESULTS

In 86% of the 1235 included patients the consistency between the two sources of information was within 80-125%. Poor consistency, < 80%, was most frequent in the premenopausal/ high-risk group and CYP2D6 Poor Metabolizers (PMs). Among 899 patients with at least 4.5 years follow up, 72% were adherent to tamoxifen based on pharmacy dispensation data, compared with 77% as reported by medical records. When including patients who switched to aromatase inhibitors after tamoxifen, adherence increased to 82% and 88%, respectively. Adherence did not differ by menopausal status or risk for recurrence. CYP2D6 PMs had poorer adherence (54%) to tamoxifen compared to patients with the highest CYP2D6 activity (83%).

CONCLUSIONS

There was a good consistency between medical records and pharmacy dispensing data on the use of AET. Adherence to AET was adequate, especially when including switch to aromatase inhibitors. Surprisingly, CYP2D6 PMs had low adherence to tamoxifen, despite a likely reduced risk of side effects according to previous data.

Adherence to oral anticancer hormonal therapy in breast cancer patients and its relationship with treatment satisfaction: an important insight from a developing country

BACKGROUND

Hormone-positive breast cancer is the most common type and represents a burden in all countries. Treatment satisfaction might be a predictor for adherence, as higher satisfaction with medication encourages patients to adhere appropriately to the medication and, consequently, successfully achieve the treatment goals. The present study evaluated the adherence of women with hormone-positive breast cancer to oral hormonal drugs and correlated it with treatment satisfaction and other sociodemographic and clinical factors.

METHODS

A cross-sectional design was applied. This study included two cancer centers. Data were collected from patients through face-to-face interviews and medical record reviews. The Medication Adherence Scale was adapted to assess medication adherence, and the Treatment Satisfaction Questionnaire for Medication (TSQM) version 1.4 was adopted to measure treatment satisfaction.

RESULTS

The final analysis included 106 patients, with a mean age ± SD of 51.9 ± 1.2. Approximately 35% were hospitalized in the past year. Current hormonal therapy among cancer patients included letrozole (38.7%), tamoxifen (31.1%), exemestane (17%), and anastrozole (13.2%). The median adherence score was 5.0 [4.8-6.0], and 62.3% adhered fully to their oral hormonal drugs in the past week. The median scores of effectiveness, side effects, convenience, and global satisfaction were 66.67 [61.11.0-72.22], 75.00 [48.44-100.00], 66.67 [66.67-72.22], and 71.43 [57.14-78.57], respectively. A significantly lower adherence score was identified in patients living in camps (p = 0.020). Patients with comorbidities and those who continued on the same hormonal therapy had higher adherence scores, although they were not statistically significant. Multiple linear regression analysis showed that two domains of treatment satisfaction, side effects (p = 0.013) and global satisfaction (p = 0.018), were predictors of adherence to oral hormonal drugs.

CONCLUSIONS

The current study revealed a significant association between treatment satisfaction and adherence to oral hormonal therapy. We recommend creating a specialized scale to measure adherence, considering the psychosocial factors that affect hormonal anticancer medication adherence.

Side Effects and Its Management in Adjuvant Endocrine Therapy for Breast Cancer: A Matter of Communication and Counseling

Objective

Women with a newly diagnosed hormone receptor-positive breast cancer are offered adjuvant endocrine therapy (AET). Although the treatment reduces the risk of relapse and death not all women are adherent to it. Many factors, including the therapy's menopausal side effects, can adversely affect adherence to the treatment. This study explores the extent to which women treated with AET perceived that health care providers addressed their side effects.

Methods

Ten focus groups were set up, containing between four to nine women. In total, 58 women participated in the study-45 from the Stockholm metropolitan region and 13 from the scarcely populated Norrbotten region. The interviews were analyzed using qualitative content analysis with an inductive approach.

Results

The women were usually satisfied with the care they received from the health care providers. However, their experiences were more complex when it came to their satisfaction with the care in terms of the menopausal side effects of therapy, sexuality in particular. The participants reported that their healthcare providers rarely asked about sex life-related side effects of the treatment.

Conclusions

Health care providers need to communicate and consult about issues related to their patients' sex lives following their breast cancer diagnosis and during their treatment.

Effects of tamoxifen on normal breast tissue histological composition: Results from a randomised six-arm placebo-controlled trial in healthy women

Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to "no dose" (0-1 mg), "low-dose" (2.5-5 mg) or "high-dose" (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.

Adjuvant radiation therapy for older women with early-stage breast cancer: a propensity-matched SEER analysis

INTRODUCTION

The purpose was to evaluate the effect of adjuvant radiation therapy on the survival prognosis of older women with early-stage breast cancer under different surgical treatments.

METHODS

We collected patients from the Surveillance, Epidemiology and End Results (SEER) database. Elderly female patients (≥ 70 years) with stage I-IIB diagnosed with invasive carcinoma in 1988-2017 were included. After propensity score matching (PSM), the prognosis of patients who underwent breast-conserving surgery or mastectomy was calculated separately. The effects of radiotherapy on the survival of three special population groups (breast-conserving surgery + T1N0M0 + ER positive, mastectomy + T3N0M0 and mastectomy + T1-2N1M0) were analyzed selectively.

RESULTS

Of 106,553 older women with early-stage breast cancer were identified. 48,630 patients had received radiotherapy, while 57,923 patients had not. After PSM, older women undergoing breast-conserving surgery benefited significantly from radiotherapy (both OS and BCSS p < 0.001), for patients with T1N0M0 and ER-positive breast cancer (both OS and BCSS p < 0.001). In the subgroup of T1-2N1M0 breast cancer treated by mastectomy, patients undergoing radiotherapy had a worse survival as well (OS p < 0.001; BCSS p = 0.0907). While in the subgroup of T3N0M0 breast cancer treated by mastectomy, survival analyses showed no statistical differences between patients receiving radiation or not (OS p = 0.1778, BCSS p = 0.6957).

CONCLUSIONS

This study indicated the clinical effects of radiation on older women who received different surgical treatments. Our study suggested that radiotherapy should be omitted in older women undergoing mastectomy + T3N0M0 or T1-2N1M0 and radiotherapy could be considered in women with T1N0M0 + ER-positive undergoing breast-conserving surgery.

Radiation in Early-Stage Breast Cancer: Moving beyond an All or Nothing Approach

Radiotherapy omission is increasingly considered for selected patients with early-stage breast cancer. However, with emerging data on the safety and efficacy of radiotherapy de-escalation with partial breast irradiation and accelerated treatment regimens for low-risk breast cancer, it is necessary to move beyond an all-or-nothing approach. Here, we review existing data for radiotherapy omission, including the use of age, tumor subtype, and multigene profiling assays for selecting low-risk patients for whom omission is a reasonable strategy. We review data for de-escalated radiotherapy, including partial breast irradiation and acceleration of treatment time, emphasizing these regimens' decreasing biological and financial toxicities. Lastly, we review evidence of omission of endocrine therapy. We emphasize ongoing research to define patient selection, treatment delivery, and toxicity outcomes for de-escalated adjuvant therapies better and highlight future directions.

Factors associated with initiation and continuation of endocrine therapy in women with hormone receptor-positive breast cancer

Background

Despite benefits of endocrine therapy (ET) for patients with hormone-receptor (HR)-positive breast cancer, many patients do not initiate or discontinue ET against recommendations.

Methods

We identified variables associated with ET initiation and continuation, analyzing pooled data from two longitudinal studies at a National Cancer Institute comprehensive cancer center in St. Louis, Missouri. The sample included 533 women with newly diagnosed, non-metastatic, HR-positive breast cancer who completed interviews at enrollment and 6, 12, and 24 months after definitive surgical treatment. Logistic regression models estimated the adjusted odds ratio and 95% confidence interval (aOR [95% CI]) for each of self-reported ET initiation by the 12-month interview and continuation for ≥12 months by the 24-month interview in association with self-reported diabetes, elevated depressed mood, menopausal-symptom severity and obesity, adjusting for race, age, insurance status, chemotherapy, and radiation therapy.

Results

Overall, 81.4% (434/533) of patients initiated ET, and 86.5% (371/429) continued ET ≥12 months. Patients with diabetes had lower odds of initiating ET (0.50 [0.27-0.91]). Patients reporting greater menopausal-symptom severity had lower odds of continuing ET (0.72 [0.53-0.99]).

Conclusion

Efforts to increase ET initiation among patients with diabetes and better manage severe menopausal symptoms among ET users might promote ET continuation.

Clinical trial information

ClinicalTrials.gov: #NCT00929084.

Determinants and Effectiveness of Extending the Duration of Adjuvant Hormone Therapy beyond 5 Years in Patients with Breast Cancer

Clinical guidelines have recommended patients with high-risk breast cancer to extend adjuvant hormone therapy beyond 5 years. However, the prevalence, predictors, and outcomes of extended adjuvant hormone therapy in the real world remain unknown. By linking six Swedish health registries, we prospectively followed 13,168 patients with breast cancer (2005-2020) from their first prescription of tamoxifen or aromatase inhibitors and categorized them as extending or not extending adjuvant hormone therapy. Cox regression analysis was used to investigate whether extended therapy was associated with breast cancer outcomes. Among patients with breast cancer who were recommended to extend adjuvant hormone therapy by the national guidelines, the proportion of women who extended therapy increased 5 folds during the past 10 years, reaching 80.9% during 2018 to 2020. Patients were more likely to extend therapy after completing 5-year adjuvant hormone therapy if they were young [40 vs. ≥65 years: OR, 1.71; 95% confidence interval (CI), 1.13-2.58], had positive lymph nodes (OR, 2.25; 95% CI, 1.85-2.73), had high tumor grade (grade 3 vs. 1: OR, 1.79; 95% CI, 1.34-2.39), received chemotherapy (OR, 5.22; 95% CI, 4.19-6.50), had first-degree relatives who died from breast cancer (OR, 1.84; 95% CI, 1.21-2.81), or had a high income (OR, 1.23; 95% CI, 1.01-1.49). Extended use of adjuvant hormone therapy was statistically significantly associated with improved disease-free survival (HR, 0.72; 95 CI%, 0.55-0.95). This study provides real-world evidence showing the use and improved breast cancer outcomes of extended adjuvant hormone therapy beyond 5 years.

SIGNIFICANCE

The proportion of patients with breast cancer extending adjuvant hormone therapy beyond 5 years has increased dramatically in recent years, which is associated with improved patient outcomes.

Persistence with tamoxifen and aromatase inhibitors in Germany: a retrospective cohort study with 284,383 patients

PURPOSE

The aim of this study was to analyze the persistence of women on tamoxifen (TAM) and aromatase inhibitors (AIs) in Germany, and to investigate possible determinants of non-persistence.

METHODS

The present retrospective cohort study was based on the IQVIA longitudinal prescription database (LRx). The study included women with an initial prescription of TAM or AIs (anastrozole, letrozole, and exemestane) between January 2016 and December 2020 (index date). Kaplan-Meier analyses were performed to show the persistence for TAM and AI, using a therapy gap of 90 or 180 days, respectively. A multivariable Cox proportional hazards regression model was further used to estimate the relationship between non-persistence and drug prescription (AI versus TAM), age, and the specialty of the physician initiating therapy (gynecologist, oncologist, or general practitioner).

RESULTS

Up to 5 years after the index date, only 35.1% of AI and 32.5% of TAM patients were continuing therapy when therapy discontinuation was defined as at least 90 days without therapy. Using a 180-day therapy gap, 51.9% of AI and 50.4% of TAM patients remained on therapy after 5 years. Cox regression models reveal that initial therapy with TAM (HR 1.06, 95% CI 1.04-1.07), therapy initiation by oncologists (HR 1.09, 95% CI 1.07-1.11), or general practitioners (HR 1.24, 95% CI 1.21-1.27) and age ≤ 50 (HR 1.08, 95% CI 1.06-1.10) were significantly associated with an increased risk of therapy discontinuation.

CONCLUSION

Overall, the present study indicates that persistence rates are low in all age groups for both TAM and AI treatment. We found several factors (e.g., physician specialty, younger age, and type of endocrine therapy) to be associated with an increased risk for non-persistence.

Adjuvant Hormone Therapy-Related Hot Flashes Predict Treatment Discontinuation and Worse Breast Cancer Prognosis

BACKGROUND

Clinical trials have shown that adjuvant hormone therapy (AHT)-related hot flashes can predict better breast cancer outcomes. This population-based cohort study investigated whether this result can be generalized to a real-world setting.

PATIENTS AND METHODS

By linking the National Quality Registry for Breast Cancer, Prescribed Drug Register, and Cause-of-Death Register, we identified 7,152 chemotherapy-free patients with breast cancer who initiated AHT in Stockholm from 2006 through 2019, and followed them until 2020. Hot flashes were defined as new use of drugs for hot flashes within 6 months after initiating AHT. We used Cox models to compare disease-free survival and treatment discontinuation among patients with and without hot flashes.

RESULTS

Patients who newly used drugs for hot flashes shortly after AHT initiation had worse disease-free survival (adjusted hazard ratio [HR], 1.67; 95% CI, 1.11-2.52) and a higher treatment discontinuation rate (adjusted HR, 1.47; 95% CI, 1.21-1.78). The association between drugs for hot flashes and discontinuation of AHT differed by patient characteristics, with stronger associations among low-income patients (HR, 1.91; 95% CI, 1.41-2.59) and those without first-degree relatives who had cancer (HR, 1.81; 95% CI, 1.39-2.35) or died from cancer (HR, 1.71; 95% CI, 1.37-2.12).

CONCLUSIONS

AHT-related hot flashes predict worse, rather than better, breast cancer outcomes among patients in clinical routine practice. The identification of adverse effects by the initiation of hot flash medications may identify a subset of patients with more severe hot flashes who are more likely to discontinue AHT and need more support for treatment adherence.

Factors influencing five-year adherence to adjuvant endocrine therapy in breast cancer patients: A systematic review

Purpose

This systematic review aimed to determine the rate and identify correlates of adherence and persistence over five years of treatment with adjuvant endocrine therapy in female breast cancer patients.

Methods

Relevant articles were identified from Medline, Embase, AMED, PsycINFO, International Pharmaceutical Abstracts, and APA PsycArticles. Studies that measured patient adherence in the implementation or persistence phase for a period of at least five years using objective or multiple measures of adherence and investigated correlates of adherence were included. The titles, abstracts and full articles were screened and reviewed by two authors and any discrepancies were discussed with a third author.

Results

Twenty-six studies were included. Mean rate of adherence at five-year for implementation phase was 66.2% (SD = 17.3%), and mean persistence was 66.8% (SD = 14.5%). On average, adherence decreased by 25.5% (SD = 9.3%) from the first to fifth year. Higher rate of adherence was observed through self-report in comparison to database or medical record. Older age, younger age, higher comorbidity index, depression and adverse effects were associated with lower adherence. Treatment with aromatase inhibitors, received chemotherapy, and prior medication use were associated with improved adherence.

Conclusion

Adherence to adjuvant endocrine therapy decreased from the first to fifth year of treatment. On average, one-third of patients were not adherent to treatment by the fifth year. Nineteen recurring factors were found to be significantly associated with long-term adherence in multiple studies. Further research using objective or multiple measures of adherence are needed to improve validity of results.

•

On average, adherence fell by 25.5% from the first to the fifth year of treatment.

•

Self-reported adherence may overestimate patient adherence.

•

Nineteen recurring factors were associated with adherence.

•

Having adverse effects was negatively associated with adherence.

Association of Adjuvant Hormone Therapy Timing With Overall Survival Among Patients With Hormone Receptor-Positive Human Epidermal Growth Factor Receptor-2-Negative Early Breast Cancer Without Chemotherapy

Importance

Studies have shown that delayed initiation of surgery and adjuvant chemotherapy is associated with lower rates of breast cancer survival. However, it remains unclear whether delayed initiation of adjuvant hormone therapy (AHT) is associated with survival.

Objective

To assess the association of time to adjuvant hormone therapy (TTH) with breast cancer survival and evaluate the factors associated with AHT.

Design, Setting, and Participants

This cohort study examined data from the National Cancer Database from 2004 through 2014 to assess the association of TTH (stratified as ≤150 and >150 days) with cancer survival. All patients included were diagnosed with stage I to stage III hormone receptor-positive, human epidermal growth factor receptor-2 (ERBB2; formerly HER2)-negative invasive breast cancer and underwent AHT without chemotherapy. Data were analyzed from April 2019 to May 2020.

Exposures

AHT was administered at different time points following surgical procedures for breast cancer treatment.

Main Outcomes and Measures

An inverse probability of treatment weighting (IPTW) model was constructed to evaluate overall survival by adjusting for treatment facility, patient demographics, tumor characteristics, and treatment; multivariable logistic regression was conducted to assess factors associated with delayed treatment.

Results

A total of 144 103 patients (median [IQR] follow-up, 36.6 months [25.5-49.2 months]; mean [SD] age, 63.7 [11.6] years) were identified, which included 142 916 (99.2%) women, 11 574 (8.0%) Black patients, and 126 013 (87.4%) White patients. Of these, 134 873 patients (93.6%) had a TTH of 150 days or less and 9230 patients (6.4%) had a TTH longer than 150 days. The IPTW-based Cox model demonstrated that patients with delayed AHT (ie, a TTH past 150 days) were associated with decreased survival (hazard ratio [HR], 1.31; 95% CI, 1.26-1.35; P < .001) compared with those receiving the timely treatment (TTH ≤150 days). Several sensitivity analyses (including IPTW with stabilized weight [HR, 1.31; 95% CI, 1.19-1.45; P < .001], propensity score matching [HR, 1.41; 1.13-1.76; P = .002], and propensity score regression adjustment [HR, 1.29; 95% CI, 1.16-1.43; P < .001]) and exploratory subgroup analyses yielded similar trends. Factors associated with delayed AHT included Black racial identity (OR, 1.66; 95% CI, 1.55-1.77), nonprivate insurance (eg, no insurance: OR, 1.46; 95% CI, 1.26-1.70), living in large metropolitan or metropolitan areas (reference vs urban, less urban, or rural: OR, 0.82; 95% CI, 0.76-0.87), treatment in a community hospital (reference vs academic or research: OR, 0.91; 95% CI, 0.84-0.98), Charlson-Deyo Comorbidity Index score 2 or higher (OR, 1.17; 95% CI, 1.04-1.32), poor grade differentiation (OR, 1.42; 95% CI, 1.32-1.53), II and III pathological stage (stage III: OR, 3.13; 95% CI, 2.76-3.54), estrogen receptor-positive (ER+)/progesterone receptor-negative (PR-) or ER-/PR+ (OR, 1.22; 95% CI, 1.13-1.31), receiving breast conservation surgery (reference vs mastectomy: OR, 0.87; 95% CI, 0.79-0.94), and radiotherapy (reference vs no radiotherapy: OR, 0.56; 95% CI, 0.52-0.61).

Conclusions and Relevance

The delay of the initiation of AHT past 150 days was associated with diminished survival in hormone receptor-positive, ERBB2-negative patients with breast cancer who did not receive chemotherapy. Efforts should be made to address factors associated with delayed treatment to improve survival.

Preliminary results using a kit to measure tamoxifen and metabolites concentrations in capillary blood samples from women with breast cancer

The aim of the study was to compare 3 blood sampling methods, including capillary blood sampling, for determining Tamoxifen (TAM), Z-endoxifen (END), and 4-hydroxytamoxifen (4HT) concentrations. High performance liquid chromatography-mass spectrometry was used to quantify concentrations of TAM, END, and 4HT in plasma, venous blood, and capillary blood samples of 16 participants on TAM therapy for breast cancer. The rhelise kit was used for capillary sampling. Calibration curves using ¹³C-labeled analogs of TAM, END, and 4HT as internal standards were used for quantifications. A capillary sampling kit was used successfully for all participants. Mean TAM concentrations did not differ significantly in the 3 types of samples. Mean END and 4HT concentrations did differ significantly between capillary and venous blood samples, possibly related to photodegradation in the internal standards prior to use or degradation products with chromatographic retention times similar to the metabolites. TAM, END, and 4HT concentrations were relatively stable when stored for 14 days at 8 °C and 20 °C. Therapeutic drug monitoring of TAM using an innovative kit and capillary blood sampling is feasible. Preliminary data from this study will aid in developing a multicenter, randomized clinical trial of personalized TAM dose monitoring and adjustments, with the goal of enhancing the quality-of-life and outcomes of patients with breast cancer.

Clinical Trial Identification: EudraCT No 2017-000641-44.

Patient preferences and adherence to adjuvant GnRH analogs among premenopausal women with hormone receptor positive breast cancer

PURPOSE

Adjuvant ovarian function suppression (OFS) in premenopausal hormone receptor (HR) positive breast cancer (BC) improves survival. Adherence to adjuvant gonadotropin-releasing hormone analogs (GnRHa) remains a challenge and is associated with toxicities and inconvenient parenteral administration. The goal of this study was to describe real-world adherence patterns and patient preferences surrounding adjuvant GnRHa.

METHODS

We analyzed the medical records of premenopausal women with non-metastatic HR positive BC from January 2000 to December 2017; participants received adjuvant monthly goserelin or leuprolide at The Ohio State University. Data collected included demographics, clinicopathologic characteristics, and OFS adherence/side effects. We defined non-adherence as discontinuation of GnRHa within 3 years for a reason other than switching to an alternate OFS, delay > 7 days from a dose, or a missed dose. Chi-square tests assessed associations between clinical characteristics and outcomes.

RESULTS

A total of 325 patients met eligibility. Of these, 119 (37%) patients were non-adherent to GnRHa; 137 (42%) underwent elective bilateral salpingo-oophorectomy after initial GnRHa. Those opting for surgery reported significantly more hot flashes (74% vs 48%, p < 0.001), arthralgias (46% vs 30%, p = 0.003), and vaginal dryness (37% vs 21%, p = 0.001) compared with patients remaining on GnRHa.

CONCLUSION

Non-adherence to adjuvant GnRHa occurred in over a third of patients and almost half the patients initiating GnRHa underwent subsequent surgical ablation. These high frequencies highlight real-world patterns of OFS. Additionally, treatment toxicities may impact personal preference of OFS modality. Personalized practices to target predictors of adjuvant GnRHa non-adherence are critical to optimize symptoms, adherence, and survivorship.

Impact of systemic adjuvant therapy and CYP2D6 activity on mammographic density in a cohort of tamoxifen-treated breast cancer patients

PURPOSE

Change in mammographic density has been suggested to be a proxy of tamoxifen response. We investigated the effect of additional adjuvant systemic therapy and CYP2D6 activity on MD change in a cohort of tamoxifen-treated pre- and postmenopausal breast cancer patients.

METHODS

Swedish breast cancer patients (n = 699)  operated 2006-2014, genotyped for CYP2D6, having at least three months postoperative tamoxifen treatment, a baseline, and at least one follow-up digital mammogram were included in the study. Other systemic adjuvant treatment included chemotherapy, goserelin, and aromatase inhibitors. Change in MD, dense area, was assessed using the automated STRATUS method. Patients were stratified on baseline characteristics, treatments, and CYP2D6 activity (poor, intermediate, extensive, and ultrarapid). Relative density change was calculated at year 1, 2, and 5 during follow-up in relation to treatments and CYP2D6 activity.

RESULTS

Mean relative DA decreased under the follow-up period, with a more pronounced MD reduction in premenopausal patients. No significant effect of chemotherapy, aromatase inhibitors, goserelin, or CYP2D6 activity on DA change was found. DA did not revert to baseline levels after tamoxifen discontinuation.

CONCLUSION

Our results indicate that other systemic adjuvant therapy does not further reduce MD in tamoxifen-treated breast cancer patients. We could not confirm the previously suggested association between CYP2D6 activity and MD reduction in a clinical setting with multimodality adjuvant treatment. No rebound effect on MD decline after tamoxifen discontinuation was evident.

Bone Mineral Density at the Time of Initiating Aromatase Inhibitor Therapy Is Associated With Decreased Fractures in Women With Breast Cancer

Women with estrogen receptor-positive breast cancer who receive an aromatase inhibitor (AI) are at risk for fractures. We aim to determine if dual-energy X-ray absorptiometry (DXA) scans made at the time of AI initiation are associated with decreased fractures. We retrospectively identified 25,158 women with local or regional breast cancer diagnosed between 2005 and 2013 who received AI therapy between 2007 and 2013 from the Medicare-linked Surveillance, Epidemiology, and End Results Program and Texas Cancer Registry databases. We defined baseline DXA screening using claims made between 1 year before and 6 months after each patient's first AI claim to examine determinants of baseline screening using a multivariable GENMOD model. We included a propensity score adjustment in Cox proportional hazard models to assess the association between time-varying DXA screening and the risk of fractures. Additionally, we compared the use of antiresorptive therapy drugs between the two groups. Of the study cohort, 14,738 (58.6%) received DXA screening. The screening rates increased annually from 52.1% in 2007 to 61.7% in 2013. Higher screening rates were observed in patients with younger age, married status, non-Hispanic white race, localized disease, fewer comorbidities, more than one type of aromatase inhibitor drug claim, no state buy-in (surrogate for low socioeconomic status), higher education level, and prior osteoporosis diagnosis. Baseline DXA screening was associated with decreased risk of subsequent fractures (hazard ratio = 0.91; 95% confidence interval, 0.86-0.97, p < .001) after multivariable and propensity score adjustment. Bone-modifying drugs were prescribed to 4440 (30.1%) patients with screening compared with 1766 (16.9%) without (p < .001). Of the 4440 patients who received treatment, 95% received bisphosphonates. Our study demonstrated baseline DXA screening was associated with a decreased risk of fractures and a higher likelihood of receiving antiresorptive therapies. Improvement of the baseline DXA screening is still needed in practice. © 2021 American Society for Bone and Mineral Research (ASBMR).

Low-Dose Tamoxifen for Mammographic Density Reduction: A Randomized Controlled Trial

Tamoxifen prevents breast cancer in high-risk women and reduces mortality in the adjuvant setting. Mammographic density change is a proxy for tamoxifen therapy response. We tested whether lower doses of tamoxifen were noninferior to reduce mammographic density and associated with fewer symptoms.

Adaptation of the Charlson Comorbidity Index for Register-Based Research in Sweden

Purpose

Comorbidity indices are often used to measure comorbidities in register-based research. We aimed to adapt the Charlson comorbidity index (CCI) to a Swedish setting.

Methods

Four versions of the CCI were compared and evaluated by disease-specific experts.

Results

We created a cohesive coding system for CCI to 1) harmonize the content between different international classification of disease codes (ICD-7,8,9,10), 2) delete incorrect codes, 3) enhance the distinction between mild, moderate or severe disease (and between diabetes with and without end-organ damage), 4) minimize duplication of codes, and 5) briefly explain the meaning of individual codes in writing.

Conclusion

This work may provide an integrated and efficient coding algorithm for CCI to be used in medical register-based research in Sweden.

Assessing Predictors of Tamoxifen Nonadherence in Patients with Early Breast Cancer

Adjuvant endocrine therapy (AET) is generally proposed to all patients with hormone receptor-positive breast cancer to reduce the risk of recurrence and death. Adherence to therapy is crucial. However, non-adherence to AET is common, with estimates of up to 50% of patients not successfully completing a five-year course of treatment, and it is significantly associated with lower survival rates and a higher risk of recurrence. Currently, no gold standard is available to assess adherence. Several studies, most of them retrospective in nature, have used both direct and indirect methods to monitor the adherence to therapy in breast cancer. The indirect method is more widely used, and it is based on pharmacy prescription refills and patient administered questionnaires. On the other hand, direct methods such as a measurement of the level of the drug or its metabolites in blood or urine are much more precise, but more expensive and not routinely implemented. In this review, we analyzed the results of the major studies focused on the adherence to tamoxifen in breast cancer patients. We identified several factors associated with poor adherence, such as the side effects of therapy, the lack of shared decision-making between the physician and patient, the context in which the discussion takes place, and whether the patients are enrolled in a clinical trial. Moreover, we discussed possible methods to improve adherence to adjuvant therapy in breast cancer.

Treatment interruption and discontinuation of hormonal therapy in hormone receptor-positive breast cancer patients

PURPOSE

To investigate predictors of treatment interruption and early discontinuation of adjuvant hormonal therapy (HT) in a retrospective cohort of women with newly diagnosed hormone receptor-positive (HR +) breast cancer.

METHODS

Eligible cases were identified from a single institutional tumor registry from 2009 to 2015. Patients were followed from initiation of adjuvant HT for a minimum of one year through December 1, 2016. Predictors of treatment interruption or early discontinuation were analyzed with Cox proportional hazards regression models.

RESULTS

With a median follow-up time of 3.0 years (IQR 1.5-4.5), 22 women (10.9%) discontinued HT early and 47 (23.4%) had at least one treatment interruption of > 14 days. Adjusted Cox proportional hazards regression models showed that women with pre-existing affective disorders were more likely to discontinue therapy early (HR 3.15; 95% CI 1.35-7.37), while those with pre-existing chronic pain disorders were at increased risk for treatment interruption (HR 2.24; 95% CI 1.20-4.19). HT-related symptoms were the most commonly reported reason for HT interruption or discontinuation. Women who experienced severe treatment-related symptoms were at increased risk for both HT interruption (HR 2.64; 95% CI 1.07-6.50) and HT discontinuation (HR 3.48; 95% CI 1.20-10.1).

CONCLUSIONS

This study showed that HT interruptions and discontinuation were common, often associated with HT-related symptoms. Clinicians caring for breast cancer patients on HT should monitor closely for treatment-emergent symptoms, especially women with pre-existing disorders, and support them to continue therapy through aggressive symptom management and other patient-centered approaches.

Adjuvant radiation therapy alone is associated with improved overall survival compared to hormonal therapy alone in older women with estrogen receptor positive early stage breast cancer

Background

Breast conserving surgery (BCS) and adjuvant hormonal therapy (HT) without radiation therapy (RT) is an acceptable approach for older women with early stage, estrogen receptor (ER) positive breast cancer. Toxicity and compliance remain issues with HT. Adjuvant RT alone may have better compliance, but its efficacy in the absence of HT is unclear. We aim to assess patterns of adjuvant therapy and survival outcomes among older women with early stage, ER positive (ER+) breast cancer.

Methods

The National Cancer Data Base (NCDB) was used to identify 130,194 women age ≥65 years with invasive ER+, node negative breast cancer diagnosed between 2004 and 2015. All patients underwent BCS. Kaplan‐Meier survival curves were used to examine overall survival (OS). The association between adjuvant therapy and OS was assessed in multivariable Cox proportional hazards regression models.

Results

Unadjusted 5/10‐year OS rates were 90.0%/64.3% for HT and RT, 84.2%/54.9% for RT alone, 78.7%/44.5% for HT alone, and 71.6%/38.0% for no treatment; p<0.001 for all. Compared to HT alone, the 10‐year multivariable hazard ratio (HR) for death for RT alone was 0.86 (95% CI 0.82‐0.91). In propensity‐matched patients who received RT alone or HT alone (n=21,326), RT alone had significantly better survival at 5 (HR_adj: 0.84) and 10 (HR_adj: 0.87) years.

Conclusions

Older women with early stage ER+ breast cancer who undergo BCS and receive both HT and RT have the best survival, while RT as single‐modality therapy had higher rates of OS at 5 and 10 years compared to HT alone.

Predictors of increased risk for early treatment non-adherence to oral anti-estrogen therapies in early-stage breast cancer patients

PURPOSE

Non-adherence to the oral anti-estrogen therapies (AET) tamoxifen and aromatase inhibitors in early-stage hormone receptor-positive breast cancer is associated with numerous negative clinical outcomes. Prior studies have identified that non-adherence is associated with psychological and menopause-related factors which are present during AET, but the presence of these characteristics prior to AET initiation has not been investigated.

METHODS

Psychological and menopause symptoms (depression, generalized anxiety, insomnia, somatosensory amplification, hot flash frequency, and hot flash-related interference) were assessed pre-AET initiation as predictors of subsequent non-adherence in 73 participants (M_age = 55.0, SD = 10.1 years). Participants self-reported treatment adherence after three and 6 weeks on AET. Participants who did not initiate treatment were excluded from the analysis.

RESULTS

Discriminant function analyses revealed that the hypothesized set of psychological and menopause symptoms at baseline (pre-AET) together statistically distinguished between those who were non-adherent (n = 19; 26.0%) from adherent (n = 54; 74.0%) at 6 weeks. Model classification accuracy was statistically significant (Wilks' ƛ = 0.782, χ²(6) = 15.50, p = 0.017) at the 6-week timepoint. Results were consistent at 3 weeks. Pre-AET psychological and menopause symptoms correctly classified 6-week treatment adherence 77.9% of the time. Depression contributed most to distinguishing between adherers and non-adherers.

CONCLUSIONS

The presence of a composite profile of psychological and menopause symptoms prior to AET initiation may help to identify early treatment non-adherence. Results can be used to identify patients at risk for non-adherence and to guide psychological and symptom management interventions.

Patient interactive digital support for women with adjuvant endocrine therapy in order to increase compliance and quality of life

PURPOSE

The primary aim of the study was to develop and investigate a patient interactive digital support (an app) for patients on adjuvant endocrine breast cancer treatment. Patient's interactive digital applications are a fast-growing area for research and development. In general, patients want more information and support with regard to their diagnosis, treatment and self-care. At the same time, the health care system has limited resources for follow-up. Our primary endpoints were usability of the app and if it added any value to the patients.

METHODS

We designed and constructed a prototype, in dialogue with patients, containing four main modules for registration of drug compliance, performed physical exercise, self-care activities, and questions on health and quality of life. The app was then tested by patients and improved further before we completed a pilot study in which 15 patients used the app for 3 months.

RESULTS

Patients perceived the app easy to use with a very high median system usability score of 88.8, range 30-100. The 15 women registered in total 4251 times, range 118 to 372. The majority of registrations concerned compliance (adherence to treatment) and physical exercise.

CONCLUSION

The app was perceived easy to use and of support in every-day life of breast cancer survivors. How to best integrate electronically collected patient reported outcome measures in clinical routine needs to be further studied, and future research will show if it will be cost-effective in terms of better health outcome and less resource use.

Impact of ovarian function suppression in premenopausal women with estrogen receptor-positive early breast cancer

PURPOSE OF REVIEW

This manuscript aims at providing an updated overview on the role of adding ovarian function suppression to tamoxifen or an aromatase inhibitor as adjuvant endocrine therapy in premenopausal women with estrogen receptor-positive early breast cancer.

RECENT FINDINGS

Until recently, tamoxifen alone was the only recommended adjuvant treatment option for premenopausal women with estrogen receptor-positive disease. However, recent important evidence has contributed to significantly modify the endocrine treatment landscape in this setting.

SUMMARY

With the only exception of patients with low-risk clinical-pathological features characterized by excellent survival outcomes with tamoxifen alone, the use of ovarian function suppression is to be considered standard of care for most of premenopausal women with estrogen receptor-positive disease. Regarding the choice of its best partner as endocrine agent, the available data suggest that the higher the risk of disease recurrence the larger benefit can be observed with a more profound estrogen deprivation that can be obtained with ovarian function suppression and an aromatase inhibitor as compared to ovarian function suppression and tamoxifen. Despite the significant improvement in our understanding on the role of ovarian function suppression in this setting, several unanswered questions remain and further research efforts are needed in the field.

The therapy is making me sick: how online portal communications between breast cancer patients and physicians indicate medication discontinuation

Objective

Online platforms have created a variety of opportunities for breast patients to discuss their hormonal therapy, a long-term adjuvant treatment to reduce the chance of breast cancer occurrence and mortality. The goal of this investigation is to ascertain the extent to which the messages breast cancer patients communicated through an online portal can indicate their potential for discontinuing hormonal therapy.

Materials and Methods

We studied the de-identified electronic medical records of 1106 breast cancer patients who were prescribed hormonal therapy at Vanderbilt University Medical Center over a 12-year period. We designed a data-driven approach to investigate patients' patterns of messaging with healthcare providers, the topics they communicated, and the extent to which these messaging behaviors associate with the likelihood that a patient will discontinue a prescribed 5-year regimen of therapy.

Results

The results indicates that messaging rate over time [hazard ratio (HR) = 1.373, P = 0.002], mentions of side effects (HR = 1.214, P = 0.006), and surgery-related topics (HR = 1.170, P = 0.034) were associated with increased risk of early medication discontinuation. In contrast, seeking professional suggestions (HR = 0.766, P = 0.002), expressing gratitude to healthcare providers (HR = 0.872, P = 0.044), and mentions of drugs used to treat side effects (HR = 0.807, P = 0.013) were associated with decreased risk of medication discontinuation.

Discussion and Conclusion

This investigation suggests that patient-generated content can inform the study of health-related behaviors. Given that approximately 50% of breast cancer patients do not complete a course of hormonal therapy as described, the identification of factors associated with medication discontinuation can facilitate real-time interventions to prevent early discontinuation.

CYP2D6 Genotype Predicts Tamoxifen Discontinuation and Prognosis in Patients With Breast Cancer

PURPOSE

To examine the association between CYP2D6 genotype, discontinuation of tamoxifen therapy, and prognosis for breast cancer.

PATIENTS AND METHODS

We conducted a prospective-retrospective study linking data from a clinical breast cancer register, the Swedish Prescribed Drug Register, and self-reported questionnaires. We genotyped CYP2D6 in 1,309 patients with breast cancer who were treated with tamoxifen and were diagnosed from 2005 to 2012; they were categorized as poor, intermediate, normal, or ultrarapid CYP2D6 metabolizers. We investigated whether metabolizer status was associated with tamoxifen discontinuation and prognosis for breast cancer using Cox regression analysis.

RESULTS

The 6-month discontinuation rates of tamoxifen among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were 7.1%, 7.6%, 6.7%, and 18.8%, respectively. A U-shaped association was found between CYP2D6 metabolizer status and breast cancer–specific mortality, with adjusted hazard ratios of 2.59 (95% CI, 1.01 to 6.67) for poor, 1.48 (95% CI, 0.72 to 3.05) for intermediate, 1 (reference) for normal, and 4.52 (95% CI, 1.42 to 14.37) for ultrarapid CYP2D6 metabolizers.

CONCLUSION

Both poor and ultrarapid CYP2D6 metabolizers of tamoxifen have a worse prognosis for breast cancer compared with normal metabolizers after receiving a standard dose of tamoxifen. This U-shaped association might call for individualized tamoxifen dosage.

Aromatase inhibitors: The unexpected breast cancer treatment

OBJECTIVE

Suboptimal adherence with endocrine treatment for breast cancer is influenced by a number of factors but remains poorly understood. We sought to describe the prior knowledge about and expectations of breast cancer treatments among older women retrospecting on their diagnosis and treatment.

METHODS

Thematic analysis was used to systematically analyze data obtained with face-to-face, open-ended interviews conducted with 54 women who had filled at least one prescription for an aromatase inhibitor. The average age was 71.9 (65-93) years at diagnosis.

RESULTS

Three salient themes were described: the sources of information on which preknowledge and expectations surrounding treatment were founded, and two phases of treatment, primary (surgery, chemotherapy and radiation therapy) and anti-hormonal. The main source of information was from family and friends who had been treated for cancer. These peers reported both positive and negative experiences and in many cases contributed to the women having some degree of misinformation. A foundational knowledge of primary treatments was evident (necessity, duration, intensity, side-effects) and that receiving one or more treatments was needed. Compared to primary treatments, anti-hormonal treatment (AHT) was unexpected, the women knew less about it, and felt comparatively under-prepared for this treatment.

CONCLUSIONS

The transition from primary treatments to adjuvant AHT therapy with receiving a prescription for an aromatase inhibitor caught many participants off guard. Our findings elucidate areas to enhance clinical practice, expand the research agenda to more thoroughly explore AHT information and design of an age-appropriate supportive intervention to improve continuation with AHT.

A DREAM Challenge to Build Prediction Models for Short-Term Discontinuation of Docetaxel in Metastatic Castration-Resistant Prostate Cancer

Purpose

Docetaxel has a demonstrated survival benefit for patients with metastatic castration-resistant prostate cancer (mCRPC); however, 10% to 20% of patients discontinue docetaxel prematurely because of toxicity-induced adverse events, and the management of risk factors for toxicity remains a challenge.

Patients and Methods

The comparator arms of four phase III clinical trials in first-line mCRPC were collected, annotated, and compiled, with a total of 2,070 patients. Early discontinuation was defined as treatment stoppage within 3 months as a result of adverse treatment effects; 10% of patients discontinued treatment. We designed an open-data, crowd-sourced DREAM Challenge for developing models with which to predict early discontinuation of docetaxel treatment. Clinical features for all four trials and outcomes for three of the four trials were made publicly available, with the outcomes of the fourth trial held back for unbiased model evaluation. Challenge participants from around the world trained models and submitted their predictions. Area under the precision-recall curve was the primary metric used for performance assessment.

Results

In total, 34 separate teams submitted predictions. Seven models with statistically similar area under precision-recall curves (Bayes factor ≤ 3) outperformed all other models. A postchallenge analysis of risk prediction using these seven models revealed three patient subgroups: high risk, low risk, or discordant risk. Early discontinuation events were two times higher in the high-risk subgroup compared with the low-risk subgroup. Simulation studies demonstrated that use of patient discontinuation prediction models could reduce patient enrollment in clinical trials without the loss of statistical power.

Conclusion

This work represents a successful collaboration between 34 international teams that leveraged open clinical trial data. Our results demonstrate that routinely collected clinical features can be used to identify patients with mCRPC who are likely to discontinue treatment because of adverse events and establishes a robust benchmark with implications for clinical trial design.

Adherence and Persistence to Adjuvant Hormonal Therapy in Early-Stage Breast Cancer Patients: A Population-Based Retrospective Cohort Study in Israel

Background

Adjuvant hormonal therapy (HT) has been consistently proven to improve multiple outcomes in early breast cancer yet rates of adherence and persistence are variable.

Methods

We retrospectively identified women diagnosed with nonmetastatic breast cancer and initiating HT between January 2000 and December 2007 in a large Israeli health provider. Prescription records including the drug name, date of purchase, and the quantity of pills dispensed were collected. We used Cox proportional hazards and binary logistic models to analyze factors associated with early discontinuation (<5 years) and nonadherence (proportion of days covered, PDC <80%) of HT, respectively.

Results

A total of 4,178 women with breast cancer were identified with nearly 95% of patients treated with tamoxifen as the initial HT. Over the 5-year follow-up period, early discontinuation was identified in 955 (23%) patients. The mean PDC was 82.9% (SD 0.004). Younger age and low BMI were both associated with an increased risk of early discontinuation and nonadherence. A history of hypertension was associated with a higher likelihood of both outcomes.

Conclusion

Adherence and persistence with HT among Israeli breast cancer survivors are comparable to those in international reports. Interventions are necessary to identify and prevent suboptimal HT adherence.

Adherence to Adjuvant Endocrine Therapy in Insured Black and White Breast Cancer Survivors: Exploring Adherence Measures in Patient Data

BACKGROUND

Adjuvant endocrine therapy (AET) is a critical therapy in that it improves survival in women with hormone receptor-positive (HR+) breast cancer (BC), but adherence to AET is suboptimal. The purpose of this study was to fill scientific gaps about predictors of adherence to AET among black and white women diagnosed with BC.

OBJECTIVE

To assess AET adherence in black and white insured women using multiple measures, including one that uses an innovative statistical approach.

METHODS

Black and white women newly diagnosed with HR+ BC were identified from 2 health maintenance organizations. Pharmacy records captured the type of oral AET prescriptions and all fill dates. Multivariable logistic regression was used to identify predictors of adherence defined in terms of proportion of days covered (PDC; ≥ 80%) and medication gap of ≤ 10 days. A zero-inflated negative binomial (ZINB) regression model was used to identify variables associated with the total number of days of medication gaps.

RESULTS

1,925 women met inclusion criteria. 80% were PDC adherent (> 80%); 44% had a medication gap of ≤ 10 days; and 24% had no medication gap days. Race and age were significant in all multivariable models. Black women were less likely to be adherent based on PDC than white women (OR = 0.72, 95% CI = 0.57-0.90, P < 0.01), and they were less likely to have a medication gap of ≤ 10 days (OR = 0.65, 95% CI = 0.54-0.79, P < 0.001). Women aged 25-49 years were less likely to be PDC adherent than women aged 65-93 years (OR = 0.65, 95% CI = 0.48-0.87, P < 0.001). In the ZINB model, women were without their medication for an average of 37 days (SD = 50.5).

CONCLUSIONS

Racial disparities in adherence to AET in the study highlight a need for interventions among insured women. Using various measures of adherence may help better understand this multidimensional concept. There might be benefits from using both more common dichotomous measures (e.g., PDC) and integrating novel statistical approaches to allow tailoring adherence to patterns within a specific sample.

DISCLOSURES

This research was funded by the National Institutes of Health (R01CA154848). It was also supported in part by the NIH-NCI Cancer Center Support Grant P30 CA016059, the Laboratory of Telomere Health P30 CA51008, and the TSA Award No. UL1TR002649 from the National Center for Advancing Translational Sciences. The contents of this study are solely the responsibility of the authors and do not necessarily represent official views of the National Center for Advancing Translational Sciences or the National Institutes of Health. Bosworth reports grants from Sanofi, Otsuka, Johnson & Johnson, and Blue Cross/Blue Shield of NC and consulting fees from Sanofi and Otsuka. The other authors have nothing to disclose. The datasets generated during and/or analyzed during the current study are not publicly available due to privacy reasons but are available from the corresponding author on reasonable request. The author does not own these data. Data use was granted to the author as part of a data use agreement between specific agencies and organizations.