Use of tamoxifen and aromatase inhibitors in a large population-based cohort of women with breast cancer. Br J Cancer. 2011;104:1558-1563. [PMID: 21522148 PMCID: PMC3101914 DOI: 10.1038/bjc.2011.140]

Identification of non-adherence to adjuvant letrozole using a population pharmacokinetics approach in hormone receptor-positive breast cancer patients

BACKGROUND

Letrozole, an aromatase inhibitor metabolised via CYP2A6 and CYP3A4/5 enzymes, is used as adjuvant therapy for women with hormone receptor (HR)-positive early breast cancer. The objective of this study was to quantify the impact of CYP2A6 genotype on letrozole pharmacokinetics (PK), to identify non-adherent patients using a population approach and explore the possibility of a relationship between non-adherence and early relapse.

METHODS

Breast cancer patients enrolled in the prospective PHACS study (ClinicalTrials.gov NCT01127295) and treated with adjuvant letrozole 2.5 mg/day were included. Trough letrozole concentrations (Css,trough) were measured every 6 months for 3 years by a validated LC-MS/MS method. Concentration-time data were analysed using non-linear mixed effects modelling. Three methods were evaluated for identification of non-adherent subjects using the base PK model.

RESULTS

617 patients contributing 2534 plasma concentrations were included and led to a one-compartment PK model with linear absorption and elimination. Model-based methods identified 28 % of patients as non-adherent based on high fluctuations of their Css,trough compared to 3 % based on patient declarations. The covariate analysis performed in adherent subjects revealed that CYP2A6 intermediate (IM) and slow metabolisers (SM) had 21 % (CI95 % = 12 - 30 %) and 46 % (CI95 % = 41 - 51 %) lower apparent clearance, respectively, compared to normal and ultrarapid metabolisers (NM+UM). Early relapse (19 patients) was not associated with model-estimated, concentration-based or declared adherence in the total population (p = 0.41, p = 0.37 and p = 0.45, respectively).

CONCLUSIONS

These findings will help future investigations focusing on the exposure-efficacy relationship for letrozole in adjuvant setting.

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.

Compliance to adjuvant endocrine therapy and survival in breast cancer patients

BACKGROUND

Data on compliance to adjuvant endocrine treatment (ET) is mainly reported from prospective clinical trials or from smaller retrospective cohorts without correlation to outcome.

AIMS

To determine compliance to adjuvant ET and the impact on survival in a population-based series of patients with early breast cancer (BC) advised ET.

PATIENTS AND METHODS

1090 consecutive patients with hormone receptor positive (HR+) stage I-III BC diagnosed from 1 January 1997 to 31 December 2003 from one health care region of Sweden were included. Data on tumour, type of ET, compliance, reason for termination and outcome were collected. Statistical analyses were calculated with patients in three groups.

RESULTS

72 patients were excluded leaving 1018 patients with a HR+ stage I to III BC for analyses. The most common ET was tamoxifen (n = 751, 73.8%). At the last follow up (31 Dec 2019) with a median follow-up of 18 years (interquartile range 16-22) 228 (22.4%) patients had a relapse. 71.1% of the included patients were compliant to endocrine therapy. Older patients ≥74 years had lower compliance, 61% compared with 75% in the other age groups (≤50 years and 51-73 years) (p < 0001), other parameters including type of ET were not associated with compliance. Low compliance remained as an independent risk factor in multivariate analyses for lower relapse-free survival, HR=1.83, 95% Confidence Interval (CI) 1.52-2.19, p < 0.001 and for time to BC death, HR=2.69, 95%CI 1.82-3.98, p < 0.001.

CONCLUSIONS

Patients compliant to adjuvant ET have an improved survival.

Analysing breast cancer survivors’ acceptance profiles for using an electronic pillbox connected to a smartphone application using Seintinelles, a French community-based research tool

Introduction: Up to 50% of breast cancer (BC) survivors discontinue their adjuvant endocrine therapy (AET) before the recommended 5 years, raising the issue of medication non-adherence. eHealth technologies have the potential to support patients to enhance their medication adherence and may offer an effective way to complement the healthcare. In order for eHealth technologies to be successfully implemented into the healthcare system, end-users need to be willing and accepting to use these eHealth technologies.

Aim: This study aims to evaluate the current usability of eHealth technologiesin and to identify differences in BC SURVIVORS BC survivors accepting a medication adherence enhancing eHealth technology to support their AET to BC survivors that do not accept such a medication adherence enhancing eHealth technology.

Methods: This study was conducted in 2020 including volunteering BC survivors belonging to the Seintinelles Association. Eligible participants were women, diagnosed with BC within the last 10 years, and been exposed to, an AET. Univariable and multivariable logistic regression analyses were performed to investigate medication adherence enhancing eHealth technology acceptance profiles among BC survivors. The dependent variable was defined as acceptance of an electronic pillbox connected to a smartphone application (hereafter: medication adherence enhancing eHealth technology).

Results: Overall, 23% of the participants already use a connected device or health application on a regular basis. The mean age of the participants was 52.7 (SD 10.4) years. In total, 67% of 1268 BC survivors who participated in the survey declared that they would accept a medication adherence enhancing eHealth technology to improve their AET. BC survivors accepting a medication adherence enhancing eHealth technology for their AET, are younger (OR = 0.97, 95% CI [0.95; 0.98]), do take medication for other diseases (OR = 0.31, 95% CI [0.13; 0.68]), already use a medication adherence enhancing eHealth technology or technique (OR = 1.74, 95% CI [1.06; 2.94]) and are willing to possess or currently possess one or more connected devices or health applications (OR = 2.89, 95% CI [2.01; 4.19]).

Conclusion: Understanding acceptance profiles of BC survivors is fundamental for conceiving an effective eHealth technology enhancing AET among BC survivors. Hence, such profiling will foster the development of personalized medication adherence enhancing eHealth technology.

Assessment of compliance with hormonal therapy in early breast cancer patients with positive hormone receptor phenotype: A single institution study

Background

Adherence to long-term adjuvant hormonal therapy in hormonal receptors (HR)-positive breast cancer is really challenging and can affect the survival outcome. The present study aims to assess rate of compliance with hormonal therapy and possible predictive factors in a single institute in Saudi Arabia.

Patients &methods

We recruited patients with HR-positive breast cancer who presented to oncology outpatient clinics. Patients were assessed for compliance using a study questionnaire. Compliance was defined as taking ≥80% of prescribed doses of oral hormonal therapy. Different epidemiological, clinical, pathological and treatment data were checked in patients’ medical records and correlated with compliance/interruption of hormonal therapy.

Results

Among the 203 recruited patients, 95.1% were compliant with hormonal therapy, while it was interrupted in 16.7% of patients, and 58.1% reported missing intake of hormonal pills. Age >50 years, having permanent job and higher education level were significantly associated with non-compliance in univariate analysis. On multivariate analysis, job status was the only independent predictor of non-compliance. The following parameters were significantly related to hormonal therapy interruption: marital status (single: 28.8% vs married patients: 12.6%, p = 0.01) and residence location (Makkah: 11.7% vs. outside Makkah: 25.3%, p = 0.019), lymphovascular invasion (LVI) (No: 20.9%, Yes: 7.8%, p = 0.025) and N0 tumours (compared to node-positive patients, p = 0.008). On multivariate analysis, marital status, residence location and N-stage, maintained significance relation with hormonal therapy interruption.

Conclusion

Compliance with hormonal therapy was high in the study cohort. Marital status, residence location, job status and N-stage may be related to interruption/compliance with hormonal therapy.

•

Compliance rate to adjuvant hormonal therapy was high in Saudi patients.

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Job status was significantly associated to hormonal therapy compliance.

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Marital status, residence location and N0-stage were linked with hormonal therapy interruption.

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Side effects were related to hormonal therapy interruption in a minority of patients.

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.

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

•

Self-reported adherence may overestimate patient adherence.

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Nineteen recurring factors were associated with adherence.

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Having adverse effects was negatively associated with adherence.

Metformin as a new option in the medical management of breast fibroadenoma; a randomized clinical trial

BACKGROUND

Fibroadenoma (FA) is the most common benign solid breast mass in women, with no definite method of management. Because fibroadenoma is dependent on female sex hormones and comprises hypertrophic changes at cellular levels, we investigated the effects of metformin (MF), a safe hypoglycemic agent with anti-estrogenic and anti-proliferative properties, in the management of fibroadenoma.

METHODS

In this randomized clinical trial study, eligible women with fibroadenomas were assigned randomly to the metformin (1000 mg daily for six months) or the placebo group. Breast physical and ultrasound exam was performed before and after the intervention, and the changes in the size of fibroadenomas were compared in the two groups.

RESULTS

Overall, 83 patients in the treatment, and 92 in the placebo group completed the study. A statistically significant difference in changing size between the two groups was observed only in the smallest mass. In the largest FAs, the rate of size reduction was higher in the treatment group (60.2 % vs. 43.5 %); while a higher rate of enlargement was observed in the placebo group (38 % vs. 20.5 %). In the smallest FAs, the rate of the masses that got smaller or remained stable was about 90 % in the treatment group and 50 % in the placebo group. We categorized size changes of FAs into < 20 % enlargement and ≥ 20 % enlargement. The odds ratio (OR) for an elargemnt less than 20% was 1.48 (95 % CI = 1.10-1.99) in the treatment group in comparison with the placebo group; the odds for an enlargement less than 20% was higher in women with multiples fibroadenomas (OR = 4.67, 95 % CI: 1.34-16.28). In our study, no serious adverse effect was recorded, and the medicine was well-tolerated by all users.

CONCLUSIONS

This is the first study that evaluates the effect of MF on the management of fibroadenoma, and the results suggest a favorable effect. Larger studies using higher doses of MF and including a separate design for patients with single or multiple FAs are suggested in order to confirm this effect.

TRIAL REGISTRATION

This trial (IRCT20100706004329N7) was retrospectively registered on 2018-10-07.

Early Discontinuation of Endocrine Therapy and Recurrence of Breast Cancer among Premenopausal Women

PURPOSE

Premenopausal women diagnosed with estrogen receptor (ER)-positive breast cancer are prescribed 5-10 years of endocrine therapy to prevent or delay recurrence. In this study, we evaluated the association between early discontinuation of endocrine therapy and breast cancer recurrence in a cohort of premenopausal women.

EXPERIMENTAL DESIGN

We identified 4,503 patients with premenopausal ER-positive breast cancer who initiated adjuvant endocrine therapy and were registered in the Danish Breast Cancer Group clinical database (2002-2011). Women were excluded if they had a recurrence or were lost to follow-up less than 1.5 years after breast cancer surgery. Endocrine therapy was considered complete if the patient received at least 4.5 years of treatment or discontinued medication less than 6 months before recurrence. Exposure status was updated annually and modeled as a time-dependent variable. We accounted for baseline and time-varying confounders via time-varying weights, which we calculated from multivariable logistic regression models, and included in regression models to estimate HRs and 95% confidence intervals (CIs) associating early discontinuation with recurrence.

RESULTS

Over the study follow-up, 1,001 (22%) women discontinued endocrine therapy. We observed 202 (20%) recurrences among those who discontinued endocrine therapy, and 388 (11%) among those who completed the recommended treatment. The multivariable-adjusted estimated rate of recurrence was higher in women who discontinued endocrine therapy relative to those who completed their treatment (hazard ratio, 1.67; 95% CI, 1.25-2.14).

CONCLUSIONS

These results highlight the importance of clinical follow-up and behavioral interventions that support persistence of adjuvant endocrine therapy to prevent breast cancer recurrence.

Cardiotoxicity of Use of Sequential Aromatase Inhibitors in Women With Breast Cancer

The association between use of aromatase inhibitors (AIs) and cardiovascular outcomes is controversial. While some observational studies have assessed the cardiovascular safety of AIs as upfront treatments, their cardiotoxicity as sequential treatments with tamoxifen remains unknown. Thus, we conducted a population-based cohort study using data from the United Kingdom Clinical Practice Research Datalink linked to the Hospital Episode Statistics and Office for National Statistics databases. We employed a prevalent new-user design to propensity-score match, in a 1:2 ratio, patients switching from tamoxifen to AIs with patients continuing tamoxifen between 1998 and 2016. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the study outcomes (myocardial infarction, ischemic stroke, heart failure, and cardiovascular mortality). Overall, 1,962 patients switching to AIs were matched to 3,874 patients continuing tamoxifen. Compared with tamoxifen, AIs were associated with an increased risk of myocardial infarction (hazard ratio (HR) = 2.08, 95% confidence interval (CI): 1.02, 4.27). The hazard ratios were elevated for ischemic stroke (HR = 1.58, 95% CI: 0.85, 2.93) and heart failure (HR = 1.69, 95% CI: 0.79, 3.62) but not cardiovascular mortality (HR = 0.87, 95% CI: 0.49, 1.54), with confidence intervals including the null value. The elevated hazard ratios observed for the cardiovascular outcomes should be corroborated in future large observational studies.

First prospective outcome data for the second-generation multigene test Endopredict in ER-positive/HER2-negative breast cancer

Purpose

Prospectively collected outcome data of patients (pts) whose adjuvant systemic therapy recommendation was based on the clinico-molecular test EndoPredict^® (EP) are presented.

Methods

Pts with ER-positive, HER2-negative early breast cancer with 0–3 positive lymph nodes were enrolled. The EP was carried out on all tumor samples. Pts were evaluated for treatment compliance, local recurrence, distant metastases and overall survival. Censored time-to-event outcomes were analysed by Cox proportional hazards models. Additional estimates of the event-free-survival were calculated by the Kaplan–Meier method. Hypothesis testing was conducted on two-sided exploratory 5% significance levels.

Results

373 consecutive pts were enrolled. EP classified 238 pts (63.8%) as low risk and 135 pts (36.2%) as high risk. Median follow-up was 41.6 months. Risk for disease recurrence or death in EPclin high-risk patients was twofold higher in comparison with EPclin low-risk patients (hazard ratio (HR) 2.05 (95% CI 0.85–4.96; p = 0.110). Patients with EPclin high risk were at significant higher risk of distant metastases than patients with EPclin low risk (HR 5.18; 95% CI 1.04–25.74; p = 0.0443). EPclin high-risk patients who actually underwent adjuvant CTX had a 3-year-DFS of 96.3% (95% CI 92.2–100) in contrast to EPclin high-risk patients without CTX (3-year-DFS: 91.5% (95% CI 82.7–100%); HR 0.32; 95% CI 0.10–1.05; p = 0.061).

Conclusion

These first prospective outcome results show that EP, in clinical routine, is a valid clinico-molecular test, to predict DFS and to guide decision of adjuvant CTX use in ER-positive, HER2-negative early breast cancer pts with 0–3 positive lymph nodes. Adjuvant CTX seems to be beneficial for EPclin high-risk patients.

Factors influencing adherence to adjuvant endocrine therapy in breast cancer-treated women: using real-world data to inform a switch from acute to chronic disease management

PURPOSE

Adjuvant endocrine therapy (AET) for ≥ 5 years is generally recommended for women with hormone receptor-positive breast cancer to reduce cancer recurrence/mortality; however, adherence can be suboptimal. We tested determinants of AET adherence using patient characteristics, treatment pathways, AET initiation timing, and multiple healthcare facility use. An underlying objective was to explore how oncological pathways mirror chronic disease management to monitor adherence and target improvement interventions using administrative datasets.

METHODS

Using patient-linked administrative health data from the Italian Lombardy Region, we identified 33.291 surviving patients starting AET in 2010-2016, with two (22.939 patients) or five years (8400 patients) follow-up, using a ≥ 80% prescription refill approach to measure adherence and logistic regression to test determinants of adherence.

RESULTS

AET crude adherence falls significantly during follow-up, from 94% at 1 Year to 58% at 5 Years. At 5 Years, patients who were older (>70), prescribed tamoxifen-only (OR 0.69; 95% CI 0.57-0.83; p = 0.0001) vs. aromatase inhibitors-only or therapy switches, treated for depression (OR 0.68; 95% CI 0.60-0.78; p < 0.0001), with surgery performed in high-volume hospitals (OR 0.85; 95% CI 0.75-0.97; p = 0.0116) showed lower adherence. Loyalty, or continued care in the surgical hospital (OR 1.73; 95% CI 1.51-2.00; p < 0.0001), undergoing chemotherapy before AET (OR 2.65; 95% CI 2.02-3.48; p < 0.0001), and earlier AET initiation, positively influenced adherence.

CONCLUSIONS

Chronic disease monitoring using administrative data can help oncologists focus efforts to ensure AET adherence. Results suggest addressing mental health, age, disease severity patient perceptions, timely AET initiation and therapy switches, and encouraging continued follow-up in the same hospital or better care coordination with outside follow-up specialists.

BCL9/STAT3 regulation of transcriptional enhancer networks promote DCIS progression

The molecular processes by which some human ductal carcinoma in situ (DCIS) lesions advance to the more aggressive form, while others remain indolent, are largely unknown. Experiments utilizing a patient-derived (PDX) DCIS Mouse INtraDuctal (MIND) animal model combined with ChIP-exo and RNA sequencing revealed that the formation of protein complexes between B Cell Lymphoma-9 (BCL9), phosphoserine 727 STAT3 (PS-727-STAT3) and non-STAT3 transcription factors on chromatin enhancers lead to subsequent transcription of key drivers of DCIS malignancy. Downregulation of two such targets, integrin β3 and its associated metalloproteinase, MMP16, resulted in a significant inhibition of DCIS invasive progression. Finally, in vivo targeting of BCL9, using rosemary extract, resulted in significant inhibition of DCIS malignancy in both cell line and PDX DCIS MIND animal models. As such, our studies provide compelling evidence for future testing of rosemary extract as a chemopreventive agent in breast cancer.

Outcomes of primary endocrine therapy in elderly women with stage I-III breast cancer: a SEER database analysis

BACKGROUND

Frail elderly women with nonmetastatic hormone receptor-positive breast cancer often receive primary endocrine therapy. Limited data are available on the outcomes associated with this population and treatment approach.

METHODS

We selected patients with an initial primary diagnosis of stage I-III ER-positive breast cancer from 2001 to 2015 in Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Patients were excluded if they received surgery, radiation, chemotherapy, or other targeted drug treatment including anti-HER2 agents. Two Cox proportional-hazards models were constructed to determine the predictors of breast cancer-specific survival and overall survival after a cancer diagnosis.

RESULTS

A total of 552 patients were identified, with 82.1% of the patients being 80 years or older and 81.7% of patients being non-Hispanic White. PR positive (OR 1.77; 95% CI 1.09-2.85; p = 0.025) and tumor size larger than 50 mm (OR 1.99; 95% CI 1.05-3.75; p = 0.035) were associated with higher adherence to endocrine therapy. In the multivariable Cox analyses, patients who were adherent of endocrine therapy had significantly worse survival (HR 1.40; 95% CI 1.17-1.69; p < 0.001). The other two factors associated with worse survival were larger tumor size and more comorbidities. The competing risk model demonstrated no statistically significant difference between patients who were adherent to endocrine therapy and those who were not in terms of risk of dying from breast cancer.

CONCLUSION

In elderly women with localized ER-positive breast cancer, there were no statistically significant differences in breast cancer-specific or overall mortality between those who were adherent to endocrine therapy and those who were not.

Factors associated with endocrine therapy adherence among post-menopausal women treated for early-stage breast cancer in Ontario, Canada

PURPOSE

Adherence to adjuvant endocrine therapy among post-menopausal breast cancer patients is an important survivorship care issue. We explored factors associated with endocrine therapy adherence and survival in a large real-world population-based study.

METHODS

We used health administrative databases to follow women (aged ≥ 66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2010. Adherence was measured by medical possession ratio (MPR) and characterized as low (< 39% MPR), intermediate (40-79% MPR), or high (≥ 80% MPR) over a 5-year period. We investigated factors associated with adherence using a multinomial logistic regression model. Factors associated with all-cause mortality (5 years after starting endocrine therapy) were investigated using a multivariable Cox proportional hazards model.

RESULTS

We identified 5692 eligible patients starting adjuvant endocrine therapy who had low, intermediate, and high adherence rates of 13% (n = 749), 13% (n = 733), and 74% (n = 4210), respectively. Lower rates of adherence were associated with increased age [low vs. high adherence: odds ratio (OR) 1.03, 95% CI 1.02-1.05 (per year); intermediate vs. high adherence: OR 1.02, 95% CI 1.01-1.04 (per year)]. High adherence was associated with previous use of adjuvant chemotherapy (low versus high adherence OR 0.42, 95% CI 0.30-0.59) and short-term follow-up with a medical oncologist within 4 months of starting endocrine therapy (low versus high adherence OR 0.83, 95% CI 0.69-0.99). Unadjusted analysis showed increased survival among patients with high endocrine therapy adherence. However, an independent association was no longer clearly detected after controlling for confounders.

CONCLUSION

Interventions to improve adjuvant endocrine therapy adherence are warranted. Non-adherence may be a more significant issue among elderly patients. Short-term follow-up visit by a patient's medical oncologist after starting endocrine therapy may help to improve compliance.

Endocrine therapy in the years following a diagnosis of breast cancer: A proof of concept study using the primary care prescription database linked to cancer registration data

INTRODUCTION

National cancer registration data were linked to the Primary Care Prescription Database (PCPD) in England. The level of endocrine therapy (ET) prescribed in women after a diagnosis of breast cancer was studied.

MATERIALS AND METHODS

Cancer registrations for women diagnosed with breast cancer during 1995-2015, who survived to 31st March 2015, were linked to ET prescriptions issued during April-July 2015.

RESULTS

Among 369 277 survivors of breast cancer diagnosed during 1995-2015, 37% were prescribed ET during April-July 2015. Among women whose breast cancer diagnosis was after 31st July 2010, 81% of those recorded with oestrogen receptor positive (ER+ve) disease were prescribed ET compared with only 6% of those with ER-ve disease. Younger women usually received tamoxifen and older women usually received aromatase inhibitors.

DISCUSSION

The pattern of ET use observed in these data corresponds to that expected. This provides confidence in the potential of the PCPD for epidemiological research.

Drug monitoring of tamoxifen metabolites predicts vaginal dryness and verifies a low discontinuation rate from the Norwegian Prescription Database

PURPOSE

Tamoxifen is an important targeted endocrine therapy in breast cancer. However, side effects and early discontinuation of tamoxifen remains a barrier for obtaining the improved outcome benefits of long-term tamoxifen treatment. Biomarkers predictive of tamoxifen side effects remain unidentified. The objective of this prospective population-based study was to investigate the value of tamoxifen metabolite concentrations as biomarkers for side effects. A second objective was to assess the validity of discontinuation rates obtained through pharmacy records with the use of tamoxifen drug monitoring.

METHODS

Longitudinal serum samples, patient-reported outcome measures and pharmacy records from 220 breast cancer patients were obtained over a 6-year period. Serum concentrations of tamoxifen metabolites were measured by LC-MS/MS. Associations between metabolite concentrations and side effects were analyzed by logistic regression and cross table analyses. To determine the validity of pharmacy records we compared longitudinal tamoxifen concentrations to discontinuation rates obtained through the Norwegian Prescription database (NorPD). Multivariable Cox regression models were performed to identify predictors of discontinuation.

RESULTS

At the 2nd year of follow-up, a significant association between vaginal dryness and high concentrations of tamoxifen, Z-4'-OHtam and tam-NoX was identified. NorPD showed a tamoxifen-discontinuation rate of 17.9% at 5 years and drug monitoring demonstrated similar rates. Nausea, vaginal dryness and chemotherapy-naive status were significant risk factors for tamoxifen discontinuation.

CONCLUSIONS

This real-world data study suggests that measurements of tamoxifen metabolite concentrations may be predictive of vaginal dryness in breast cancer patients and verifies NorPD as a reliable source of adherence data.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Patient-reported Adherence to Adjuvant Aromatase Inhibitor Therapy Using the Morisky Medication Adherence Scale: An Evaluation of Predictors

OBJECTIVES

Endocrine therapy is part of standard adjuvant therapy for patients with hormone receptor-positive breast cancer and has been shown to improve recurrence-free and overall survival. However, adherence to endocrine therapy is suboptimal and is difficult to measure. In this study we evaluate the feasibility of using the Morisky Medication Adherence Scale (MMAS) to assess patient adherence to aromatase inhibitor (AI) therapy.

METHODS

Patients with stage 1 to 3, hormone receptor-positive breast cancer receiving adjuvant AI therapy were prospectively enrolled on an Institutional Review Board approved protocol. The MMAS questionnaire was administered to each patient and adherence was measured. Information on duration of AI therapy, patient and tumor characteristics, and treatment was collected. A multivariable logit model approach was utilized to evaluate potential barriers to adherence.

RESULTS

Between 2011 and 2014, 100 patients were enrolled. The distribution of adherence levels was 13% low, 37% medium, and 50% high. High adherence was reported more frequently in white women (58%), patients with stage 2 and 3 disease (54%), and patients who did not receive chemotherapy (62%). Multivariable analysis demonstrated that higher adherence was more likely in white women compared with African American women (estimated odds ratio=2.8).

CONCLUSIONS

Using the MMAS, only 50% of women with stage 1 to 3 breast cancer reported high adherence to AI therapy, consistent with other reports showing suboptimal adherence to adjuvant endocrine therapy. The MMAS allows for the rapid assessment of adherence to oral adjuvant endocrine therapy and is valuable in a busy clinical setting.

Good adherence to adjuvant endocrine therapy in early breast cancer - a population-based study based on the Swedish Prescribed Drug Register

INTRODUCTION

Adjuvant endocrine therapy improves recurrence-free and overall survival in primary breast cancer. However, not all patients complete their planned treatment, mostly because of side-effects. The aim of this study was to examine the adherence to adjuvant endocrine therapy in a cohort of primary breast cancer patients in Region Jönköping County, Sweden, after 3 and 5 years.

MATERIAL AND METHODS

The Swedish Breast Cancer Register was used to identify patients diagnosed with hormone receptor positive breast cancer in Region Jönköping County between 2009 and 2012. Adherence was evaluated based on data from the Swedish Prescribed Drug Register, and Medication Possession Ratio (MPR), defined as the days' supply of medication during the period from the first dispensing till the last dispensing in the time period (3 and 5 years), divided by number of days. Adherence was defined as MPR ≥80%. Regression analyses were used to identify subgroups associated with adherence; age, type of endocrine treatment, additional adjuvant therapy, and hospital responsible for the follow-up (Eksjö, Jönköping, and Värnamo).

RESULTS

We identified 634 patients who were recommended adjuvant endocrine therapy and to be able to estimate adherence after 3 and 5 years, 488 patients were included in the analysis. After 3 years of treatment, 91.2% of the patients (95% confidence interval (CI) 88.7-93.6; n = 445), were found to be adherent. The corresponding figure for the 271 patients who had completed 5 years of treatment was 91.5% (95% CI 88.2-94.8; n = 248). No subgroups (age, endocrine therapy, radio/chemotherapy, or hospital) were significantly associated with adherence in the multiple logistic regression analysis.

DISCUSSION

This study shows substantially higher adherence to adjuvant endocrine therapy than previously reported. Reasons for this could be differences in routines for therapy information and follow-up, but this needs to be further investigated.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of Changes in the Lipid Profiles of Eastern Chinese Postmenopausal Women With Early-Stage Breast Cancer Treated With Different Aromatase Inhibitors: A Retrospective Study

Cardiovascular morbidity is closely associated with serum lipid level. We aimed to investigate the effects of different aromatase inhibitors, including letrozole, anastrozole, and exemestane, on the lipid profile of eastern Chinese breast cancer patients. We evaluated a retrospective cohort of eastern Chinese postmenopausal women with early-stage breast cancer who received aromatase inhibitors. A total of 116 postmenopausal women with early-stage breast cancer without prior cardiovascular disease were included. Lipid changes at 3, 6, 12, and 24 months were compared across the endocrine therapy categories. Our data demonstrated that exemestane treatment significantly decreased triglyceride level compared with letrozole after 24 months. However, the aromatase inhibitors had almost equivalent impacts on high-density liportein cholesterol, low-density lipoprotein cholesterol, and triglyceride after long-term aromatase inhibitor treatment. As a small-size retrospective study, our data do not support a judgment about whether one AI or another carries more or less risk in terms of lipid disorders in eastern Chinese breast cancer patients. The exact effects need further randomized, controlled trials to investigate.

Can demographic, clinical and treatment-related factors available at hormonal therapy initiation predict non-persistence in women with stage I-III breast cancer?

PURPOSE

To investigate whether demographic, clinical and treatment-related risk factors known at treatment initiation can be used to reliably predict future hormonal therapy non-persistence in women with breast cancer, and to inform intervention development.

METHODS

Women with stage I-III breast cancer diagnosed 2000-2012 and prescribed hormonal therapy were identified from the National Cancer Registry Ireland (NCRI) and linked to pharmacy claims data from Ireland's Primary Care Reimbursement Services (PCRS). Non-persistence was defined as a treatment gap of ≥180 days within 5 years of initiation. Seventeen demographic, clinical and treatment-related risk factors, identified from a systematic review, were abstracted from the NCRI-PCRS dataset. Multivariate binomial models were used to estimate relative risks (RR) and risk differences (RD) for associations between risk factors and non-persistence. Calibration and discriminative performance of the models were assessed. The analysis was repeated for early non-persistence (<1 year of initiation).

RESULTS

Within 5 years of treatment initiation 680 women (19.9%) were non-persistent. Women aged <50 years (adjusted RR 1.41, 95% CI 1.16-1.70) and those prescribed antidepressants (RR 1.22, 95% CI 1.04-1.45) had increased risk of non-persistence. Married women (RR 0.82 95% CI 0.71-0.94) and those with prior medication use (RR 0.62 95% CI 0.51-0.75) had reduced risk of non-persistence. The area under the receiver-operating characteristic (ROC) curve for non-persistence was 0.61. Findings were similar for early non-persistence.

CONCLUSION

The risk prediction model did not discriminate well between women at higher and lower risk of non-persistence at treatment initiation. Future studies should consider other factors, such as psychological characteristics and experience of side-effects.

Cancer Care Coordinators to Improve Tamoxifen Persistence in Breast Cancer: How Heterogeneity in Baseline Prognosis Impacts on Cost-Effectiveness

OBJECTIVES

To assess the cost-effectiveness of a cancer care coordinator (CCC) in helping women with estrogen receptor positive (ER+) early breast cancer persist with tamoxifen for 5 years.

METHODS

We investigated the cost-effectiveness of a CCC across eight breast cancer subtypes, defined by progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) status, and local/regional spread. These subtypes range from excellent to poorer prognoses. The CCC helped in improving tamoxifen persistence by providing information, checking-in by phone, and "troubleshooting" concerns. We constructed a Markov macrosimulation model to estimate health gain (in quality-adjusted life-years or QALYs) and health system costs in New Zealand, compared with no CCC. Participants were modeled until death or till the age of 110 years. Some input parameters (e.g., the impact of a CCC on tamoxifen persistence) had sparse evidence. Therefore, we used estimates with generous uncertainty and conducted sensitivity analyses.

RESULTS

The cost-effectiveness of a CCC for regional ER+/PR-/HER2+ breast cancer (worst prognosis) was NZ $23,400 (US $15,800) per QALY gained, compared with NZ $368,500 (US $248,800) for local ER+/PR+/HER2- breast cancer (best prognosis). Using a cost-effectiveness threshold of NZ $45,000 (US $30,400) per QALY, a CCC would be cost-effective only in the four subtypes with the worst prognoses.

CONCLUSIONS

There is value in investigating cost-effectiveness by different subtypes within a disease. In this example of breast cancer, the poorer the prognosis, the greater the health gains from a CCC and the better the cost-effectiveness. Incorporating heterogeneity in a cost-utility analysis is important and can inform resource allocation decisions. It is also feasible to undertake in practice.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Persistence to 5-year hormonal breast cancer therapy: a French national population-based study

Background:

Non-persistence to oral hormonal therapy (HT) in breast cancer (BC) is an emerging health issue, and estimations vary according to the population selected and/or the statistical method applied. This study aimed to estimate non-persistence over 5 years to HT in an unselected sample of women with BC using a French national population-based database and accounting for competing risks.

Methods:

A retrospective cohort of 600 women initiating a HT between 2006 and 2007 was constituted using a representative sample of the French national healthcare insurance system database. The Cumulative Incidence Function method was used to estimate the probability of first treatment discontinuation of at least 90 days accounting for competing risk of death from any cause over the theoretical 5-year period of treatment.

Results:

Thirty one percent of patients who initiated a HT were identified as non-persistent at the fifth year of follow-up. Patients who switched to another HT (HR 3.10, 95% CI (2.20; 4.36)) or had metastatic BC (HR 3.07, 95% CI (1.73; 5.46)) were more likely to be non-persistent. Women who initiated aromatase inhibitors as compared with tamoxifen (HR 0.62, 95% CI (0.46; 0.83)), had administrative registration for BC (HR 0.21, 95% CI (0.13; 0.32)), or had received an adjuvant chemotherapy (HR 0.65, 95% CI (0.48; 0.89)) were less likely to discontinue.

Conclusions:

The estimate of long-term non-persistence in an unselected sample of women treated in France by oral hormonal therapy is substantial, even accounting for competing risks.

Use of Palliative Endocrine Therapy in Patients with Hormone Receptor-Positive Distant Metastatic Breast Cancer: How Often, How Effective, How Long?

BACKGROUND

This study provides real-world clinical evidence regarding palliative endocrine therapy (ET) in breast cancer (BC). The main questions to be answered were: how often and how long did patients receive ET? A particular aspect was the analysis of compliance and persistence with ET.

METHODS

An analysis of a nonselected/consecutive cohort of women with distant metastatic hormone receptor-positive BC (n = 205) was conducted.

RESULTS

In all, 165 patients (80.5%) received ET during the palliative disease course. The noncompliance rate was 1.5%. Sixty-seven patients (40.6%) had ET as the only antineoplastic therapy. The median number of therapy lines was 2, and the median duration was 18 months. The median metastatic disease survival (MDS) was 34 months. In patients who had an MDS of ≥9 months (n = 145; 87.9%), during 70.6% of the MDS time only ET had been administered. Patients who were naïve to ET more often had a good response to and a longer duration of palliative ET than those who were not. The nonpersistence rate was 4.3%.

CONCLUSIONS

Excluding the few patients who had a rapidly progressive course, the disease was controlled for about 70% of the entire palliative disease course with ET alone. Only very few patients were nonpersistent with ET and consciously stopped a still effective, ongoing ET.

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

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

Comparative adherence to oral hormonal agents in older women with breast cancer

We aim to (1) compare compliance of anastrozole, letrozole, exemestane, and tamoxifen in women and (2) identify clinical factors associated with medication non-adherence and non-persistence. Female Medicare beneficiaries who were new users of anastrozole, letrozole, exemestane, or tamoxifen between 2007 and 2010 were analyzed. Multivariate-modified Poisson and Cox regression models were constructed to compare non-adherence and non-persistence, respectively, across the different oral agents. A total of 5,150 women were included: mean age was 76.4 years, 2352 initiated anastrozole, 1401 letrozole, 248 exemestane, and 1149 tamoxifen. Non-adherence and non-persistence were 41 and 49% respectively, with exemestane being associated with the worst non-adherence and non-persistence (RR 1.57, 95% CI 1.37-1.80, p < 0.001; HR 1.93, 95% CI 1.63-2.30, respectively, p < 0.001), followed by letrozole (RR 1.39, 95% CI 1.26-1.53, p < 0.001; HR 1.47, 95% CI 1.32-1.64, respectively, p < 0.001), and anastrozole (RR 1.16, 95% CI 1.05-1.27, p = 0.003; HR 1.14, 95%CI 1.03-1.27, respectively, p = 0.011), whereas tamoxifen was associated with the best compliance. Use of statins and osteoporosis medications was correlated with improved adherence (RR 0.89, 95 % CI 0.82-0.96, p = 0.002 and RR 0.84, 95 % CI 0.76-0.92, p < 0.001, respectively, for non-adherence) and persistence (HR 0.86, 95 % CI 0.79-0.94, p < 0.001 and HR 0.86, 95 % CI 0.78-0.96, p = 0.005, respectively, for non-persistence), but chronic kidney disease was correlated with worse non-persistence (HR 1.15, 95 % CI 1.04-1.33, p = 0.04). Age ≥ 70 years was also associated with worse compliance. Compliance to oral hormonal therapy varied depending on the type of agent, age, and concurrent medications, highlighting specific opportunities to improve adherence and persistence in older women with breast cancer.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Identifying the determinants of adjuvant hormonal therapy medication taking behaviour in women with stages I-III breast cancer: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to identify the modifiable determinants of adjuvant hormonal therapy medication taking behaviour (MTB) in women with stage I-III breast cancer in clinical practice settings.

METHODS

We searched PubMed EMBASE, PsycINFO and CINAHL for articles investigating determinants of adjuvant hormonal therapy. Potentially modifiable determinants were identified and mapped to the 14 domains of the Theoretical Domains Framework (TDF), an integrative framework of theories of behavioural change. Meta-analysis was used to calculate pooled odds ratios for selected determinants.

RESULTS

Potentially modifiable determinants were identified in 42 studies and mapped to 9 TDF domains. In meta-analysis treatment side-effects (Domain: Beliefs about Capabilities) and follow-up care with a general practitioner (vs. oncologist) (Social Influences) were significantly negatively associated with persistence (p<0.001) and number of medications (Behaviour Regulation) was significantly positively associated with persistence (p<0.003). Studies did not examine several domains (including Beliefs about Consequences, Intentions, Goals, Social Identity, Emotion and Knowledge) which have been reported to influence MTB in other disease groups.

CONCLUSIONS

There is some evidence that the domains Beliefs about Capabilities, Behaviour Regulation and Social Influences influence hormonal therapy MTB.

PRACTICE IMPLICATIONS

Further research is needed to develop effective interventions to improve hormonal therapy MTB.

Risks of nonadherence to hormone therapy in Asian women with breast cancer

The aim of this study was to quantify the hormone therapy (HT) nonadherence patterns and to assess the associated risk factors in Asian women with breast cancer. This retrospective cohort study used the Taiwan Health Insurance Research Database from 2003 to 2011. Data from women with newly diagnosed primary breast cancer were identified, and persistence (without HT prescribing gap ≥ 180 days) to HT was defined through records of dispensing prescriptions. Study cohorts were further classified as adjuvant and primary HT groups. Each individual's HT utilization patterns and the medication possession ratio at overall HT course were measured. The odds ratios (ORs) of nonadherence (medication possession ratio, <80%) in adjuvant and primary HT patients were estimated using logistic regressions with adjustment of potential confounding variables. These patients had 15.6% and 23.4% nonadherence rates to HT in adjuvant and primary HT groups, respectively. In the adjuvant HT group, older age groups (≥50 years) and taking aromatase inhibitors were less likely to show nonadherence (p < 0.05). In the primary HT group, women older than 70 years were significantly less likely to exhibit nonadherence (OR = 0.53; 95% confidence interval, 0.28-0.99); however, women with presence of HT-related adverse events had significantly increased risk (OR = 1.44; 95% confidence interval, 1.02-2.03). Young age and experience of musculoskeletal and joint symptoms were identified as risk factors for nonadherence.

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

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

Socio-demographic and geographic variations in the utilization of hormone therapy in older women with breast cancer after Medicare Part-D coverage

No study has previously reported the utilization and adherence to hormone therapy for Medicare Part-D beneficiaries with breast cancer. This study was conducted using the Surveillance, Epidemiology, and End Results-Medicare-linked data to assess socio-demographic, geographic, and other variations in the receipt of hormone therapy among patients with hormone receptor-positive breast cancer and to assess adherence to hormone therapy within 1-year follow-up. The percentage of patients who received hormone therapy was calculated and stratified by chemotherapy status (yes or no). Logistic regression models were performed to assess the variations associated with the use of selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), and hormone therapy (SERMs or AIs). Of 25,128 women with hormone receptor-positive breast cancer in 2006-2009 who were enrolled in Medicare Part-D program, 70.8 % received hormone therapy, 22.2 % received SERM, and 56.9 % received AIs. Among those receiving chemotherapy, significant predictors of receiving hormone therapy included age, tumor stage, surgery type, radiation therapy; significant predictors of receiving SERM included race, year of diagnosis, and tumor stage; and significant predictors of receiving AI included age, race, socioeconomic status, geographic location, tumor stage, and radiation therapy. For those without receiving chemotherapy, most of the above factors were significant, but differed across each drug class. In conclusion, over two-thirds of hormone receptor-positive breast cancer patients received hormone therapy, and still 29.2 % of patients did not receive it. Tumor and clinical factors are the most significant predictors for the receipt of hormone therapy.

Factors influencing treatment adherence and discontinuation in women with breast cancer

SUMMARY 

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

Discontinuation and non-adherence to endocrine therapy in breast cancer patients: is lack of communication the decisive factor?

INTRODUCTION

Non-adherence to anti-hormonal therapy is a major problem in gynecologic oncology. Reasons reported are side effects and lack of support. The aim of our study was an analysis of influence of experiences of patients with endocrine therapy and communication and information on this topic and their influence on adherence.

METHODS

We developed a structured questionnaire which was tested in a pilot version and then programmed as online questionnaire and presented to patient members of self-help and breast cancer organizations.

RESULTS

Patients only had received scarce information on endocrine therapy. Only 12.8% stated that their questions were answered in detail, 43.2% got no answers or only non-detailed answers. 76% had side effects limiting functions of daily life. 60% of physicians did not react on these side effects. There is a significant correlation between number and intensity of side effects and non-adherence or disruption of therapy (p = 0.029 and p < 0.01, respectively). Women who reported having received detailed answers to their questions also reported better adherence (p = 0.014).

CONCLUSION

In order to improve adherence, detailed information on side effects and answers in case of symptoms are most important. Physicians should not rely on presenting written information but should mainly engage in direct communication.

Early discontinuation of endocrine therapy for breast cancer: who is at risk in clinical practice?

PURPOSE

Despite evidence supporting at least five years of endocrine therapy for early breast cancer, many women discontinue therapy early. We investigated the impact of initial therapy type and specific comorbidities on discontinuation of endocrine therapy in clinical practice.

METHODS

We identified women in a population-based cohort with a diagnosis of early breast cancer and an incident dispensing of anastrozole, letrozole or tamoxifen from 2003-2008 (N = 1531). Pharmacy and health service data were used to determine therapy duration, treatment for pre-existing and post-initiation comorbidities (anxiety, depression, hot flashes, musculoskeletal pain, osteoporosis, vaginal atrophy), demographic and other clinical characteristics. Time to discontinuation of initial, and any, endocrine therapy was calculated. Cox regression determined the association of different characteristics on early discontinuation.

RESULTS

Initial endocrine therapy continued for a median of 2.2 years and any endocrine therapy for 4.8 years. Cumulative probability of discontinuing any therapy was 17% after one year and 58% by five years. Initial tamoxifen, pre-existing musculoskeletal pain and newly-treated anxiety predicted shorter initial therapy but not discontinuation of any therapy. Early discontinuation of any therapy was associated with newly-treated hot flashes (HR = 2.1, 95% CI = 1.3-3.3), not undergoing chemotherapy (HR = 1.4, 95% CI = 1.1-1.8) and not undergoing mastectomy (HR = 1.5, 95% CI = 1.2-1.8).

CONCLUSIONS

Less than half of women completed five years of endocrine therapy. Women at greatest risk of stopping any therapy early were those with newly-treated hot flashes, no initial chemotherapy, or no initial mastectomy. This suboptimal use means that the reductions in recurrence demonstrated in clinical trials may not be realised in practice.

Adherence to endocrine therapy in breast cancer adjuvant and prevention settings

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

Complementary or alternative medicine as possible determinant of decreased persistence to aromatase inhibitor therapy among older women with non-metastatic breast cancer

PURPOSE

Aromatase inhibitor therapy (AI) significantly improves survival in breast cancer patients. Little is known about adherence and persistence to aromatase inhibitors and about the causes of treatment discontinuation among older women.

METHODS

We constituted a cohort of women over 65 receiving a first AI therapy for breast cancer between 2006 and 2008, and followed them until June 2011. Women were selected in the population-based French National Health Insurance databases, and data was collected on the basis of pharmacy refills, medical records and face-to-face interviews. Non-persistence to treatment was defined as the first treatment discontinuation lasting more than 3 consecutive months. Time to treatment discontinuation was studied using survival analysis techniques.

RESULTS

Overall among the 382 selected women, non-persistence to treatment went from 8.7% (95%CI: 6.2-12.1) at 1 year, to 15.6% (95%CI: 12.2-19.8) at 2 years, 20.8% (95%CI: 16.7-25.6) at 3 years, and 24.7% (95%CI: 19.5-31.0) at 4 years. In the multivariate analysis on a sub-sample of 233 women with available data, women using complementary or alternative medicine (CAM) (HR = 3.2; 95%CI: 1.5-6.9) or suffering from comorbidities (HR = 2.2; 95%CI: 1.0-4.8) were more likely to discontinue their treatment, whereas women with polypharmacy (HR = 0.4; 95%CI: 0.2-0.91) were less likely to discontinue. In addition, 13% of the women with positive hormonal receptor status did not fill any prescription for anti-hormonal therapy.

CONCLUSION

AI therapy is discontinued prematurely in a substantial portion of older patients. Some patients may use CAM not as a complementary treatment, but as an alternative to conventional medicine. Improving patient-physician communication on the use of CAM may improve hormonal therapy adherence.

[The importance of adherence to oral therapies in the field of oncology: the example of breast cancer]

Today, over 40 different oral anticancer therapies are available in the French prescription pricing authority dictionary. Adherence to these therapies has become a major issue in the field of oncology. Most of the available research has focused on adherence to hormonal therapy for breast cancer (BC). The objective of this paper is to synthesize current knowledge on adherence and persistence to hormonal therapy for BC. Available studies display significant heterogeneity due to variability in the measurements and data sources used, as well as in the timing of the measurements. Adherence and persistence estimates have recently been summarized in a meta-regression analysis. For tamoxifen, adherence ranges from 79% at one year to 65% at five years, and for Aromatase Inhibitors (AI), from 80% at one year to 72% at five years. Persistence decreases with the increasing duration of treatment: from a high of 86% of patients persistent at 1 year to a low of 53% at five years for tamoxifen, and from 88% to 69% for AI. Some of the modifiable determinants of adherence are directly linked to the patient-physician relation, to information provided during consultations, or to the specialty of the physician involved in the patient follow-up. Non-modifiable determinants, such as age or comorbidities, can be used to identify sub-groups of patients at high risk of non-adherence in order to target interventions. Few trials have been conducted in oncology to evaluate the efficacy of interventions to improve adherence. Adherence directly impacts both the efficacy of treatment and long-term treatment costs. Interventions to improve adherence to oral therapies should be systematically promoted in oncology. Improving adherence should be considered a priority in the field, lest physicians continue writing inefficient prescriptions for highly efficacious treatments.

Predictors of non-adherence to systemic oral therapy for advanced hepatocellular carcinoma

OBJECTIVES

With increasing use and cost of oral oncology medications, patient non-adherence with oral therapy is of concern. This study evaluated non-adherence among patients receiving first-line oral therapy for hepatocellular carcinoma (HCC).

METHODS

This retrospective study used the employer-based MarketScan medical and pharmacy claims database (2005-2011) to identify adult patients with two or more diagnoses of HCC (ICD-9 155), and two or more filled prescriptions for sorafenib. Additional eligibility requirements were not having other previous cancers and a 4 month wash-out period prior to the index sorafenib date. Adherence was assessed using a modified proportion of days covered (PDC) measure with patient-specific sorafenib exposure from index date to treatment discontinuation. Non-adherence was categorized as PDC <85% (base case), with sensitivity analyses using an 80% cut-off and allowance for physician-directed therapy gaps. Logistic regression models were estimated to identify predictors of non-adherence.

RESULTS

A total of 1127 patients (median age = 61.0 years; 78.4% male) met eligibility criteria. Median duration of enrollment was 223 days and median sorafenib exposure was 121 days. Between 21.1% (PDC < 0.80) and 28.0% (PDC < 0.85) of patients were non-adherent. Higher age (p = 0.022), number of baseline medications (p = 0.003) and number of baseline comorbidities (p = 0.002) were associated with lower non-adherence, while prior procedures were associated with greater non-adherence (p = 0.002).

LIMITATIONS

In this study using billing claims data, we were unable to evaluate patient severity in terms of clinical characteristics such as the Child-Pugh score. Similarly, we could not assess clinical outcomes such as tumor response, radiological progression or overall survival, although median duration of sorafenib exposure and duration of health plan enrollment respectively were found to be good proxies.

CONCLUSIONS

Using a modified PDC approach, 22-29% of patients were non-adherent. Identified predictors of non-adherence in HCC should be assessed for newly emerging oral therapies, and may be used to guide patient education and other adherence-enhancing initiatives.

Adherence and discontinuation of oral hormonal therapy in patients with hormone receptor positive breast cancer

BACKGROUND

Oral treatment in women with breast cancer has been increasingly used. However, a potentially negative side of oral medication is poor patient adherence and/or discontinuation, which reduces the treatment effectiveness, accelerating progression of the disease and reducing the patient survival rate.

AIM OF THE REVIEW

To compare the rates of adherence and/or discontinuation and the methodologies used to assess these outcomes. It was conducted an integrative review of original articles published from 2000 to 2012, in which their primary outcome was to quantify medication adherence and/or discontinuation of oral hormonal therapy in patients with hormone receptor positive breast cancer.

METHODS

Original studies were searched in the PubMed/MEDLINE, Scopus, Embase and SciELO databases. The Medical Subject Heading was used to define descriptors. The descriptor "breast neoplasms" was used in all combinations. Each of the descriptors "medication adherence" and "patient compliance" were combined with each of the following descriptors "tamoxifen", "aromatase inhibitors", "selective estrogen receptor modulators", or the terms "letrozole", "anastrozole", and "exemestane".

RESULTS

Twenty-four original articles were included. Our study showed a wide range of adherence and discontinuation rates, ranging from 45-95.7 and 12-73 %, respectively. Regarding the methodological development of the selected articles, a high prevalence (87.5 %) of prospective and/or retrospective longitudinal studies was found. In addition, there was a high prevalence of studies using a database (70.8 %). Among some of the studies, it was shown that patient adherence to hormonal therapy gradually reduces, while discontinuation increases during the treatment.

CONCLUSIONS

It was observed a great diversity among rates of adherence and/or discontinuation of hormonal therapy for breast cancer, which may be due to a lack of methodology standardization. Therefore, adequate and validated methods to ensure reliability of the results and allow comparison in the literature are needed. Furthermore, adherence decreases and discontinuation increases over time, suggesting the need for patient continuous education and a pharmacotherapeutic follow up by health professionals to improve these clinical outcomes.

Patient-reported discontinuation of endocrine therapy and related adverse effects among women with early-stage breast cancer

BACKGROUND

Approximately 20% to 50% of women diagnosed with hormone receptor-positive breast cancer discontinue endocrine therapy early; most reports come from automated pharmacy data or small self-report evaluations. We conducted a larger self-report evaluation of endocrine therapy discontinuation associated with patient characteristics and therapy-related adverse effects.

METHODS

We surveyed 538 women from a single health plan who were diagnosed with early-stage breast cancer from 2002 to 2008 and received endocrine therapy. Women reported adverse effects and reasons for discontinuation via mailed survey; tumor characteristics were obtained via registry linkage. We classified women as discontinuers if they self-reported stopping therapy and their self-reported duration of tamoxifen plus aromatase inhibitor (AI) use was < 5 years, and nondiscontinuers if they self-reported ≥ 5 years use or current use. We estimated odds ratios (ORs) with 95% CIs for discontinuation versus continuation by using logistic regression adjusted for age and year of diagnosis.

RESULTS

Among 538 women, 98 (18.2%) discontinued endocrine therapy early. Women with positive lymph nodes (v negative) were significantly less likely to discontinue therapy (odds ratio [OR] = 0.54; 95% CI, 0.31 to 0.93). Almost all women (94%) experienced adverse effects. Experiencing headaches was associated with discontinuation of AIs (OR = 4.16; 95% CI, 2.16 to 8.01) and tamoxifen (OR = 2.34; 95% CI, 1.24 to 4.41); few other individual adverse effects were related to discontinuation despite most discontinuers reporting they "did not like adverse effects" (AIs: 66.7%, tamoxifen: 59.1%).

CONCLUSION

Few individual adverse effects or patient characteristics were significantly associated with endocrine therapy discontinuation, yet adverse effects were prevalent and were the most common reason women reported for discontinuing therapy.

A feasibility study to evaluate breast cancer patients' knowledge of their diagnosis and treatment

OBJECTIVE

To evaluate the feasibility of an electronic survey to assess patients' knowledge of their breast cancer and treatment, and interest in receiving a medical summary.

METHODS

Women undergoing breast cancer treatment completed an interviewer-administered electronic survey in person or by telephone. Medical records were abstracted to evaluate knowledge accuracy.

RESULTS

Among 38 eligible patients approached for the study, 35 (92%) participated and 33 (94%) completed the survey. Participants' perceived knowledge tended to be greater than their actual knowledge. Reporting of clinicopathologic features was most accurate for stage (91%) and lymph node status (88%), and least accurate for tumor size (61%), type (61%), and grade (33%). Accurate reporting of tumor receptor over-expression varied from 76% (estrogen receptor) to 39% (progesterone receptor). Many patients correctly recalled general treatment modalities and details of surgery; fewer recalled details of radiation and chemotherapy. Importantly, nearly all (32/33) were interested in receiving a breast cancer medical summary.

CONCLUSION

An electronic survey is feasible to assess breast cancer patients' knowledge. This data suggest that patients have gaps in knowledge and would like a personalized medical summary.

PRACTICE IMPLICATIONS

Larger studies are needed to validate and characterize knowledge gaps, and test interventions to improve physician-patient information sharing.

Adherence evaluation of endocrine treatment in breast cancer: methodological aspects

Background

Current studies on adherence to endocrine therapy in breast cancer patients suffer from methodological limitations due to a lack of well-validated methods for assessing adherence. There is no gold standard for measuring adherence. The aim of our study was to compare four different approaches for evaluating adherence to anastrozole therapy for breast cancer with regard to concordance between methods.

Methods

Outpatients with early breast cancer treated with anastrozole completed the multi-method assessment of adherence. We implemented a self-report scale (the Simplified Medication Adherence Questionnaire), physician- ratings, refill records and determination of anastrozole serum concentration.

Results

Comparison of the four approaches using Spearman rank correlation revealed poor concordance across all methods reflecting weak correlations of 0.2-0.4. Considering this data incomparability across methods, we still observed high adherence rates of 78%-98% across measures.

Conclusion

Our findings contribute to the growing body of knowledge on the impact that methodological aspects exert on the results of adherence measurement in breast cancer patients receiving endocrine treatment. Our findings suggest that the development and validation of instruments specific to patients receiving endocrine agents is imperative in order to arrive at a more accurate assessment and to subsequently obtain more precise estimates of adherence rates in this patient population.