Adherence to adjuvant endocrine therapy in postmenopausal women with breast cancer

Department of Gynaecology, Gynaecological Endocrinology and Oncology, Philipps-University of Marburg, Marburg, Germany.
Annals of Oncology (Impact Factor: 7.04). 03/2009; 20(3):431-6. DOI: 10.1093/annonc/mdn646
Source: PubMed


The level of adherence of various pharmacological therapies in chronic diseases varies, but is predominantly low. With tamoxifen (TAM), 23% and 50% nonadherence after 1 and 4 years have been reported. Day-to-day clinical observation suggests that adherence may even be lower with aromatase inhibitors, but limited data exist on the situation in daily clinical routine. The aim of this study was to evaluate the rate of adherent patients in a randomly selected sample of postmenopausal women with primary breast cancer, who had been assigned to an adjuvant endocrine treatment with TAM or anastrozole (ANA).
We investigated a random sample of 100 postmenopausal women with breast cancer (50 TAM and 50 ANA) who had received surgery for their primary breast cancer at our hospital in 2004/2005 and thereafter had been assigned to an adjuvant endocrine treatment. We evaluated the adherence rate with a detailed questionnaire and additionally carried out a retrospective prescription check of the hospital chart as well as calling the local physicians of our patients. A patient was counted as adherent with a self-reported tablet intake of 80% or more and if a medication possession ratio of 80% or more was achieved.
Regarding the baseline characteristics, a significant difference in mean age was noticed in women on ANA versus TAM [65 (+/-3) and 72 (+/-3); P<0.001]. All women on TAM and ANA reported to be adherent (100%). After controlling for prescriptions, only 40 (80%) and 27 (69%) of the women on TAM and ANA were still classified as adherent (P<0.01 and P<0.01 versus self-report). We found no significant correlation of adherence to any baseline characteristics or side-effects in a logistic regression model.
An important goal of any therapeutic intervention is to achieve comparable efficacy in routine clinical practice to that demonstrated in randomised clinical trials. However, a similar magnitude of adherence will be necessary in routine clinical practice to assure comparable clinical effects. Our results further support the data on suboptimal adherence of women with breast cancer on adjuvant TAM treatment. Here, we evaluated for the first time the patient reported and real-world adherence on adjuvant ANA and were able to show a similarly low adherence compared with TAM. More prospective studies are needed to increase our understanding of the underlying reasons for nonadherence in women with breast cancer.

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Available from: Peyman Hadji, Dec 17, 2013
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    • "Currently, there is no gold standard to measure adherence in clinical practice and no exclusively operational definition of good adherence [16] [17]. The medication possession ratio (MPR) is a common measure of adherence in longitudinal studies; conventionally, an MPR < 80% is considered nonadherence [18] [19]. The nonadherence rate of HT changes over time and may be influenced by multiple factors, such as the improvement in symptoms or the experiencing of adverse effects [20]. "
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    ABSTRACT: 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. Copyright © 2015. Published by Elsevier Taiwan.
    The Kaohsiung journal of medical sciences 05/2015; 31(6). DOI:10.1016/j.kjms.2015.04.002 · 0.80 Impact Factor
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    • "Another limitation of our study is that adherence to tamoxifen was assessed through selfreported information from patients at visits, which was not verified with information on prescription and dispensation. It is well known that adherence to tamoxifen decreases alarmingly after the first year of therapy and that patients tend to overstate their own adherence [32] "
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    ABSTRACT: Background CYP2D6 is a key enzyme in tamoxifen metabolism, transforming it into its main active metabolite, endoxifen. Poor CYP2D6 metabolizers (PM) have lower endoxifen plasma concentrations and possibly benefit less from treatment with tamoxifen. We evaluated tamoxifen dose adjustment in CYP2D6 PM patients in order to obtain plasma concentrations of endoxifen comparable to patients with extensive CYP2D6 metabolism (EM). Patients and methods Comprehensive CYP2D6 genotyping and plasma tamoxifen metabolite concentrations were performed among 249 breast cancer patients in adjuvant treatment with tamoxifen. Tamoxifen dose was increased in PM patients to 40 mg and to 60 mg daily for a 4-month period each, repeating tamoxifen metabolite measurements on completion of each dose increase. We compared the endoxifen levels between EM and PM patients, and among the PM patients at each dose level of tamoxifen (20, 40 and 60 mg). Results Eleven PM patients (4.7%) were identified. The mean baseline endoxifen concentration in EM patients (11.30 ng/ml) was higher compared to the PM patients (2.33 ng/ml; p < 0.001). In relation to the 20 mg dose, increasing the tamoxifen dose to 40 and 60 mg in PM patients significantly raised the endoxifen concentration to 8.38 ng/ml (OR 3.59; p = 0.013) and to 9.30 ng/ml (OR 3.99; p = 0.007), respectively. These concentrations were comparable to those observed in EM patients receiving 20 mg of tamoxifen (p = 0.13 and p = 0.64, respectively). Conclusion In CYP2D6 PM patients, increasing the standard tamoxifen dose two-fold or three-fold raises endoxifen concentrations to levels similar to those of patients with EM phenotype.
    Breast (Edinburgh, Scotland) 08/2014; 23(4). DOI:10.1016/j.breast.2014.02.008 · 2.38 Impact Factor
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    • "This finding might be due to the frequent musculoskeletal toxicity associated with AIS [30]. Other studies have found no statistically significant differences between the different types of hormone therapy and adherence [31,32], although a lower adherence rate has been noted for anastrozole than for TMX [32]. It is noteworthy that in the current study cohort, the majority (64.4%) of the women were treated with TMX alone, while 29.8% received a combination of TMX and AIS and a few women (5.8%) were treated only with AIS. "
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    ABSTRACT: Background Despite the excellent results obtained with hormone therapy, the long treatment period and the side effects associated with its use make patient adherence difficult. Moreover, certain aspects of health care can mitigate or exacerbate non-adherence. This study aimed to identify the factors associated with adherence to hormone therapy for breast cancer, with the goal of contributing to the reformulation of the care process and to improvements in outcomes. Method This was a retrospective longitudinal study based on secondary data. The study integrated and analyzed data from a cohort of 5,861 women with breast cancer who were identified in the databases of the Brazilian National Cancer Institute [Instituto Nacional de Câncer - INCA] and the Unified Health System [Sistema Único de Saúde - SUS]. All of the patients were treated at INCA, which dispenses free medication, and the follow-up period lasted from 01/01/2004 to 10/29/2010. The outcome of interest was hormone treatment adherence, which was defined as the possession of medication, and a logistic regression model was employed to identify the socio-demographic, behavioral, clinical, and health care variables that were independently associated with the variations in this outcome. Results The proportion of women who adhered to hormone therapy was 76.3%. The likelihood of adherence to hormone therapy increased with each additional year of age, as well as among women with a secondary or higher level education, those with a partner, those who underwent surgery, those who had more consultations with a breast specialist and clinical oncologist, and those who underwent psychotherapy; the effect for the latter increased with each additional consultation. Conversely, the likelihood of adherence was lower among patients at a non-curable stage, those who were alcohol drinkers, those who received chemotherapy, those who had undergone more tests and had more hospitalizations, and those who used tamoxifen and combined aromatase inhibitors. Conclusion This study shows that approximately a quarter of the women with breast cancer did not adhere to hormone treatment, thus risking clinical responses below the expected standards. It also identifies the most vulnerable subgroups in the treatment process and the aspects of care that provide better results.
    BMC Cancer 06/2014; 14(1):397. DOI:10.1186/1471-2407-14-397 · 3.36 Impact Factor
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