Use of a urine anastrozole assay to determine treatment discontinuation among women with hormone-sensitive breast cancer: a pilot study

Patient-Reported Outcomes and Long-Term Nonadherence to Aromatase Inhibitors

BACKGROUND

Nonadherence to aromatase inhibitors (AIs) is common and increases risk of breast cancer (BC) recurrence. We analyzed factors associated with nonadherence among patients enrolled in S1105, a randomized trial of text messaging.

METHODS

At enrollment, patients were required to have been on an adjuvant AI for at least 30 days and were asked about financial, medication, and demographic factors. They completed patient-reported outcomes (PROs) representing pain (Brief Pain Inventory), endocrine symptoms (Functional Assessment of Cancer Therapy-Endocrine Symptoms), and beliefs about medications (Treatment Satisfaction Questionnaire for Medicine; Brief Medication Questionnaire). Our primary endpoint was AI nonadherence at 36 months, defined as urine AI metabolite assay of less than 10 ng/mL or no submitted specimen. We evaluated the association between individual baseline characteristics and nonadherence with logistic regression. A composite risk score reflecting the number of statistically significant baseline characteristics was examined.

RESULTS

We analyzed data from 702 patients; median age was 60.9 years. Overall, 35.9% patients were nonadherent at 36 months. Younger patients (younger than age 65 years) were more nonadherent (38.8% vs 28.6%, odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.05 to 2.16; P = .02). Fourteen baseline PRO scales were each statistically significantly associated with nonadherence. In a composite risk model categorized into quartile levels, each increase in risk level was associated with a 46.5% increase in the odds of nonadherence (OR = 1.47, 95% CI =1.26 to 1.70; P < .001). The highest-risk patients were more than 3 times more likely to be nonadherent than the lowest-risk patients (OR = 3.14, 95% CI = 1.97 to 5.02; P < .001).

CONCLUSIONS

The presence of multiple baseline PRO-specified risk factors was statistically significantly associated with AI nonadherence. The use of these assessments can help identify patients for targeted interventions to improve adherence.

Randomized Trial of Text Messaging to Reduce Early Discontinuation of Adjuvant Aromatase Inhibitor Therapy in Women With Early-Stage Breast Cancer: SWOG S1105

PURPOSE

Nonadherence to aromatase inhibitors (AIs) for breast cancer is common and increases the risk of recurrence. Text messaging increases adherence to medications for chronic conditions.

METHODS

We conducted a randomized clinical trial of text messaging (TM) versus no text messaging (No-TM) at 40 sites in the United States. Eligible patients were postmenopausal women with early-stage breast cancer taking an AI for > 30 days with a planned duration of ≥ 36 months. Test messages were sent twice a week over 36 months. Content themes focused on overcoming barriers to medication adherence and included cues to action, statements related to medication efficacy, and reinforcements of the recommendation to take AIs. Both groups were assessed every 3 months. The primary outcome was time to adherence failure (AF), where AF was defined as urine AI metabolite assay results satisfying one of the following: < 10 ng/mL, undetectable, or no submitted specimen. A stratified log-rank test was conducted. Multiple sensitivity analyses were performed.

RESULTS

In total, 724 patients were registered between May 2012 and September 2013, among whom,702 patients (348 in the text-messaging arm and 354 in the no-text-messaging arm) were eligible at baseline. Observed adherence at 36 months was 55.5% for TM and 55.4% for No-TM. The primary analysis showed no difference in time to AF by arm (3-year AF: 81.9% TM v 85.6% No-TM; HR, 0.89 [95% CI, 0.76 to 1.05]; P = .18). Multiple time to AF sensitivity analyses showed similar nonsignificant results. Three-year self-reported time to AF (10.4% v 10.3%; HR, 1.16 [95% CI, 0.69 to 1.98]; P = .57) and site-reported time to AF (21.9% v 18.9%; HR, 1.31 [95% CI, 0.86 to 2.01]; P = .21) also did not differ by arm.

CONCLUSION

To our knowledge, this was the first large, long-term, randomized trial of an intervention directed at improving AI adherence. We found high rates of AI AF. Twice-weekly text reminders did not improve adherence to AIs. Improving long-term adherence will likely require personalized and sustained behavioral interventions.

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPLICATIONS FOR CANCER SURVIVORS

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

The use of mass spectrometry for analysing metabolite biomarkers in epidemiology: methodological and statistical considerations for application to large numbers of biological samples

Data quality is critical for epidemiology, and as scientific understanding expands, the range of data available for epidemiological studies and the types of tools used for measurement have also expanded. It is essential for the epidemiologist to have a grasp of the issues involved with different measurement tools. One tool that is increasingly being used for measuring biomarkers in epidemiological cohorts is mass spectrometry (MS), because of the high specificity and sensitivity of MS-based methods and the expanding range of biomarkers that can be measured. Further, the ability of MS to quantify many biomarkers simultaneously is advantageously compared to single biomarker methods. However, as with all methods used to measure biomarkers, there are a number of pitfalls to consider which may have an impact on results when used in epidemiology. In this review we discuss the use of MS for biomarker analyses, focusing on metabolites and their application and potential issues related to large-scale epidemiology studies, the use of MS "omics" approaches for biomarker discovery and how MS-based results can be used for increasing biological knowledge gained from epidemiological studies. Better understanding of the possibilities and possible problems related to MS-based measurements will help the epidemiologist in their discussions with analytical chemists and lead to the use of the most appropriate statistical tools for these data.

Oral cancer chemotherapy adherence and adherence assessment tools: a report from North Central Cancer Group Trial N0747 and a systematic review of the literature

Oncologists are now prescribing more oral chemotherapy than ever before, thus placing the onus for taking the right dose at the right time under the right circumstances directly on the patient. This study was undertaken to understand emerging adherence issues and to explore available adherence assessment tools. This two-part study (1) examined N0747, a randomized phase II trial that tested the oral agents, sunitinib and capecitabine, in patients with metastatic esophageal cancer from an adherence standpoint, and (2) conducted a systematic review to compile and assess adherence tools that can be used in future clinical trials. First, in N0747, patients were assigned to sunitinib and capecitabine versus capecitabine; 53 chemotherapy cycles were prescribed to this 12-patient cohort. Nearly all patients denoted that they "always or almost always" took their pills as prescribed, and two patients who reported lack of full adherence suffered from grade 3+ adverse events. Surprisingly, however, over 14 cycles, 9 patients reported grade 3+ toxicity but checked "always or almost always" to describe their adherence. No relationships were observed between adherence and cancer outcomes. Secondly, 21 articles identified the following adherence tools: (1) healthcare providers' interviews, (2) patient-reported adherence with diaries/calendars, (3) patient-completed adherence scales, (4) medication event monitoring, (5) automated voice response, (6) drug/metabolite assays, and (7) prescription databases. Of note, only the automated voice response seems capable of real-time detection of over-adherence, as observed in N0747. Oral chemotherapy adherence should be further studied, particularly from the standpoint of over-adherence.

Adjuvant aromatase inhibitor therapy in patients with stage I breast cancer at a regional oncology center in Israel: implementation of a 'switching' policy in postmenopausal patients after initial tamoxifen

OBJECTIVE

To analyze the implementation of a switching policy of adjuvant aromatase inhibitor (AI) therapy sequentially after tamoxifen in consecutively treated stage I (T1N0M0) hormone receptor (HR)-positive breast cancer (BC) patients.

METHODS

The records of 279 consecutive HR-positive BC patients diagnosed between 2002 and 2006 and followed at the Soroka Medical Center were reviewed.

RESULTS

Two-hundred-seventeen patients who initially received tamoxifen were suitable for switching and 28 received an AI as initial adjuvant treatment. The switch was accomplished in 82.5% of the 217 patients. Those who switched to an AI had a higher proportion of T1c stage than patients eligible who were not switched, but did not differ in age, histologic grade, or having received chemotherapy. Of the 179 patients who switched, 155 (86.6%) completed at least 4.5-5 years of adjuvant tamoxifen/AI therapy. Eighteen patients discontinued AI therapy prematurely because of toxicity.

CONCLUSIONS

In this stage I BC population, despite the toxicities of AI therapy, >84% of eligible patients received an AI as adjuvant therapy. Measures to improve the management of AI toxicity, such as changing to a different AI, may reduce early stopping.