Background
Metastatic breast cancer (MBC), also referred to as secondary or advanced breast cancer, is defined as breast cancer that has spread to other parts of the body [
1]. MBC is currently incurable; however, it can be managed as a chronic disease with appropriate treatment strategies [
2]. The systematic treatment options for MBC are endocrine therapy, chemotherapy, and biological (targeted) therapy [
3]. The goals of care are to control disease progression, extend survival, optimize symptom management, and enhance the quality of life [
3‐
5]. A previous study suggested that patients with MBC are willing to accept substantial risks of side effects in exchange for potential survival benefits [
5].
As oral anticancer agents are becoming more common, a critical shift has occurred from clinic-based healthcare provider-administered management to home-based self-administered management, with patient adherence becoming increasingly important [
6]. There are very few studies on adherence to medication in patients with MBC, and the results are inconsistent. Although Figueiredo et al. reported high adherence to capecitabine in patients with MBC [
7], Di Bonaventura et al. addressed nonadherent beheviours due to forgetfulness and intolerance of side effects in an internet-based study on multiple anti-cancer drugs [
5]. Schulman-Green et al. [
8] addressed barriers to self-management in patients with MBC, including symptom distress, difficulty in obtaining information and lack of knowledge about the course of cancer. Cancer survivors have unmet needs concerning personal control (e.g., maintaining autonomy and independence), physical problems (e.g., pain and symptoms), and education/information (e.g., lack of knowledge); breast cancer patients identified more unmet needs than other survivors [
9]. Furthermore, anxiety and symptoms of depression increase with the increasing incidence of cancer recurrence [
10]. When concerns outweigh necessity beliefs, nonadherence occurs according to the balance theory of the necessity-concerns framework [
11,
12]. Because many problems specific to MBC are left unanswered, patients with this disease frequently feel a sense of abandonment and isolation, including feelings of uncertainty [
13], a lack of control, and poor emotional functioning [
14]. With this background, patients with MBC are at risk of nonadherence to medication.
A systematic review on adherence-enhancing interventions for oral chemotherapy suggested that educational and consultation interventions are promising [
15]. The models of concordance and shared decision making have emerged as patient-centred approaches [
16]. In concordance, a therapeutic alliance is established between the healthcare professional and the patient through encouraging patients to discuss concerns about medications and preference for treatment and participation in decision making. Similarly, the patient and the healthcare professional share knowledge and experience on the available options to make a decision jointly in shared decision-making. As the needs of MBC patients vary greatly, care and support should be tailored to each individual patient, and the patients are encouraged to participate in the decision-making process [
4,
17]. It is critical for healthcare professionals to listen to and understand the patients’ concerns, beliefs, preferences, and expectations, and to confirm their understanding and commitment to the treatment [
18]. In terms of the patients’ control over medication management, healthcare professionals should focus on helping the patients uncover important issues, set a goal, and solve any problems [
19].
The importance of an individualised approach specific to MBC and respecting the patient’s preferences is emphasised in the international consensus guidelines for advanced breast cancer [
3]. Although the subjects of the study were not MBC patients, positive results were reported concerning the effect of patient preference-based interventions on adherence [
20] and outcomes [
21]. A systematic review of quantitative and qualitative studies revealed that providing written information only is not useful; patients do not value written information about medication and do not want this type of information as a substitute for discussion [
22]. Teach-back has been used as an educational strategy for patients with chronic disease. This involves asking patients to repeat the key points of a topic or instruction to ensure their understanding of the information provided by the healthcare professionals [
23]. This process helps motivate patients to adhere to medication and self-management [
24].
With the increase in oral therapies, nurses need to spend more time focusing on patients’ adherence to medication [
25] by providing proactive care [
26]. Nurses play an important role in educating patients about their treatment and the management of side effects [
27], monitoring adherence by identifying potential barriers and implementing intervention strategies [
28], and helping patients recognise when to seek professional help [
25]. Compared with adherence to hormone therapy in cancer patients [
29‐
33], adherence to oral chemotherapy and targeted therapy is a relatively new area of research. Two studies have reported the significance of nurse intervention, over the telephone in improving adherence to oral chemotherapy; however, one was a feasibility study and the other was a randomised study with a small sample size [
34,
35]. Spoelstra et al. [
36] suggested the importance of patient education provided by nurses for promoting adherence and managing symptoms. The effect of an intensified pharmaceutical care, including patient education and consultation, has also been reported for the improvement of adherence to capecitabine chemotherapy in patients with breast or colorectal cancer [
37].
Few studies have reported on interventions to improve adherence to oral chemotherapy; moreover, studies about oral chemotherapy specific to patients with MBC are rare. The current study focuses on adherence to oral chemotherapy and targeted therapy in an MBC population. We will highlight teach-back, goal setting based on patient preferences, and problem solving through follow-up counselling by nurses under the concept of concordance and shared decision making. We will also conduct a prospective randomised controlled trial on patient-centred intervention to facilitate medication management in MBC patients at three cancer centres in Japan. We will also perform qualitative evaluations on the programme based on the perceptions of intervention nurses.
Objectives
The objectives of this study are to determine the effects of a patient-centred medication self-management support programme in patients with MBC undergoing oral anticancer treatment, and to evaluate the programme’s effectiveness based on the perceptions of intervention nurses. We hypothesize that the intervention group will have a medication possession ratio (MPR) ≥90 % that is significantly higher than that of the control group.
Discussion
The present study will be the first Japanese study to evaluate the effects of a medication self-management support programme on patients with MBC undergoing chemotherapy or targeted therapy. It is characterized by a unique patient-centred approach with the principles of concordance and shared decision-making. A partnership between the patient and the healthcare professional is important in order to facilitate sharing of knowledge and experience with each other to reach an agreement on treatment [
54]. Nurses will help patients understand information by using teach-back, set goals with the patients concerning medication management based on patients’ needs and preferences, and help patients solve problems through follow-up counselling.
This mixed-method approach will allow an in-depth understanding of the effects of the medication self-management support programme. In the first phase, the primary outcome in the quantitative study will be assessed by using both objective (MPR) and subjective (MMAS-8) measures. Enhanced patient adherence to medication due to the intervention may lead to positive effects, which will be measured by using a wide range of outcomes including self-efficacy, psychological distress, symptoms, and patient satisfaction. In the second phase, the study will adopt a qualitative evaluation by using content analysis, which will provide practical information from the perspectives of the intervention nurses. A training programme has been developed, and to minimise variability among interventionists, the intervention nurses will be trained on medication self-management of anticancer agents before the study. This programme will also be useful when the intervention is applied in the clinical setting.
It should be noted that performance bias might occur owing to the open-label design of this study. The nature of the study, however, allows for refinement of the intervention in practice. When a patient is aware that adherence is being evaluated, overestimation of adherence in the self-reporting method is a concern. Although the MPR is commonly used to measure adherence, it is only a representation for actual medication use; we do not know whether the medication is actually taken or not. The present study will be carried out at three cancer centres; therefore, further research is needed in other settings to assess generalizability.
As the number of patients undergoing oral chemotherapy continues to increase, there will be a growing need for evidence-based medication self-management support. The present study has the potential to facilitate medication management not only in patients with MBC, but also in those with other types of cancer. The proposed intervention enhances the role of nurses in supporting patients and can be integrated into clinical practice.
Competing interests
The authors declare that they have no competing interest.
Authors’ contributions
HK contributed to developing research conception, design and methods as well as drafting of this manuscript. KY contributed to development of research design and methods, and manuscript preparation. TY was involved in the sample size calculation and statistics. All authors read and approved the final manuscript.