Background
Breast cancer is the most common malignant disease in women worldwide. Despite the progress of research and treatment, up to 30% of the patients afflicted by breast cancer will still develop metastases [
1]. With the occurrence of metastases, not only the patients’ life circumstances but also therapeutic approaches change substantially as metastatic breast cancer (MBC) is not yet curable. Prolonging survival and maintaining the best possible quality of life (QoL) by controlling cancer progression and minimising side effects become the leading treatment goals. Fortunately, the overall survival has increased over the last 20 years due to improved treatment options. While the median overall survival was 21 months in 1990, it has been rising steadily to 38 months in 2010 [
2]. With an average survival of 38 months and 18,570 annual deaths [
3], it can be assumed that currently, more than 60,000 women affected by MBC are living in Germany. The appropriate treatment of these women is still a challenge from a medical, psychosocial and economical point of view. While the disease progresses, the probability of a therapeutic response decreases with each further treatment—it can be less than 15% among previously treated patients [
4]. Enormous psychological strain and emotional burden on the patient require extensive support and preventive measures [
5]. Furthermore, the treatment costs of advanced breast cancer are currently estimated at about 100,000 US dollars per patient, per year [
6,
7]. The aforementioned complexity is a high burden for patients and their treating health care providers and showcases the need to develop new approaches of health care delivery.
One possible approach to optimise overall survival and quality of life is the use of patient-reported outcomes (PROs). Physicians often underestimate the challenge of assessing the severity of symptoms or therapy side effects [
8‐
10]. This particularly concerns unspecific symptoms such as appetite loss and fatigue, although these might indicate disease progression [
11]. Electronic PROs deliver real-time data about the patients’ general condition without interpretation by an intermediate authority (i.e. the treating physician) [
12] and may detect disease progression and therapy side effects, respectively, at an early stage. Acute disease-related burden can thus be identified with low personnel effort by using mobile devices. In a landmark monocentric study involving 766 patients, Basch et al. were able to show that an intensified PRO monitoring of metastatic cancer patients can lead to an improvement in QoL and to a reduction of unplanned hospitalisations and emergency room visits [
13]. Furthermore, it also led to a statistically significant increase in survival [
14]. Similar effects regarding the positive impact of an intensified PRO monitoring on survival were shown in a study by Denis et al. increasing the overall survival from 13.5 to 22.5 months in the monitoring group [
15]. Müller et al. showed that disease progression is associated with deterioration of health-related quality of life (HRQoL) in patients with MBC [
16]. Therefore, early detection of a decrease in HRQoL, which possibly indicates tumour progression, might spare patients treatment cycles with a no longer effective therapy.
With PRO B, we want to investigate whether the benefits of PRO monitoring are transferable from a monocentric study setting into German routine care and if the above-discussed findings can also be shown in breast cancer patients. Therefore, the structure of the project is designed to include all types of care providers in Germany. We will recruit up to 40 breast cancer centres at hospitals in rural and urban areas as well as university hospitals. To facilitate implementation, we will use the existing structures within the network of breast cancer centres certified by the Deutsche Krebsgesellschaft e.V. (DKG, German Cancer Society). Currently, 80.3% of all newly diagnosed breast cancer patients in Germany are treated at a breast cancer centre certified by DKG [
17]. In order to obtain certification, every centre has to report structural, processual and outcome data which are audited annually. During PRO B, the data transfer will be conducted by OnkoZert’s IT-tool OncoBox. OncoBox, as implemented in the electronic case report form (PRO B Doc), will enable the connection of clinical and PRO data through an interface of the participating breast cancer centres’ study-specific documentation and a connected smartphone application for the PRO collection.
To our knowledge, this is the first multicentre randomised controlled trial to investigate the effects of PRO in clinical practice on HRQoL and survival exclusively among MBC patients.
Discussion
Within the PRO B intervention group, we expect the QoL to be improved and unplanned hospitalisations, emergency room visits as well as treatment costs to be reduced through early detection of decreasing QoL.
In case of positive results, our approach would allow a fast and easy transfer into clinical practice due to the use of the already nationwide existing IT infrastructure of the German Cancer Society (DKG) and OnkoZert.
We recently implemented electronic PROs in the adjuvant setting at our own institution and recognised a high acceptance and response rate among all age groups [
27]. Up until now, PRO measurement is not standardised and did not yet reach clinical practice throughout the country. With PRO B, a first step towards a nationwide, comprehensive, standardised, affordable and easy collection of PRO data will be done, possibly enabling a better assessment of the consequences of breast cancer treatment and its related implications on the patients’ quality of life. This information could be of great value in the counselling and decision-making processes for both practitioners and patients with metastatic breast cancer.
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