Background and rationale {6a}
In Germany, around 70,000 women are diagnosed with breast cancer every year. An additional 7,200 women are diagnosed with ovarian cancer [
1]. Approximately 30% of these new diagnoses have a family history of these cancers, a quarter of which are due to a pathological gene mutation in either the breast cancer type 1 or type 2 susceptibility genes (
BRCA1 and
BRCA2, respectively
).
BRCA1 and
BRCA2 genes are tumor suppressor genes that produce proteins which are responsible for repairing DNA [
2]. A mutation in either of these two genes has been found to significantly increase the risk of breast and ovarian cancer development, with an approximately 72% (95% confidence interval (CI) 65–79) or 69% (95% CI 61–77) cumulative lifetime risk (up to the age of 80 years) for breast cancer for
BRCA1 or
BRCA2 mutation carriers, respectively.
BRCA1 mutation carriers seem to be affected slightly more often and at a younger age than
BRCA2 mutation carriers. The cumulative lifetime risk for ovarian cancer is 44% (95% CI 36–53) for
BRCA1 and 17% (95% CI 11–25) for
BRCA2 mutation carriers [
3]. In comparison, the lifetime risk for breast cancer in the general population is roughly 13%, while the risk for ovarian cancer is around 1%.
Several familial indications suggest genetic testing for healthy women, such as having two or more women with either breast or ovarian cancer, or having one woman with both cancers, or having only one woman with breast cancer who was younger than 36 years at diagnosis [
4].
These differences in cancer risk and age at onset display the complexity of the genetic counseling provided for healthy
BRCA1/2 mutation carriers. In order to deal with the increased risk of developing cancer, healthy mutation carriers can choose between different options to reduce cancer incidence and mortality. The options are an intensified breast cancer-screening regimen, which includes biannual to annual magnetic resonance imaging (MRI) and mammography as well as semi-annual ultrasound examination, or prophylactic surgeries, such as bilateral mastectomy and/or salpingo-oophorectomy. While the intensified breast cancer screening does not reduce the likelihood of developing cancer, it detects breast cancers in stage 0 (carcinoma in situ) or stage 1 in approximately 80% of cases [
5,
6]. However, there is a remaining risk of detecting cancer too late for effective treatment. In addition, particularly women with a
BRCA1 mutation develop triple-negative breast cancers in 75% of cases [
7], meaning there is no expression of estrogen, progesterone, or human epidermal growth factor receptors [
8]. These breast cancers require chemotherapy and are usually associated with poor prognosis [
7,
8].
By contrast, women who have undergone risk-reducing bilateral mastectomies have been found to significantly reduce their breast cancer risk to a remaining risk of 5% on average [
9]. One study reported that women with intact ovaries reduce their breast cancer risk through bilateral mastectomy by 90%, while women who had prior salpingo-oophorectomies reduced their risk by 95% [
10], indicating that salpingo-oophorectomies have an impact on breast cancer risk. In fact, one study confirmed that salpingo-oophorectomies do indeed reduce breast cancer risk when performed premenopausally [
11]. Additionally, salpingo-oophorectomies have been associated with an 80–90% reduction of ovarian cancer [
12]. Some women decide to not take any action to deal with their individual cancer risk, in which case the lifetime risk remains unaffected.
For
BRCA1/2 mutation carriers, the decision between prophylactic surgeries and/or joining the screening program is based upon age of the woman, memories of family cancers, fertility and desire to have children, caring for children, close relationships, body image, ongoing risk and survival, among others [
13‐
17]. For example, in one study, over a third of women who had undergone prophylactic mastectomy reported a decrease in their level of body satisfaction [
17]. The same women showed significant decreases in their emotional concern about developing breast cancer. In case of the screening program, about 10% of MRI examinations result in unclear findings and require further imaging and examination [
6]. This often results in high levels of anxiety in women [
18] even though the majority (75%) of the results turn out non-cancerous [
6,
19].
The examples above show the significant difficulty which healthy women with a
BRCA1/2 gene mutation face when encountering their breast cancer risk. Previous research with breast cancer patients has shown that the majority of patients prefer to be involved in medical-decision making [
20,
21]. Not addressing these preferences can result in increased anxiety and decreased satisfaction [
22]. In an international sample of breast cancer patients, Brown and colleagues [
21] showed that while roughly 63% of patients prefer patient-centered or shared decision-making pre-consultation, only 54% experienced the decision-making as such, while 46% experienced the consultation as being “oncologist directed”. Furthermore the study showed that patients who were as involved as they anticipated, or received an even more patient-centered approach than they anticipated, reported higher satisfaction with the decision-making process, lower levels of decisional conflict, as well as greater satisfaction with the decision. This shows that patients should be actively involved in medical decision-making. The German Federal Ministry of Health picked up these findings and included them in the National Cancer Plan guideline, which now lists providing evidence-based patient information as well as patient involvement in medical decision-making as two of its goals [
23]. Additionally, the German patient’s rights act and the German medical treatment guideline for breast cancer confirmed the patient’s rights of participation and informed decision-making. Informed decision-making implies that women are enabled to make their choices based on adequate knowledge about existing options and in congruence with their individual preferences [
24,
25].
Two ways in which these goals can be accomplished in situations where more than one treatment option is available are evidence-based patient decision aids or decision coaching programs. Decision aids are evidence-based patient information that may be delivered in a variety of forms, such as web-based, paper-based, or video-based [
26]. They have been shown to increase patients’ knowledge about treatment options, improve risk perception and support value-based, active decision-making [
26]. Usually, they are used to supplement the physicians’ consultation since patients are often too overwhelmed by the diagnoses to fully absorb all information presented [
27].
Decision coaching on the other hand refers to a consultation with a trained health-care professional in which all treatment options are discussed in a non-directive manner [
28]. This exchange helps the patient to thoroughly understand the risks and benefits associated with each treatment decision, evaluate decisional needs, assess important personal values for the decision, as well as acquire strategies to communicate a decision to the physician to facilitate shared decision-making [
28]. Decision coaching may vary by form (face-to-face, telephone call, or video call) or by person providing it (psychologist, nurse, pharmacist, social worker, or counselor among others). The person providing the decision coaching (decision coach) should be qualified in decision support and have sufficient expertise in the field of the decision. Additionally, contextual knowledge of the clinical surroundings simplifies the coordination with the physician after the decision coaching. Green and colleagues [
29] showed that decision coaching could significantly improve knowledge about treatment options compared to usual care.
Both forms of decision support (decision aid and decision coaching) are often combined, for example, when the decision coach offers a decision aid as the basis of the decision coaching [
30,
31]. In a systematic review significant differences were found regarding the outcomes knowledge about treatment options, perceived participation in decision-making, satisfaction with the decision-making process between the intervention group (IG; decision coaching and decision aid) and the usual care control group (CG) [
26]. Moreover, in a trial that compared decision coaching combined with a decision aid with decision aid alone, patients who also received the decision coaching experienced a more active role in the decision-making process [
32].
Internationally, only a few studies have explored decision support for
BRCA1/2-positive women without breast cancer. One recent study pilot tested a paper-based decision aid and found it was well accepted by affected women as well was experts [
33]. A randomized controlled trial (RCT) testing the effectiveness of a decision aid recruited women up to one month after receiving a positive
BRCA1/2 test result and were followed for 12 months [
34]. It was found that women receiving the decision aid had significantly lower cancer-related distress at 6 and 12 months compared to the CG. Decision coaching has not yet been applied in
BRCA1/2-positive women. However, a recent German study has shown that the extent of patient participation in treatment decision making was significantly higher in women with ductal carcinoma in situ who received nurse-led decision coaching combined with an evidence-based decision aid compared to standard care. In addition, only women in the IG made informed choices [
35]. Despite these promising findings, decision support programs have not been systematically implemented in Germany. This study protocol describes a RCT evaluating structured decision support consisting of a decision aid and decision coaching for
BRCA1/2-positive women with no prior history of breast or ovarian cancer.