Australian General Practitioners’ Current Knowledge, Understanding, and Feelings Regarding Breast Density Information and Notification: A Cross-Sectional Study

Background: There is a lack of evidence around Australian general practitioners’ (GPs) views of issues surrounding breast density. The current study aimed to quantitatively assess GPs’ current knowledge, understanding, and feelings around breast density information and notification. Methods: This study involved a cross-sectional survey using an online platform to collect quantitative data from Australian GPs. Survey data were analysed with descriptive statistics. Results: A total 60 responses from GPs were analysed. Most (n = 58; 97%) had heard or read about breast density and nearly 90% (n = 52; 87%) have had discussions about breast density with patients. Three-quarters (n = 45; 75%) were supportive of making breast density notification mandatory for patients with dense tissue and a similar proportion (n = 45/58; 78%) felt they need or want more education on breast density. Conclusions: There is strong support for notifying patients of breast density, and interest in further education and training among the surveyed GPs. As GPs play a central role in cancer prevention and control, their involvement in discussions related to breast density notification, evaluation and appraisal of evidence, development of communication strategies, and participation in ongoing research on the topic will be indispensable.


Introduction
Breast density is an independent risk factor for developing breast cancer [1]. A density level (entirely fatty, scattered areas of fibroglandual density, heterogeneously dense, or extremely dense) is usually determined by radiologists using mammography [2]. As mammography uses X-ray, the more dense a tissue is, the whiter it appears, hence denser breast tissue can 'white-out' or obscure a cancerous lesion, which also appear white. Mammography has been associated with lower sensitivity in detecting breast cancer in individuals with denser breast tissue, and an increased risk of breast cancer diagnosis between routine screening intervals [3,4].
Breast density is a relatively non-modifiable risk factor. Currently, there are no uniformly recommended treatment or prevention options related to breast density [5]. Supplemental screening, such as offering ultrasound or MRI in addition to mammography, may be offered to women with dense breasts to increase screening sensitivity. However, the evidence surrounding the benefits and harms of supplemental screening remains unclear. Supplemental screening may increase cancer detection rates; however, it can increase the rates of false-positive results, potentially leading to overdiagnosis and overtreatment [6]. Furthermore, there is still uncertainty around whether supplemental screening improves long-term health outcomes, including the breast cancer mortality rate.
Recently, there has been discussion about whether population-based screening program participants should be notified of their breast density. Much of this debate is around the potential benefits and harms of notification, including health system effects, clinical outcomes, aspects of medical decision-making, and individual psychological and wellbeing impact. The United States (US) Congress recently passed legislation requiring mammography facilities to inform individuals, and their physicians, of their breast density level [7]. To date, no other country has legislated mandated notification of breast density.
Currently, breast density is neither measured nor reported in the Australian publicly funded breast screening program (BreastScreen Australia), with the exception of BreastScreen WA. Having undertaken recent evidence reviews, BreastScreen Australia's Standing Committee on Screening recommended that breast density should not be routinely recorded [8,9]. It also recommends that, given the uncertainties in the measurement and management of breast density, patients with dense breasts not be offered supplemental screening (BreastScreen Australia 2016, 2020). However, BreastScreen Australia also noted in the statement that it will continue to engage key stakeholders in developing an evidence base and potentially piloting notification [8,9]. There have been consumer groups advocating for breast density notification, and some women have already been being notified through private screening services.
In Australia, quantitative evidence on the impact of breast density information and notification for primary care practitioners is lacking, despite heightened debate around breast density notification. General practitioners (GPs) are at the forefront of primary and secondary prevention of breast cancer in Australia and are likely to become a first point-of-contact for patients who are informed of, or are concerned about, their breast density. Therefore, the current study aimed to quantitatively assess Australian GP's current knowledge, experience/practice, and attitudes around breast density information and notification.

Design
This is a cross-sectional online survey study. Ethical approval was granted by the [* blinded for review].

Sample and Recruitment
GPs were recruited through several avenues, including (1) an email, with the participant information statement (PIS) attached, to the Royal Australian College of General Practitioners Breast Medicine Special Interest Group mailing list; (2) an email, with PIS attached, to a list of GPs who had consented to be contacted for future studies after participating in previous University of Sydney research; and (3) a brief study advert on the 'GPs DownUnder' and 'GP Mums (AUS/NZ)' Facebook group pages, which together have more than 10,000 active GP members. We also contacted all 31 primary health networks across Australia and received permission or confirmation from nine of them to advertise either through their website or newsletters. All avenues included study investigators' details and a link to the survey landing page on the Qualtrics online platform [10]. The survey landing page included brief information about the study along with the PIS and participant consent form (PCF) for downloading and viewing. Each participant was offered a chance to enter a prize draw to win one of five gift vouchers ($A100 each).

Data Collection
The questionnaire consisted of measurement scales and items adapted from previously published literature [11][12][13][14] and self-developed items based on our previous qualitative study findings (see Supplementary File S1: Survey for primary care clinicians (GPs)). The questionnaire was divided into five sections: (1) GP characteristics; (2) knowledge of breast density, where those with self-identified knowledge of breast density were asked further questions about the source of the knowledge, and regarding breast density measurement, association with cancer risk and age, impact on mammogram reading, and supplemental screening (GPs who had indicated no prior knowledge of breast density skipped to section four); (3) prior experience and practices in discussing breast density with women (the term woman is used to include all people who have experienced oestrogen dependent breast tissue development); (4) attitudes and views towards notification, where GPs were provided with a short synopsis of the current evidence surrounding breast density and the current landscape of notification in Australia and overseas; and (5) the need for future GP education and training, as well as suggestions. The online survey was open for data collection from May to November 2021.

Data Analysis
Data were descriptively analysed using SPSS version 24 [15]. Frequency and relative frequency were used to summarise binary and categorical variables. Continuous variables are reported using means and standard deviations.

Participant Characteristics
Sixty valid and near-complete (progress ≥ 80%) responses were received. Of the GPs who participated, 45 (75%) worked exclusively in private practices, 40 (69%) practiced in major cities, 54 (90%) were female, half had been working in general practice for less than 10 years, and 22 (37%) had a special interest in women's health or breast health (Table 1).

Knowledge about Breast Density
Most of the GPs (n = 58; 97%) had heard or read about breast density prior to taking the survey. For those who had prior knowledge, 'reading the mammogram reports' was the most common source for having heard or read about breast density (n = 43; 74%), followed by 'talking to colleagues or other clinicians', and 'reading journal articles or other professional reading materials' (both n = 27; 47%). GPs self-rated their understanding of breast density on a five-point Likert scale and the mean score was 3.3 (range 2-5, standard deviation 0.85), indicating an average level of understanding. The majority of GPs correctly identified how breast density was measured (n = 48; 83% for mammogram); one-fifth (n = 13; 22%) incorrectly identified physical examination of breasts. More than half of the GPs were aware of increased breast cancer risk associated with density (n = 36; 62%); risk of dense breast tissue masking cancer on mammography (n = 53; 91%); decrease in breast density with age (n = 48; 83%); and the concept of supplemental screening (n = 42; 72%) (see Table 2).

Prior Experiences and Practices
Among 58 GPs who reported having prior knowledge of breast density, almost 40% (n = 23) reported having discussions with patients about breast density around once a month, and 22.4% (n = 13) reported having a discussion once a year (see Table 3). About 10% (n = 6) reported having never discussed breast density with a patient for various reasons, including having never seen it reported on mammogram reports. Of those who had discussed breast density with patients (n = 52), most were very (n = 16; 31%) or somewhat (n = 26; 50%) comfortable with answering patients' questions about breast density. More than half of the GPs with self-identified knowledge regarding breast density (n = 28; 54%) reported offering supplemental screening to only certain patients with dense breast tissue, depending on risk factors or on recommendations from the mammography report.

Views towards Notification
Three quarters (n = 45; 75%) of all GP respondents were supportive of the notion of making breast density notification mandatory for patients with dense tissue (see Table 4). Most agreed that notifying patients will promote informed decision making (n = 44; 76%) and were in favour of notifying via mammogram results (n = 46; 79%). The GPs agreed or strongly agreed with the suggestion that counselling patients about breast density is primarily their responsibility as a GP (n = 40; 69%), and that patients have a right to know about their breast density (n = 53; 91%). Half of the GPs (n = 30; 52%) agreed/strongly agreed that notification might cause patients undue anxiety. Almost 70% (n = 40) agreed/strongly agreed that a policy of routine and widespread notification of breast density to patients would impact their clinical practice, and a similar proportion (n = 39; 67%) felt they were prepared to respond to requests from patients. Most GPs thought that statements to be added to the breast density notification letter sent to patients should include "additional screening may be advisable" (n = 44; 76%) and "the patient should discuss results with their primary care physician or the referring physician" (n = 48; 83%).  a Only those who had no experience in discussing breast density were analysed for this item. b Only those who had experience in discussing breast density were analysed for the subsequent items. c Only those who recommend supplemental screening were analysed for the subsequent items. d Only those who had no experience in discussing breast density were analysed for this item.

Future Information Provision and Training
More than three-quarters of GPs (n = 45/57, 79%) felt they need or want more education on breast density. They felt the most useful options to increase their knowledge would be synopsis of up-to-date scientific evidence (n = 40, 70%), informational pamphlets/materials for patients (n = 40, 70%), and professional college educational programs (n = 37, 65%). Conferences or workshops (n = 22, 39%) and interdisciplinary discussions with radiology departments (n = 16, 28%) were also noted as useful educational options to alleviate confusion and improve the counselling process.

Discussion
This cross-sectional survey of Australian GPs shows that, despite a high level of awareness of breast density as an issue, there is still a lack of knowledge around its clinical significance and evidence-based supplemental screening options. Most GPs reported experience of discussing breast density with patients, although with substantial varying frequency. There was strong support for breast density notification, with three in four GPs supporting an Australian mandatory reporting policy. Importantly, over 82% of GPs believed that they were the appropriate clinicians to discuss breast density with patients, with the majority indicating they would need more education on the topic.
Nickel et al. previously conducted a qualitative study into the views and perception of Australian GPs regarding breast density and potential notification [16]. The findings from this study pointed to GPs' limited knowledge about breast density and mixed views towards notification, especially when clear guidelines in managing breast density are lacking [17]. The findings from the current study, however, indicate a higher level of knowledge and support for notification. This could be because of a high proportion of GPs in the current study having a specific interest in breast or women's health. When compared with a similar cross-sectional study of primary care clinicians from Massachusetts, United States, where there is mandated notification, a higher proportion of Australian GPs held positive attitudes towards informing patients of their breast density (38% vs. 79.3%), believed it would promote informed-decision making (25% vs. 75.9%), and regarded counselling as their responsibility (43% vs. 68.9%) [13]. Again, these results need to be interpreted in light of our sample characteristics and differences in health systems. Compared with physicians in another survey study from the Mayo Clinic in the United States, GPs in our study had a similar comfort level in discussing breast density with patients (around 80%), yet were less likely to offer supplemental screening based on individual risk assessment (47% vs. 26.9%) [12]. Our findings demonstrate that country-level variation in attitudes and views exists, and Australian GPs in the current study tend to be more positive about breast density notification. However, given the limitations noted below, to draw a more definitive conclusion, more research is needed. Regardless, even among this group of GPs who had self-selected to participate in the current study and had a higher level of awareness or experiences with breast-density-related issues, the interest and need for further education and training is clear. This is in line with our earlier qualitative study findings [16]. This highlights the need for widespread education campaigns, especially if breast density notification is to be introduced through BreastScreen programs.
Despite our efforts to recruit GPs from multiple channels and maximise the sample size, because survey sampling happened during the COVID-19 pandemic, for which GPs were at the frontline, we were only able achieve a small sample size. This has limited our analysis to be only descriptive. We also had a high proportion of GPs (35%) who had a special interest in women's or breast health. GPs who decided to take part in the study might be more aware of or interested in topics relating to breast density than those who did not. Therefore, although the survey was open to all Australian GPs, the study findings may not be generalisable. Future studies with a larger and more representative sample size are warranted.

Conclusions
This paper provides a descriptive analysis of data collected from a small group of GPs in Australia regarding their knowledge, attitudes, and views about breast density and its potential notification for patients. The results are promising in terms of awareness and knowledge, and there is strong support for notifying patients of breast density, as well as interest in education and training in the subject area. Breast density has gained increased attention from policy-makers, practitioners, and consumer advocates in recent years and will continue to attract discussions with increasing evidence surrounding it. As GPs play a central role in cancer prevention and control, their involvement in discussions related to density notification, evaluation and appraisal of evidence, development of communication strategies, and participation in ongoing research on the topic will be indispensable.