This study provides insight into awareness and knowledge about breast density among women in Australia. The findings reveal a significant deficit in fundamental knowledge of breast density, even though many of the participants were familiar with the term ‘breast density’. Moreover, women were largely unaware that breast density is a risk factor for breast cancer, despite many possessing knowledge about the masking effect. This study elucidates the factors that contribute to increased breast density knowledge, including younger age, English language spoken at home, prior breast density notification, and breast density awareness.
With ongoing discussion both in Australia and internationally as to the need for notification of breast density, this study highlights the informational needs of women to support accurate knowledge of breast density and the high degree of preference for knowing such information. Notably, South Australia is the second state in Australia, following Western Australia, to implement breast density notification as an integral component of the population-based screening program (3, 20, 21, 25). The Australian context differs from the United States, given that, by April 2015, a total of 22 states had enacted legislation mandating to notify women about breast density (27). Likewise, information pertaining to breast density is distributed across the six jurisdictions in Canada in a comprehensive manner. Among them, five inform specifically women classified under category D directly, while one provides information to their respective physicians (28). As notification by BreastScreen South Australia commenced after the closing of the current study, it is worth mentioning that the study cohort have not been generally exposed to density notification at the screening program before participating here.
Regarding awareness among the study cohort, 60% of respondents had heard the term 'breast density' before. The level of awareness among South Australian women is notably lower compared to Western Australian women (> 80%), where breast density notification has been more widespread (24).
The questionnaire revealed that approximately one-quarter of the study cohort had been notified of their own breast density, a finding that aligns with the results of a prior study conducted in the United States during a period when breast density notification was not mandated by legislation (29). Less than 60% of participants correctly answered two or more questions out of five about breast density. These findings underscore a fundamental knowledge deficit about breast density among Australian women.
At the same time, awareness of breast density was a predictor of knowledge, suggesting that efforts in Australia to raise awareness have had an impact on knowledge. Similar findings were observed in a recent study conducted in Croatia (30). This is in contrast with recent studies conducted in the United States. Variables including education, screening history, and preferred language were found to play a role in disparities in awareness but did not exert significant impact on knowledge levels (31). Another US study reported that density notification may increase overall awareness; however, may not have a discernible impact on increasing knowledge concerning the masking effect and the risk associated with breast cancer (32). Further research is required to establish optimal approaches for raising awareness about breast density that lead to increased knowledge.
In the current investigation, only 23% of women were aware that high breast density is a risk factor for breast cancer. This figure is nearly three times lower than that reported in a prior U.S. study, where breast density notification is mandated by law (33). A European study suggests that awareness of breast cancer risk can have a favourable impact on breast screening rates (30). Considering these findings, it is imperative to devise strategies for enhancing this important knowledge among women, aiming to promote greater participation in healthy lifestyles, breast awareness and screening programs.
Several states within the United States have demonstrated positive outcomes by incorporating breast density notification into their population-based screening programs, leading to enhanced knowledge and awareness of breast density among women and increased participation in subsequent screening (33). However, the exclusion of breast density information in breast cancer screening in Australia is viewed by consumers as failing to adequately address women’s 'right to know' and the enablement of their involvement in shared decision-making processes (3, 34). Interestingly, irrespective of awareness and knowledge status, eighty-two percent of the respondents indicated a desire to ascertain their individual breast density, regardless of their level of awareness. This outcome is similar to the results observed in the pilot study conducted by BreastScreen South Australia (25).
Regrettably, there exists the risk of common misconceptions that may taint genuine knowledge. Common misconceptions regarding breast density, such as the belief that it can be diagnosed through touch or is associated with breast size, are prevalent. Notably, the current study identifies the key predictors dispelling these prevalent misconceptions among women. In this context, both prior breast density notification and breast density awareness play pivotal roles. While the current study suggests that awareness and notification is associated with increased knowledge about breast density, more communication is required to comprehensively dispel common misconceptions. Websites (35) and factsheets (36) that provide breast density information should be aware of these common misconceptions and actively seek to dispel them. For the most comprehensive information, personalised counselling within a dedicated radiologist-run breast density consultation may foster better understanding among women about breast density and augment their participation in shared decision-making (37).
However, radiologist consultation regarding breast density is not practical within population-based breast screening. The inclusion of general practitioners (GPs) and breast care nurses in this context could afford a more cost-effective and efficient support system for women with dense breasts. Given the inherent diversity in women's knowledge levels and individual risk, we posit that personalised, one-on-one consultations is preferred, as a 'one size fits all' approach may not suffice. Given the limited understanding of mammographic density among Australian GPs (38), it is also imperative to explore approaches for enhancing their education and training. Well-structured and comprehensive training to GPs and breast care nurses could empower them with the requisite knowledge and competencies to guide women about critical information concerning breast density. This approach would empower women to be actively involved in making decisions on how best to manage their breast cancer risk and breast cancer screening in line with the National Women’s Health Strategy 2020–2030 of Australia (39) and Women’s Health Strategy for England 2022 (40).
This study addresses critical gaps within the extant literature, notwithstanding certain limitations. We enrolled women from a single centre and generalisability may be limited. Moreover, we did not collect data on the literacy status of women, despite its considerable influence on breast density awareness status (31). Another constraint is our inability to elucidate the reasons for study non-participation among non-respondent women. It is plausible to speculate that non-participation might be influenced by factors such as coming from culturally and linguistically diverse (CALD) backgrounds and the need for interpreters for clinical appointments. The proportion of participation of women coming from CALD backgrounds was lower than the expected population from The Queen Elizabeth Hospital catchment area. A drawback of this kind of questionnaire for non-English speaking participants is the reliance on hospital interpreters, whose principal role is assisting patients in the context of their clinical consultation, not completing a research questionnaire. Interestingly, the majority of responses we received from CALD participants were when a family member proficient in English was present to assist, rather than a professional interpreter. To increase participation in women from CALD backgrounds, the study questionnaire should be translated into different languages.
The primary merit of this study is its capacity to discriminatively pinpoint influential predictors of common factual knowledge and misconceptions about breast density. Another notable strength of this study is its high response rate of 82%, which exceeds that of prior studies with similar (29) and even larger cohorts (24, 33).