With GPs recently updated on the prevention and early detection of breast cancer, debate about how to manage breast density has come under the spotlight once again.
By Cathy O’Leary
The statistics for breast cancer in Australia are sobering. Not only is it the most common cancer in women – responsible for more than 21,000 new cases a year – it is also the second leading cause of death.
The lifetime risk of the disease is now nudging one in seven for women by the age of 85 – compared to about one in 12 in the 1990s – and there has been an increase in cases in younger women.
While treatments for breast cancer have gone ahead in leaps and bounds, the stark rates of the disease highlight the urgent need for better prevention, and educator Dr Sandy Minck is part of the push to bring GPs up to speed.
The Brisbane-based doctor contributed to new breast cancer guidelines recently published by the Royal Australian College of GPs in its Australian Journal of General Practice.
An article by Dr Minck, who is a member of BreastScreen Queensland’s Clinical Standards and Excellence Committee, guides GPs on evidence-based strategies for breast cancer prevention.
“More than 75% of cases occur in patients over 50, but there has been a 10% increase among patients under 50 in the past 20 years, so breast cancer will be a concern for younger patients too,” she said.
Dr Minck is a strong advocate of personalised risk assessment and promotes advice about modifying the impact of lifestyle factors such as alcohol, obesity and physical inactivity.
She said that in higher risk women, two main categories of medication – selective oestrogen receptor modulators and aromatase inhibitors – could decrease breast cancer risk by 30-60%.
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“These are an effective risk-reducing strategy for patients who do
not want to undergo, or want to postpone, mastectomy,” she said.
“Risk-reducing surgery is an option for those at very high risk of developing breast cancer. This can be overwhelming, and GPs can support women to make their own informed decision based on their individual risk, values, circumstances and the potential benefits and risks of surgery.”
Breast density role
The latest RACGP breast cancer advice weighs into the ongoing debate about managing breast density – the proportion of fibroglandular tissue measured on a mammogram.
Dense breast tissue, like cancer, appears as white on a mammogram, making it hard to pick up cancer and potentially delaying diagnosis and resulting in more advanced cancers. It is also itself an independent risk factor for developing the disease.
Breast density is not related to breast size or the ‘breast aware’ message promoted to women because it cannot be determined by feel or touch.
About 10% of Australian women have extremely dense breasts and they are four to six times more likely to get breast cancer than those with fatty breasts.
The RACGP guidance concludes that while women with dense breasts are more likely to benefit from supplemental screening, there is not enough evidence to routinely recommend this.
But the issue of whether women who are found to have dense breasts during their mammograms should at least be notified of this information has recently gained more clarity.
In what many doctors regard as a significant shift in position, Australia’s government-funded BreastScreen service now recommends that women with dense breasts be advised in writing and encouraged to talk to their doctor.
RELATED: Calls for national approach to breast density reporting
Western Australia has long been acknowledged as a trailblazer in this area – having quietly introduced a similar policy more than 15 years ago.
Poorly understood
According to Australian research, most GPs know little about breast density.
A BMJ Open study looked at GPs’ understanding of breast density and the value of discussing it with their patients – and found poor knowledge overall.
There were also mixed views about the benefit of notifying patients of their breast density, with some GPs believing it would create unnecessary anxiety.
Dr Minck has her own back story, having undergone a risk-reducing mastectomy in 2023. At the time of her treatment, she spoke out publicly about the lack of information given to women about the significance of breast density.
She believes she survived because she sought out private breast imaging, later self-funding an MRI and a clinical genetic consultation which found a mutation.
Dr Minck argues that while mammograms do not prevent cancer, they are a vital tool in early detection which can alter the outcomes for patients.
She told Medical Forum she welcomed the recent position announcement by BreastScreen Australia, acknowledging WA was the first State to notify women found to have dense breasts, with South Australia, Victoria and New South Wales since adopting the policy.
“BreastScreen Australia currently has a policy and funding review, and we’re anxiously awaiting the report, but while previously it was really about your sex and your age, which are the two biggest risk factors for breast cancer, there’s been a huge amount of work going into risk stratification screening,” she said.
Personalised risk
“What I’m advocating for is increased awareness and education so that women understand the breast cancer risk factors, particularly the ones they can do something about like alcohol, which sadly is a significant one, yet many women are completely unaware of this.
“There are multiple risk factors, and the more women have that information and knowledge, the more they can work out with their health care professional what screening strategy is best for them.
“The current one-size-fits-all approach for breast screening fits no one.” Dr Minck said that while there was evidence that other screening technologies improved mortality, very long-term data was needed to prove this.
“But with all the women I speak to, it’s about more than death, there’s quality of life, and we all know that the earlier you pick up cancer the less aggressive options you need to treat it, and we are very successful at treating breast cancer.
“There are lot of trials overseas that show that MRI and contrast-enhanced mammography pick up many more cancers than mammography and even ultrasound.
“So, my argument would be not just taking breast density in isolation but doing a risk assessment and if someone is in the high-risk category and under the age of 60, they will meet the Medicare criteria for an MRI rebate.”
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Dr Minck said she went to many GP education events and every breast surgeon or a radiologist at them talked about breast density. It was something doctors had known about for 50 years, but some were more informed than others.
“That’s why I’ve been raising awareness and informing GPs and also educating women so they can talk to their GP, but it is hard to talk about all the risk factors in a 10-minute consultation.
“It’s not just about GPs saying to women you should drink less, it’s about making women more aware of the risks and promoting healthy lifestyle choices so that women are living their best life.”
Dr Minck said women should be encouraged to be ‘breast aware’ and know what their breasts usually look like and feel like so if they see a change they can get it looked at quickly.
“I’ve been critical of BreastScreen in the past for not reporting breast density, but we are fortunate to have that service, and if it takes on that role in education and health promotion there will be more trust and participation rates will increase,” she said.
“GPs are the part of the healthcare system that are most able to look at preventive interventions, because once you’re in the hospital system you’re sick, you’ve missed the boat.
“But I recognise it’s very challenging for GPs to manage everything, and for patients the out-of-pocket costs have gone up significantly and it’s harder to get in and see your GP so that means it’s becoming harder to access GPs and get this advice.”
She said that in the public system, BreastScreen WA had been the only one initially reporting breast density back to women, and then South Australia came on board in 2023 and NSW and Victoria had followed suit.
“But having BreastScreen Australia recommend it from a national perspective is important,” she said.
“We’re on the right track and things are improving, and the more we talk about it the more GPs will become aware and then women will become aware, so we’re on this pathway to hopefully having more personalised risk assessment and screening.
“And that may lead to more people being able to take advantage of risk-reducing medication or surgery if that’s what they want, but also early intervention.
“We do hear about overdiagnosis and overtreatment, and critics of mammography often bring up the so called ‘harms’ and I get quite upset when I hear that term because to me a harm is something really serious.
“And while having biopsies can be inconvenient, uncomfortable and expensive, if this is a person making an informed decision on what is best for them and how they want to proceed, it takes away from that whole view of ‘well if we can’t do it for everyone, then we can’t do it’.
“I think most women would prefer to be overdiagnosed than underdiagnosed.”
Calls for uniformity
Breast Cancer Network Australia also welcomed BreastScreen Australia’s new position on breast density, describing it as a significant step forward for transparency.
Director of policy, advocacy and support services Vicki Durston commended WA, South Australia, Victoria and New South Wales for leading the way, but called on Queensland, Tasmania, Northern Territory and the ACT to report breast density without delay.
“Every woman has the right to know her breast density and understand her breast cancer risk, and we need every state and territory to act now to provide this information, along with clear pathways for supporting women at higher risk,” Ms Durston said.
Dr Emmeline Lee, director of BreastScreen WA, said that in 2008 the WA service became the first breast cancer screening program in Australia to provide information on mammographic breast density to women screened, and notify those found to have dense breasts.
“While reporting breast density can enhance awareness and potentially lead to earlier detection through additional screening, the direct impact on saving lives is still a subject of ongoing research,” Dr Lee told Medical Forum.
“But having said that, I know of specific cases where informing a woman that she had dense breasts has led to her being seen by her GP for a consultation and clinical breast examination which found a lump that turned out to be a breast cancer that was hidden by the breast density on the mammogram.”
She said it was important for women to have information because mammographic breast density could make it harder to detect abnormalities on screening mammograms, potentially leading to delayed diagnoses.
Women with dense breasts also have a higher risk of developing breast cancer compared to those with less dense breasts, however, this did not necessarily translate to a higher risk of death from breast cancer.
Informing women about their breast density could lead to more personalised screening strategies for some women and awareness of risk factors for breast cancer.
Next steps
Dr Lee said that if women have dense breasts, BreastScreen WA recommends they see their GP for a consultation and clinical breast examination.
A recent study published in The Lancet found that offering additional scans to women with very dense breasts – contrast enhanced mammography (CEM), abbreviated magnetic resonance imaging (AB-MRI) and automated whole breast ultrasound (ABUS) could detect 3500 extra breast cancers a year in the UK.
The trial showed that CEM and
AB-MRI were particularly effective, detecting 17-19 cancers per 1000 women that were not seen in mammograms.
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But Dr Lee said there were a few points of concern, including the logistical challenges of implementing additional scans like AB-MRI and CEM into routine practice because of limited availability of MRI scanners and the need for contrast agents, particularly in big jurisdictions like WA where more than “10 UKs could fit into our State”.
Other issues were cost and accessibility, false positives and overdiagnosis, and rare adverse reactions to the contrast agents in CEM.
Dr Lee said more research was needed to confirm whether additional scans would reduce the number of deaths, as cancers detected through screening were not always life-threatening.
“GPs have a crucial role in breast cancer detection, from ensuring eligible patients have their regular screening mammograms with BSWA to following an appropriate assessment strategy such as the Triple Test to investigate a new breast symptom,” she said.
“Women and their GPs might benefit in considering using iPrevent and CanRisk – online tools that enable the calculation of an individual’s future risks of developing breast cancer using cancer family history, genetic and other risk factors.
“By combining regular mammograms with these additional strategies and the support of their GPs, women can significantly enhance their chances of early cancer detection.”
Dr Lee said WA had a well-established multidisciplinary group of breast specialists to support GPs looking after their patients with breast issues.
No ‘best’ approach
Dr Minck said that when it came to supplementary screening such as MRI or contrast-enhancing mammography, her view was that there was no ‘best’.
“It’s about what is going to work depending on your circumstance, and MRI is not going to work if you’re in a remote area and you have to travel thousands of kilometres,” she said.
“It’s about saying here are the options and the advantages and disadvantages and letting women and their GPs make that choice.
“We’re moving in the right direction, and it’s a big move by BreastScreen Australia, which has listened to patient advocates and consumers, and that is fabulous.
“Ultimately awareness is the first step, so women should be encouraged to discuss any family history of breast cancer with their GP, become familiar with the normal look and feel of their breasts, and promptly speak to their GP about any new or unusual changes.”
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