When Krysty Sullivan had a routine mammogram in 2019, she was given the all-clear.
Eleven months later, she felt a lump.
Doctors discovered two tumours, each more than 2cm in size. Sullivan, then 48 years old, was diagnosed with triple-negative breast cancer, a type that can be challenging to treat as the cancer cells do not respond to typical targeted treatments.
“It’s always a shock to hear that you have breast cancer, but to learn that I had it months after I had a clear mammogram … it was like the Earth shifted,” Sullivan said. “I was left wondering what I had missed.”
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Sullivan was not told after her mammogram screening that she has the highest category of breast density (known as Bi-rads D), meaning she has very little fatty tissue. This significantly lowers the sensitivity of a mammogram, making it harder to see small abnormalities such as cancers. She was not told at her screening that dense breasts (classified as Bi-rads C or D) also slightly increase breast cancer risk.
Sullivan went on to have a double mastectomy and 16 rounds of chemotherapy. Doctors told her it is likely her cancers were present during her mammogram, but not detected due to her breast density.
New national guidelines for GPs released by the federal health department on Thursday say patients like Sullivan should be informed if a mammogram shows that they have dense breasts, and their GPs should be given additional guidance about how to respond. For someone with Bi-rads D, the guidelines say additional imaging should be considered.
The guidelines advise GPs to ask women with high breast density about other risk factors such as familial history to further calculate breast cancer risk and, depending on the risk level, women with high breast density might be offered additional screening covered by Medicare.
Dr Anna Withanage Dona, a research fellow at the University of Melbourne, was one of the researchers involved in developing the guidance. “Up until now, the guidance available to GPs has been pretty inconsistent,” she said.
“These guidelines will give doctors better tools and help them explain what breast density means for each individual person, and when to consider further tests or a formal risk assessment.”
She said the guidelines were also designed to avoid unnecessary over-screening or adding to women’s anxiety if they do have dense breasts – “having high breast density is not to say someone will develop breast cancer”, she said.
The goal of the guidance is not to send every woman with dense breasts for more tests, she said, but rather to help identify which of those women might benefit from additional care, especially if they have additional risk factors.
The Royal Australian College of General Practitioners’ breast medicine chair, Dr Katrina Tiller, said BreastScreen has been reporting breast density to women for a number of years, and in some states already advises them to discuss results with their GP.
“This is a nuanced area, and GPs need support to provide their patients with evidence-based advice,” she said.
“The guidance is both needed and welcome. The focus for now is getting this information out to GPs and raising awareness. It will be important to monitor the impact of these changes.”
Sullivan, who consulted on the guidance as a consumer representative for the Breast Cancer Network Australia, said she hopes women like her will now have cancer detected sooner.
“I think it’s really going to empower women to have important conversations with their doctors and get the personalised care that they need,” she said.
