Woman whose cancer was almost missed wants breast density reporting in screening

A woman whose breast cancer was not detected after a mammogram, is calling for more information around dense breast tissue.

Dionne Scott, from Whanganui, was diagnosed in 2024 at the age of 50.

She had found a lump in her breast that was not detected during a routine mammogram nine months earlier.

Six months later, with the lump still there, she returned to her GP and was referred for another mammogram and an ultrasound.

Neither identified the cancer, but because the lump could still be felt, Scott insisted on having a biopsy.

The biopsy revealed breast cancer, and Scott underwent a lumpectomy, followed by radiation and hormone treatment.

"If I hadn't pushed and said, yeah, I want the biopsy, if I just said, okay, I'll wait another year, I'm sure it would have been way more than grade two," she said.

It is estimated that one in 10 women have extremely dense breasts, like Scott.

For these women, standard mammograms may detect only around half of cancers.

The Breast Cancer Foundation said the current one-size-fits-all approach had failed them.

Chief executive Vanessa Sorenson said that while mammograms were the best screening tool for most women, they were not effective for everyone, and there was no publicly funded additional screening for women with dense breasts based on their risk.

"Breast density puts women at higher risk of developing breast cancer, while also making cancer harder to see on a mammogram," she said.

"Yet women are not routinely told about their density through the public screening programme."

Scott said if she had known that having dense breasts both increased her risk of breast cancer and made cancers harder to see on a mammogram, she would have paid for additional testing privately.

Sorenson said she was not alone.

"We're increasingly hearing from women whose cancers were not detected on mammograms and who only learnt after diagnosis that they have dense breasts.

"Women have a right to know about their breast density, but information must be matched with access to screening that is appropriate for their risk."

As part of the Breast Cancer Foundation's 2026 Election Manifesto, it is calling on the next government to:

• require BreastScreen Aotearoa to include breast density in every screening result;
• fund additional screening for women identified as having a higher risk of breast cancer; and
• begin a phased rollout of contrast-enhanced mammography, where clinically appropriate.

Sorenson said contrast-enhanced mammography, or CEM, used a contrast dye to help make cancers more visible.

Research showed it could detect cancers in dense breast tissue that may be difficult to see on a standard mammogram.

"We've all got very different breasts. And for women that have very, very high density, when you have a mammogram, which is still incredibly important, your tumours with dense breast tissue show up white. So they can't be seen," she said.

"We're really also looking to pull forward contrast-enhanced mammography, or CEM. It's a type of mammogram that uses injected contrast dye. And that way, it actually makes areas of unusual blood flow more visible, helping radiologists identify possible cancers."

Sorenson said women needed political parties to move beyond recognising the problem and commit to addressing it:

"Telling women their density is only the first step. Reporting should begin as soon as possible, alongside work to determine what screening women at higher risk should receive.

"Without a funded pathway, women who can afford to pay privately may be able to access additional screening, while others can't. A woman's ability to get the screening she needs should be based on her clinical risk, not her bank balance."

Breast density reporting is increasingly becoming standard practice internationally.

It is mandatory at the federal level in the United States and largely standardised or required across most provinces and territories in Canada, Sorenson said.

Australia has been introducing reporting progressively across states, with women identified as having high breast density advised to discuss their overall risk and possible screening options with their GP, she added.

In 2023, the Royal Australian and New Zealand College of Radiologists, the professional body representing radiologists in both countries, recommended mandatory reporting of breast density.