Unknown, deadly and hard to detect breast cancer factor revealed
One of the biggest risk factors for breast cancer is something most women have never even heard of.
'Breast density' makes the disease up to five times more likely and harder to detect.
Regular mammograms were not enough to save Allie Tesoriero's mum Petrina.
A deadly lump in her breast was detected too late.
"The tumour wasn't picked up in the first mammogram, but by the time she had her second, the tumour had already progressed to an advanced stage," Allie Tesoriero said.
'Breast density' means less fatty tissue and more fibrous, glandular tissue, which Allie's mum had.
It appears white and solid in mammograms and can mask lesions.
"It's not related to size, shape, the appearance or feel of the breast," Professor Mary Rickard from Sydney Breast Clinic said.
"Firstly, you're more at risk of getting the disease and secondly, of it not being able to be detected on the mammogram."
However, it's a major risk factor few are aware of, despite it affecting one in two women under 50 and 40 per cent of women over 50.
Experts encourage women to ask if they have dense breasts when they have a mammogram.
If the answer is yes, discuss with your GP if an MRI, ultrasound or 3D mammogram should be the next step.
"There's a significant improvement in being able to find cancers if you do 3D mammography," Professor Rickard said.
Breast cancer groups want advanced screening technologies offered more widely as part of the free national program.