The then 44-year-old didn't act on the discovery and thought she would wait and see what would happen. It wasn't until Mrs Marsicano's husband Cristian felt the lump that the mother of two visited her local GP.

"My doctor said she wanted me to have a mammogram and based on my age, she wanted me to have an ultrasound because when women are a certain age things aren't always picked up," Mrs Marsicano said.

"When I had my mammogram, nothing showed up, it just showed I had dense breast and didn't see the lump."

Having high breast density can mask or hide breast cancer, as it also appears white on a mammogram, making early detection more difficult.

Mrs Marsicano was one of almost two-thirds of Australian women who had no idea breast density could obscure a lesion or lump on a mammogram, according to new research from Pink Hope.

"When I had the ultrasound, the lump could be seen and the technician suggested a biopsy to determine what it was."

Mrs Marsicano was diagnosed with breast cancer the following week.

"It was really hard, my husband had thankfully come to the appointment with me," she said. "We sat down, and we looked at each other and we said 'what do we tell the kids?'."

Mrs Marsicano had the lump removed and was put through six rounds of chemotherapy. She was referred to have a genetic test done because of her age.

The results found she carried the BRCA1 breast cancer gene which came as a surprise to the now 47-year-old.

"My mother remarried when I was about six or seven, so we found out the gene was on my natural father's side of the family," she said.

"While I speak to them and know them - I didn't know closely about their family history."

The study also found 84.4 per cent of Australian woman are unaware dense breasts increase the risk of breast cancer and that women with dense breasts are four to five times more likely to develop breast cancer.

"The breast cancer diagnosis was really upsetting, but the thing was - it was me, and me alone and I knew I could actually do something about it," she said.

"When I got the BRCA results I got really upset because I knew it's actually beyond me... it meant there were implications for my family."

Mrs Marsicano underwent a double mastectomy and reconstruction of her breasts. She had her ovaries and fallopian tubes removed as a preventative measure not long after.

"I wanted to do everything that I could to eliminate risk and then, if anything happens further down the track, I know I did my best," she said.

"It wasn't a tough decision for me - I think because I already had my children."

Mrs Marsicano said when she told her daughter Amy, now 13, about the BRCA1 gene she asked if it meant she would get breast cancer.

"I said to her 'no - it doesn't mean you will, it just means we need to be more aware and cautious," she said.

"We are now armed with that knowledge and she will be getting checked and will be monitored."

Mrs Marsicano is urging people, in particular woman to be more body aware.

"I think quite often what will happen is women don't look after themselves as much - they're always looking after the family - there isn't much priority in their own health," she said.

"Think of not just yourself, but all those people around you, your families and things like that - it affects so many people around you, not just yourself."

One in eight women in Australia will develop breast cancer by the age of 85. Almost half of women over the age of 50 have not checked their own breasts via self-exam, according to the study.