Cassandra Thorburn didn’t want to be a public figure - but if she’s going to be one, this is what she wants Australians to know

Many breast cancer journeys begin with a lump. Cassandra Thorburn’s started with a letter in the mail.

It was a reminder from BreastScreen NSW that she was due for a routine mammogram, without which she may not have been diagnosed until it was too late.

“I literally got kissed on the arse by an angel who sent me my reminder,” Thorburn, 55, told nine.com.au.

Australian women, trans and gender diverse people should undergo free breast screening every two years from the age of 50 to 74, and can request free screening after 75 or from as young as 40.

There were no red flags at Thorburn’s screening, so she thought she was in the clear.

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“The mammogram didn’t show anything in my breast because there was nothing to see in my breast. I didn’t have a lump,” she said.

“What it did show was a grey area on the side of the mammogram towards my underarm.”

An ultrasound, a biopsy, and one week later, Thorburn was told she had breast cancer.

“That doesn’t make any sense. How can you be told you’ve got breast cancer without a lump?” she recalls thinking.

“They couldn’t explain it ... there was no lump I could have found on my own.”

Thorburn had stage three occult breast cancer, a rare form that accounts for less than two per cent of diagnoses in Australia. It occurs when the cancer spreads to other parts of the body (usually the lymph nodes in the armpits) without a visible primary cancer in the breast.

Because there is no lump that can be felt by hand or seen on a scan, occult breast cancer often goes undiagnosed until the later stages, when survival rates drop.

In hindsight, Thorburn believes signs of the cancer may have been there before her life-changing mammogram.

“I was doing Muay Thai at the time, I was quite fit, and sometimes I thought ‘do I have a sore underarm?’” she said.

But Thorburn never suspected it was anything serious, let alone cancer.

Telling her children Jackson, 27, Ava (who goes by Willow), 21, and River, 19, whom she shares with ex-husband Karl Stefanovic, was tough, but at least they were old enough to understand.

“My chemo buddy, who I’ve gone through chemotherapy and surgeries with, she has a one-year-old and a four-year-old,” Thorburn said.

“How do you have that conversation with a one- and four-year-old? I was very fortunate, I’m having a conversation with adults.”

Jackson, Willow and River had never heard of occult breast cancer, nor had anyone in Thorburn’s life, so she started sharing her journey on social media.

The goal was to spread awareness.

Instead, Thorburn’s posts sparked headlines, many of which referred to her as ‘Karl Stefanovic’s ex’ even though the pair split a decade ago.

“I never really had a public profile. Yes, I did Dancing With The Stars and I worked in the media for a long time, but I was not a public person,” she said.

“That was thrown on me because of a traumatic situation I went through in my life, and that was the media’s decision to do that to me.

“The media decided that because I was being divorced from someone, that they would make me a [public figure], but that’s not who I was, nor did it have anything to do with my actual life.”

If she must endure the spotlight, she intends to use it for something good.

Thorburn kept posting about breast cancer as she underwent months of chemotherapy, surgeries, and started radiation, all while still working.

She educated her 14,000 Instagram followers on breast density, which refers to how breasts look on a mammogram and can make cancer harder to see in some cases, and how to access free screening before turning 50.

She even documented losing her hair.

“It’s obviously pretty confronting, because the reason it’s falling out is ... you have cancer and you’re being poisoned through chemotherapy to get rid of it,” Thorburn said.

“So it’s not really about losing your hair. It’s about walking around with cancer, it’s the fear, and that’s always on your mind.”

Thorburn is now cancer-free and undergoing mop-up radiation, but she’s not done sharing her story or educating other women and men about breast cancer.

That’s why she wants other Aussies to shave, cut, or colour their hair to raise vital funds for pioneering cancer research for the Australian Cancer Research Foundation’s (ACRF) Brave Shave 2026.

As an ambassador for the campaign, which kicks off on September 1, Thorburn hopes to raise awareness for rare cancers like hers and remind women to keep up with routine screening, even if they never feel a lump in their breasts.

“It’s about getting things early. Because we all know the earlier you catch a cancer, the less aggressive the treatment and the higher the chance of survival,” she said.

Funds raised through the campaign will go towards life-saving work like the Centre for High-Risk Breast Cancer in Brisbane, which is set to launch in 2026.

It will house a groundbreaking magnetic resonance spectroscopy (MRS) scanner that can spot tiny chemical warning signs in breast tissue years before cancer forms.

Backed by a $2.5 million grant from the ACRF, it has the potential to save lives and spare many Aussies from preventative mastectomies or lifelong medication.

And for Thorburn, that’s worth stepping into the spotlight.

Registrations are now open for the ACRF Brave Shave 2026. Learn more here.