By james art Jackie Scully, 42, from Greenwich, south London, will walk across the North African terrain on Saturday in memory of her friend who died of the same disease.
The marketing executive has raised more than £150,000 over the past decade by taking on a series of challenges, including climbing 24 peaks in 48 hours in the Lake District.
Ms Scully also broke a Guinness World Record at the London Marathon in April for the fastest marathon time in a 10-person suit, while in July she and 120 people ran 10km from various locations around the country.
Her five-day trek across the Sahara in Morocco will raise funds for Breast Cancer Now, NHS Charities Together and the Willow Foundation, organizations that supported her during her treatment and recovery.
“The Sahara desert is everything to a friend of mine – we were diagnosed the same week with a very similar diagnosis of breast cancer,” Ms Scully told the PA news agency.
“We were the same age and found each other during treatment and did a lot of fundraising together.
“We were very similar ages with similar stories. She was re-diagnosed with breast cancer. I had to live and she died.
“One of the last things she did before she was re-diagnosed was to trek in the Sahara desert.”
Ms Scully was first diagnosed with breast cancer in 2015, aged 32, which led to her right breast being removed and a tummy tuck procedure.
In 2007, at age 24, she also had a pelvis that had hip dysplasia.
“I’m kind of bionic because I was kind of rebuilt from the left side to the right side,” she said.
“But that’s all that happened to me, all my scars, the fact that I don’t even have a nipple on my right side, none of that matters.
“The important thing is that I got my body back – I can live, and I can live in the most spectacular way, by going to the middle of nowhere, to landscapes that many people will never see and sharing this experience with really great friends.” “
For this upcoming challenge, Ms. Scully will have to compete with different climates, rough terrain and dry conditions.
“It’s going to be a real challenge for my hip as I live in almost constant pain,” she said.
“Because of the way my feet are built, it’s very difficult for me to walk on uneven ground.
“This challenge for me is a brilliant way to end the last decade and show myself that you can go an awful long way with the right people by your side.”
To find out more visit Ms Scully’s fundraising page here: justgiving.com/team/100kourway