The 59-year-old, who tragically lost her sister Lesley to the disease in January last year, is now calling on women across the country to take part in the annual Cancer Research UK fundraiser, Race for Life.
Marilyn was first diagnosed with cancer in 2004 after finding a lump in her left breast.
Then 45, she insisted her doctor refer her to the local breast clinic where a biopsy confirmed she had Stage 2 breast cancer.
As a result, Marilyn had a mastectomy and 13 lymph nodes removed and has since been treated with Tamoxifen.
In 2011, after losing a lot of blood, a gynaecologist told her she would also need a hysterectomy after a scan of her womb revealed a precancerous tumour Marilyn, from Southampton, was later diagnosed with melanoma in 2012 after a friend noticed a mole on her back appeared to have grown.
Days after having it removed, the mother-of-one learned it was early stage melanoma.
She has since had nine other moles removed.
Then, just a few months later in August 2012, what Marilyn thought was food poisoning turned out to be colon cancer.
After undergoing radiotherapy, she had part of her colon and bowel removed, which revealed two tumours and the spread of the disease to her lymph nodes.
Marilyn had six months of chemotherapy while planning her wedding to husband John, which helped her get through it.
The couple tied the knot in September 2013, weeks after her final chemotherapy session.
Marilyn said: “Until you actually have cancer, you cannot appreciate what it is like to be given that news.
“Many of my friends say they have never met anyone with such a positive mental attitude but without a doubt, it has helped me get through the last few years.
“Every day we hear about the advances being made to tackle cancer and that is why funding research is so important.
“I want there to be a day when people don’t get that cancer diagnosis – or if they do, they know they will survive.”
Last year Marilyn and her sister Paula took part in the Race for Life in memory of their sister Lesley.
Now she’s urging others to sign up.
She said: “I’ve never let the words ‘You have cancer’ beat me.
It has made me want to tell people that cancer doesn’t mean it is the end.”
Jenny Makin, Cancer Research UK’s spokeswoman for Hampshire, said: “We’d like to thank every woman who laces up her trainers and takes her place at the start line at Race for Life.
“One in two people in the UK will be diagnosed with cancer at some point in their lives and we couldn’t continue our life-saving work without public support.
“Every person who crosses the finish line can make a real difference.”
To find your nearest Race for Life event, visit raceforlife.org or call 0300 123 0770.