The singer overcame the disease for a second time, all completely behind closed doors, before tragically discovering she had it for a third time past year - when a tumour was found in her lower spine.
It turned out the lump in her right shoulder was the return of the breast cancer she thought she'd beaten 21 years earlier.
Olivia told Sunday Night she has chose to treat this cancer with "modern" medicines and natural remedies, as well as cutting out sugar completely and taking cannabis oil for the pain.
Speaking on Australian TV's Sunday Night programme, the singer-songwriter said she was using homegrown cannabis as part of her treatment to fight the disease.
The singer is also "treating it naturally and doing really well", she said.
The star has previously spoken about the shock of the diagnosis, which came on the same weekend that her father died from cancer.
"I thought, 'It's my life, ' and I just made a decision to keep it to myself, '" Newton-John told Australia's Channel Seven. "And, um, so I'm very lucky that I live in a state where it's legal and that I have a husband that is a plant-medicine man", she says.
She revealed in May 2017 that she was battling breast cancer that had metastasized to her sacrum.
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She said: 'In California, it's legal to grow a certain amount of plants for your own medicinal purposes ...
Discussing the alternative treatment, Newton-John writes, "This has helped me greatly with pain and sleep".
"I live in a lovely place, have a wonderful husband, all these animals I adore, I have an incredible career - I have nothing really to complain about".
"I'm a very privileged person, and I'm very aware of that", she said on "Sunday Night".
Asked how she's coping, Olivia admitted: "I have my moments, but I'm not going to have my moment here!" "I have a wonderful husband, I have all the animals I adore, I have an incredible career".
The courageous beauty says she doesn't spend any time feeling sorry for herself, and is aware of how lucky she has been in life.
"A lot of cannabis, my husband grows for me", she said. I have nothing, really, to complain about'.