Don't Stop Believin' was not the most successful of Olivia Newton-John's many hits. The song spent one week at the top of the Billboard Easy Listening charts in 1976 and has been overshadowed by numbers such as I Honestly Love You, Let Me Be There and Physical.
But for Olivia, the song is currently the soundtrack to her life. In particular, a couple of lines in the chorus provide the motto that is helping her get through each day. The words "Don't stop believin', you'll get by; Bad days, bad days will hurry by," have had special meaning since the cancer she was first diagnosed with in 1992 returned last year.Olivia, who turns 70 on September 26, has a tumour on the base of her spine but says she's optimistic at her chances of beating the cancer.
"I believe I will win over it," she reveals in a TV interview. "That's my goal."
She also admitted that this is actually the third time she's fought the disease. Back in 2013, the Grease actress underwent treatment for a tumour on her shoulder but decided not to tell anyone other than close family and friends.
"I thought, 'This is not something I need to share with people. It's my life and I want to keep it to myself.'"
That cancer was discovered after Olivia was injured in a car accident while on her way to visit her sister Rona Newton-John, who was dying of brain cancer.
"The seatbelt hit me really hard and a lump came up," she tells. "I went to see the doctor and we thought it was something to do with the accident. Time went on and it turned out to be more than that."
Olivia turned to conventional medical treatment and natural therapies, which shrank the shoulder tumour. But now the cancer has spread to her spine and once again she's been undergoing radiation therapy and using natural remedies. She has completely cut sugar out of her diet, which has led to huge weight loss, and is taking cannabis oil for pain.
The Grammy Award-winner counts herself fortunate that husband John Easterling (66) is the founder of the Amazon Herb Company and that they live in California.
"I am very lucky that I am living in a state where it is legal and that I have a husband who is a plant medicine man. He makes tinctures which help me with pain and sleep," explains Olivia, who is mum to daughter Chloe Lattanzi (32).
When Olivia was first diagnosed with breast cancer, she was 44 and had just lost her dad Bryn to cancer in the same week. She underwent a partial mastectomy, chemotherapy and breast reconstruction, and also took herbal formulas, practised meditation and focused on a "vision of complete wellness."
Pronounced cancer-free, she used her experience to help others overcome the disease by opening the Olivia Newton-John Cancer Wellness and Research Centre in her home city of Melbourne.
It's a centre that not only treats patients but carries out research and clinical trials.
"I believe when you go through something difficult, even something as dramatic as cancer, that something positive will come of it," Olivia says.
"That's exactly what the Olivia Newton-John Cancer Wellness and Research Centre is – a positive healing centre to support people on their cancer journey. I have been introducing wellness programmes in a cancer hospital environment to patients who go there to the kind of therapies I was able to have access to but most people can't afford."
Her dream is for cancer to one day become a "thing of the past", but unfortunately for Olivia, who also owns Gaia, an Australian spa and health retreat, it is now very much a part of her present.
When she began suffering back pains last year, she thought she had sciatica. For months, she put up with pain so bad that sometimes she struggled to walk.
"It didn't occur to me that it could be the return of the cancer until a year went by and I was still in excruciating pain. I had an MRI and we found out it was in there," she recalls.
Olivia, who is releasing a memoir called Don't Stop Believin', says she would be lying if she said she never gets scared about her future now the cancer has returned.
"There are moments; I'm human," she confesses.
But she stops herself from doing that by "having a focus on other things and not thinking about myself all the time. There are other people out there doing much worse than me. I am a very privileged person and I am aware of that. I am one of millions on this journey, and I see it as part of my mission. I'm still treating it naturally and doing really well."