At first glance they could almost be mistaken for mother and daughter. But the bond shared by glamorous Australian singing stars Olivia Newton-John and Delta Goodrem runs even deeper than most family relationships.

Not only have both women enjoyed extraordinary success on the world stage, but both have battled - and beaten - cancer.

And now they've recorded a song to encourage other cancer sufferers to believe they can successfully fight the illness.

The song, Gotta Be Right Here With You, was recorded in Byron Bay early this month and will be released to coincide with their three-week, 228km fundraising walk of the Great Wall of China that starts on April 7.

They'll be joined by Cliff Richard, Jane Seymour, Johanna Griggs, Kieren Perkins and a host of celebrities on the walk, which will raise money for Olivia's Cancer Centre Appeal. It's yet another milestone for both women, whose lives were irrevocably changed when they were confronted with cancer.

And they're delighted to work together to support other victims of the deadly disease.

'Delta's been through a lot for her years. She's like my daughter - very composed, very smart, very talented,' says Olivia, who was diagnosed with breast cancer in 1992.

'I suggested the song to her. It was a big ask, but the answer came back yes and I was absolutely thrilled. I didn't actually expect she would be available to do it, but Delta created the melody and I wrote the lyrics.

'It's a real empathy song, and I hope when people listen to it that it will inspire them, and give them hope that you can go through these things and come out the other end.

'It's about saying: "Don't give up, here I am, I've been through that same journey.'''

For Delta, who was just 18 when she was diagnosed with Hodgkins lymphoma, the collaboration with a woman she's idolised since her youth was a dream come true.

'We had the most beautiful weekend together recording,' says Delta, now 23.

'We talked about everything. We're really spiritually connected in so many ways and on so many levels. We both feel it, and in the song we sing about it. It's a very special bond.'

Delta, who's now engaged to pop star Brian McFadden, says cancer changed her life.

'You become a different person. I lost my innocence to cancer. And I mean that in every sense. The world looks so different - it wasn't as safe a place as what I thought.

'I saw and felt things I'd never seen before - extreme pain, extreme sickness,' she says.

'It's not only your looks that change, like my long hair. It took a year and a half for my skin to return to normal. I was just a baby. It was a big emotional thing to go through.'

She recorded the song with Olivia to share the triumph of her recovery, and to let people struggling to beat the disease know that life can, and does, go on.

'It's exciting that we're doing it for such a wonderful cause. It couldn't be more exciting!

'It worked so well because Olivia's great with lyrics and I came in with the melody. And I hope that when people hear it they listen to the lyrics and understand.

'We want to raise awareness that you need to check yourself. If you catch the disease early, you can do something about it.

'I found this great quote recently - that we were all born with rainbows, but that life takes over and the colours start to fade
a little. We all need to have those moments where we bring them back,' Delta says.

Since being diagnosed 15 years ago, Olivia has been a tireless advocate for breast cancer awareness and research. She promotes the Liv Kit, a breast self-examination product, is co-owner of the restorative Gaia Retreat & Spa in Byron Bay, and her current album Grace and Gratitude reflects her positive, inspirational attitude to life.

But she says everyone is capable of finding an inner strength when they need to.

'Everyone's surprised by how strong they can be, but you have to be,' Olivia says. 'There are people who help you, but you have to do it yourself really, and you find your strength.

'Delta and I do have a real bond. It's a tough battle. But I don't find life scary.'

Olivia, who says she's planning to spend more time in Australia in coming years, has been walking and working out at Curves, a women's only gym that provides intensive 30-minute workouts, in preparation for her massive walk along the Great Wall.

'It's going to be a real challenge. I turn 60 this year - I'm insane,' she laughs.

'But it's exciting. And I feel lucky to be here. When I was diagnosed 15 years ago I didn't expect I'd still be around, but I'm happy, I'm healthy. And I'm still here.'

Support Olivia and your New Idea team members Samantha Riley and Johanna Griggs at www.greatwalktobeijing.com as they walk to raise funds for the Olivia Newton-John Cancer Centre.