Olivia Newton-John opens the door to her "mission" against cancer

Singer and actress Olivia Newton-John spoke of a third cancer diagnosis, saying she thought she was winning the battle.

The 69-year-old Grease star told the Australian TV show Sunday Night that she was now using medicinal marijuana and other natural remedies.

Newton-John survived her initial diagnosis of breast cancer in 1992 but revealed that she had returned in 2013.

A third diagnosis, of a tumor in the lower back, was made last year.

The new diagnosis is stage 4 breast cancer metastasized to the spine.

In the moving interview of Sunday Night, she said, "I am one of the millions in this fight. I should not say fight … in this trip.

"Many people see it as a fight, and wherever you choose to see it, it's your prerogative, I see it as part of my mission."

She said that natural treatments "went very well", even though radiation therapy was also involved.

"I believe I will win and that's my goal."

Newton-John has called on Australia to enact the laws of the US state where she lives, California, and to allow the medical use of marijuana.

"My dream is that soon in Australia, it will be available to all cancer patients and people who are going through cancer that causes pain," she said.

The winner of four Grammy Awards admitted moments of desperation, but stated that she had "an incredible career" and "no complaints".

After surviving his cancer diagnosis in 1992, Newton-John became a prominent activist and established the Olivia Newton-John Cancer and Wellness Research Center in Melbourne.