Singer and actress Olivia Newton-John has opened up about battling cancer for the third time.

The “Grease” star, who will turn 70 on Sept. 26, told Australian show “Sunday Night” about the discovery of her third tumor and the more natural treatment she’s using to fight it during a candid interview about her legacy.

“I’m one of millions in this fight…in this journey,” she said. “I see it as part of my mission maybe.”

Newton-John first announced her diagnosis last year after she was forced to cancel a summer tour in order to undergo treatment. She had been in remission since her second time fighting breast cancer in 2013.

However, Newton-John said she is doing well, refining her diet and using cannabis oil alongside radiation treatment to battle the tumor in her lower back. She has cut sugar entirely out of her diet and uses cannabis plants that her husband grows to help with pain and getting to sleep. “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 said.

The cannabis appears to have been so helpful, in fact, that Newton-John said she hopes the plant will be made legal in Australia so that other cancer patients can benefit from it.

Other topics of the interview included Newton-John’s favorite songs and her role in “Grease” – she initially didn’t want the part of Sandy because she thought was too old. But after a personal visit from John Travolta, she changed her mind.