Olivia Newton-John has been diagnosed with cancer for the third time in three decades.

The Australian singer and actress revealed the news in a profile interview with the country’s Seven Network public affairs program, “Sunday Night.” She said doctors found a tumor in the lower base of her spine in 2017.

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In 1992, Newton-John found a lump in her right breast and was diagnosed with breast cancer. She had nine months of chemotherapy and a double mastectomy, and afterward announced she was cancer-free. She has since become a breast cancer awareness advocate.

When her breast cancer metastasized to a mass in her shoulder 20 years later in 2013, she kept it private. "Sunday Night" reported she treated the disease with conventional medicine and natural methods to help her immune system, and although the tumor got smaller, a third tumor was found in her lower back in 2017.

"I'm one of millions in this fight ... I shouldn't say fight -- in this journey," Newton-John said. "A lot of people see it as a fight, and whatever you choose to see it (as) that's you're prerogative. I see it as part of my -- whatever you want to call it -- I see it as part of my mission, maybe."

Newton-John said she’s doing well on her treatment, which includes a healthier diet, cutting out sugar, radiation and cannabis oil for her pain. Her husband, John Easterling, grows a small amount of the plant for her.

“In California, it’s legal to grow a certain amount of plants for your own medicinal purposes, so he makes me tinctures,” she said. “They help with pain. They help with sleep. “I’m very lucky I live in a state where it's legal and that I have a husband that is a plant medicine man. And my dream is that in Australia, soon it will be available to all the cancer patients and people going through cancer or any kind of disease that causes pain.”

The full "Sunday Night" interview can be watched on YouTube. Newton-John speaks about her recent diagnosis around the 36-minute mark.