LOS ANGELES (AP/CBS SF) — Olivia Newton-John says she has been diagnosed with cancer for the third time in three decades.

Olivia Newton-John attends the Academy Presents “Grease” (1978) 40th Anniversary at the Samuel Goldwyn Theater on August 15, 2018 in Beverly Hills, California. (Photo by Alberto E. Rodriguez/Getty Images)

The four-time Grammy winner, who will turn 70 on Sept. 26, told Australian news program “Sunday Night” doctors found a tumor in her lower back in 2017.

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Newton-John says she’s “treating it naturally and doing really well.” The “Grease” star says for pain, she is taking cannabis oil, made from marijuana her husband John Easterling grows on their ranch in Santa Barbara.

She has undergone radiation treatments and has cut sugar out of her diet.

She said, “I believe I will win over it.”

She said she hopes her native Australia will legalize medical marijuana. In California, cannabis and cannabis oils are legal.

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“It’s helped me a lot and should be available for patients, particularly those going into palliative care,” she Newton-John.

In an interview, she told the Australian Woman’s Weekly, “I have an amazing husband who is incredibly knowledgeable about health and plant medicine so I’m very lucky.”

Newton-John was first diagnosed with breast cancer in 1992, undergoing a partial mastectomy and reconstruction.

She was diagnosed with breast cancer again in 2013.

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