Taylor Swift has revealed that her mother, Andrea, is battling cancer.

The country-turned-pop superstar revealed the news via Tumblr, saying, "I’m writing to you with an update I wish I wasn’t giving you, but it’s important and I’m used to sharing important events in my life with you."

Swift says she asked her mom to visit a doctor for a full health screening this past Christmas, "just to ease some worries of mine." The seemingly routine screening ended with a cancer diagnosis.

She adds that the family have decided to keep the details of her mother's condition and treatment plans private, but says Andrea wanted the fans to know of her diagnosis.

Swift's mom has been instrumental in supporting her daughter every step of the way during her rise to worldwide superstardom, and remains involved in virtually every aspect of her career. She appeared in the videos for two of Taylor's songs.

"She wanted you to know because your parents may be too busy juggling everything they’ve got going on to go to the doctor, and maybe you reminding them to go get checked for cancer could possibly lead to an early diagnosis and an easier battle… Or peace of mind in knowing that they’re healthy and there’s nothing to worry about," Swift says. "She wanted you to know why she may not be at as many shows this tour. She’s got an important battle to fight."

Adds the star, "I hope and pray that you never get news like this."

Swift is currently preparing for her 2015 tour in support of her first official pop album, 1989. The first show is set for Tokyo on May 5.

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