"Choosing to keep her fight private, she had been undergoing medical treatment for some time, supported by her closest family and friends," the statement continued.
"She was a bright, beautiful and loving soul who cared deeply about others and who brought life to everything she touched. Her family asks for your understanding of their need for privacy at this time."
Overnight, Kelly's A-list friends have rushed to social media to remember the beloved actress with John Travolta's Grease co-star and longtime friend Olivia Newton-John leading the tributes.
"@therealkellypreston was a radiant, warm and gentle spirit - a loving, devoted wife, mother and sweet friend. My heart breaks for John, Ella and Ben. No words can express my sorrow for her family. Kelly's light shines on in her beautiful children. Xox," Olivia, who is currently living with stage four cancer, penned alongside a throwback photo of the pair.
Meanwhile, Rita Wilson also took to Instagram to honour Preston.
"@therealkellypreston Such a beautiful soul, sparkling eyes exuding kindness and strength. She found the joy in life. She loved fiercely. Loved her beautiful children Jett, Ella and Ben and loved her husband, @johntravolta She was a blast to work with, made everything more fun. She always supported others. Please keep Kelly, John, Jett, Ella and Ben in your prayers. She will be so missed," Rita shared with an album of photos of herself, Kelly and their husbands Tom Hanks and John Travolta from over the years.
Reese Witherspoon released a statement via Twitter, which read: "Deeply heartbroken for the whole Travolta family over the passing of the wonderful, kind, and extremely talented Kelly Preston. I'm sending love and prayers to her husband, her children and everyone who loved her. May She Rest In Peace."
Preston's Twins co-star Arnold Schwarzenegger tweeted: "Kelly Preston was extraordinary. I was lucky enough to star with her and direct her, and her talent was off the charts. She had such a big heart, she was a wonderful wife and mother, and my thoughts are with John and the whole family."
Russell Crowe remembered Preston as "lovely". "Can't remember where, but, met first in late '92 I think. Such a lovely person. In 1995 we auditioned together for Breaking Up. Salma Hayek got that gig. I haven't seen her much, but when I did, she was always the same sparkly eyed gem. Love to her family. R.I.P," Crowe said via Twitter.
Rove MacManus, who tragically lost his first wife to Belinda Emmett to breast cancer in 2006, said: "Adding myself to the many people sending their condolences to John Travolta and his entire family over the terrible news that his wife Kelly Preston has passed away from breast cancer."
Alec Baldwin explained on his Instagram page: "How tragic and sad about Kelly Preston. I shot CAT IN THE HAT with her some years back. She remains one of the loveliest people I ever worked with. Funny. Kind. My heart goes out to John and their family."
"Sending so much love to you and your family in this heartbreaking moment," singer Mariah Carey commented under John Travolta's statement on Instagram.
While actress Demi Moore uploaded a touching throwback photo of their families and mused: "The world has lost one of the most beautiful, kind, generous, tender-loving souls that has graced this earth. Rest easy @therealkellypreston, we will miss you."
Preston is survived by her husband of almost thirty years John Travolta, 66, and their two children daughter Ella, 20, and Benjamin, nine.
In 2009, Kelly and John's oldest son Jett passed away following a seizure.