Jackie Collins has died at age 77.

The acclaimed novelist, who sold over 500 million copies of her books worldwide, passed away after a battle with breast cancer Saturday (September 19). According to Entertainment Weekly, Collins was originally diagnosed with Stage 4 breast cancer over six years ago, "but kept the diagnosis private."

"It is with tremendous sadness that we announce the death of our beautiful, dynamic and one of a kind mother, Jackie Collins, who died of breast cancer today. She lived a wonderfully full life and was adored by her family, friends and the millions of readers who she has been entertaining for over four decades. She was a true inspiration, a trailblazer for women in fiction and a creative force. She will live on through her characters, but we already miss her beyond words," the family said in a statement on her official website.

"She was my best friend. I admire how she handled this. She was a wonderful, brave and a beautiful person and I love her," her sister, actress Joan Collins, said of the news in an interview with People Magazine.

The prolific writer released dozens of novels in her career including The Stud, The World is Full of Divorced Women and The Bitch, and was known for her risque brand of storytelling, exploring the secret, salacious scandals of Hollywood.