Celebrity Jackie Collins Kept Breast Cancer Secret from Sister Joan Because She 'Didn't Want to Be a Burden' Jackie Collins, in her final interview with PEOPLE, said "I just felt [Joan] didn't need it in her life" By Alexandra Hurtado Published on September 24, 2015 08:30 AM Share Tweet Pin Email Photo: Kevin Mazur/VF15/WireImage Five days before a six-and-a-half year battle with breast cancer ended Jackie Collins’ life, the bestselling author sat down with PEOPLE at her Beverly Hills home and opened up about her diagnosis, her hopes for the future and her insistence on living every day to the fullest. Subscribe now for instant access to the entire PEOPLE exclusive. For years, Jackie Collins kept a major secret about her health from her famous sister, actress Joan Collins. Jackie didn’t tell Joan that she had been receiving treatment for stage 4 breast cancer since being diagnosed in 2009 until just before she sat down with PEOPLE to give her final interview. The best-selling author died on Sept. 19 from the disease at age 77. Collins only told her three grown daughters, she told PEOPLE, “Because I didn’t want to be on the front of the Enquirer with ‘two weeks to live.’ And I didn’t want people’s sympathy. I think sympathy can weaken you. I don’t live my life that way.” As for her sister, Jackie protected Joan from the news “because it would have really affected her,” she said. “I just felt like she didn’t need it in her life. She’s very positive and very social, but I’m not sure how strong she is, so I didn’t want to burden her with it.” On a recent trip to London, Collins broke the news. “[Joan] was very shocked. She had no idea,” she said. “But she was great. We were emotional. My brother Bill was there too, and he’s fantastic. It was a really good trip.” Collins said she was “not sorry” for keeping the secret about having breast cancer. “I did it my way,” she said, “as Frank Sinatra would say.” “She was my best friend,” Joan, 82, said in an exclusive statement to PEOPLE after her sister’s death. “I admire how she handled this. She was a wonderful, brave and a beautiful person and I love her.” For more on Jackie Collins, pick up the latest issue of PEOPLE, on newsstands Friday. Reporting by ELIZABETH LEONARD