Entertainment TV Sarah Michelle Gellar Shares Touching Tribute to Shannen Doherty During Cancer Battle: She's 'a True Friend' "I've always said she is one of the most loyal friends I've ever known," Gellar shared of Shannen Doherty By Brittany King Published on August 9, 2016 09:30 AM Share Tweet Pin Email Photo: Source: Sarah Michelle Gellar/Instagram Sarah Michelle Gellar is not letting Shannen Doherty battle cancer alone. On Monday, the former star of Buffy the Vampire Slayer shared a loving tribute to her “muse,” Doherty in an emotional Instagram post. “My #mondaymuse (and really every day #muse) is my brave friend @theshando,” 39-year-old Gellar’s post began. “I’ve always said she is one of the most loyal friends I’ve ever known, and now while she is facing the toughest journey of her life, she is sharing it with friends she has never met in the hopes of helping other people who are going through the same struggle. That’s a true friend #FuckCancer.” Doherty, 45, exclusively revealed to PEOPLE last August that she had been battling breast cancer since March 2015. The actress recently opened up to Entertainment Tonight in an emotional sit-down interview where she revealed that her cancer has spread. “I had breast cancer that spread to the lymph nodes, and from one of my surgeries we discovered that some of the cancer cells might have actually gone out of the lymph nodes,” Doherty said. “So for that reason, we are doing chemo, and then after chemo, I’ll do radiation.” “The unknown is always the scariest part,” she admitted. “Is the chemo going to work? Is the radiation going to work? You know, am I going to have to go through this again, or am I going to get secondary cancer?” She continued, “Everything else is manageable. Pain is manageable, you know living without a breast is manageable, it’s the worry of your future and how your future is going to affect the people that you love.”