In June of 2014, Lunden was diagnosed with triple negative breast cancer, which required chemotherapy, surgery, and radiation. An eternal optimist, Lunden wanted to turn her diagnosis into an opportunity to help others. She blogged throughout her cancer treatment and wrote a memoir Had I Known, which documents her battle, and reflects on her life and career. Lunden serves as an ambassador for Amgen’s Breakaway from Cancer, advocates for patients on Capitol Hill, and actively communicates with the cancer community through her social media and on her website.