Central Maine Healthcare CEO Peter Chalke says she was "a determined fighter who displayed tremendous courage, class and grace during her long battle with cancer."
The Patrick Dempsey Center for Cancer Hope & Healing was founded in 2008 by the "Grey's Anatomy" star and his two sisters in partnership with the Central Maine Medical Center in Lewiston, where their mother received treatment.
Amanda Dempsey for five years led the survivor walk during the Dempsey Challenge, an event that raised $5 million for the center.
Center officials say she died Monday surrounded by family. She'd fought multiple recurrences since being diagnosed with ovarian cancer in 1997.