Lauren Tom is asking fans to keep her family in their thoughts after revealing that her 25-year-old daughter, Ellie, has been diagnosed with osteosarcoma, a rare form of bone cancer. “I wanted to share some tough news today,” Tom wrote. “This is my beautiful daughter, Ellie. “We have a long journey ahead of us,” Tom wrote. Osteosarcoma is a rare type of bone cancer that most often develops in the arms or legs.