On the back of Alicia Bennett’s favorite T-shirt is her design of a tree with the words, “Go out on a limb.”

The shirt honors the 17-hour cancer operation that removed the 23-year-old college student’s watermelon-sized tumor, along with her right arm and breast, chest wall, sternum and six ribs.

“I use lots of humor to cope,” says Alicia, who has been coping with a desmoid tumor – a type of soft tissue sarcoma – since she...