Alexa DiVenere was 17 years old when doctors removed her right lung and pericardium, the protective membrane surrounding her heart.

In high school, Alexa played soccer and the flute, and was a drum major in the band. But during her junior year, those activities began leaving her short of breath with pressure in her chest.

A visit to the doctor revealed devastating news. Alexa had stage IV lung cancer.

“It was such...