Generation Why: 10 Celebrities Who Battled Cancer Before 40

Each year, some 70,000 young adults between the ages of 15 and 39 are diagnosed with cancer. And their stories prompted HuffPost Healthy Living to launch a new series called Generation Why, focusing on the unique set of struggles facing this group of cancer patients and survivors, whether it's grappling with fertility, dating or establishing a career while sometimes battling for their lives.

But for some, those difficulties play out on a more public stage. As part of our spotlight on this community, we rounded up 10 celebrities who have faced cancer before the age of 40. Read on for their inspiring stories.