The teenagers, who've had a lot of worries in their lives, attended a prom they call "No Worries."
The teens looked like stars in their beautiful gowns as photographers snapped pictures of them arriving at Madame Tussauds museum in Hollywood.
"It means a lot just to be around people who've had the same experiences and who've been through the same stuff, and maybe not even physically, but psychologically," said Eric Seredian.
The special evening was made possible by the nonprofit No Worries Now.
The foundation, started by college student Fred Scarf, was recognized by ABC7's Pay It Forward. The $7,000 gift it received enabled hundreds of kids to attend this year's prom.
Before it received the $7,000, No Worries Now only had enough money to send about 200 kids to the prom. With the money, it was able to send an additional 300 teens.
"Tonight's the night to forget about the doctors, forget about what's coming next in your treatment. Tonight's just to relax," said Rachael Gottes.
After the illnesses they've dealt with, some said going to the prom felt like a dream.
"It means so much to me to be able to be here, because like a week ago, I was in the hospital," said Kevin Cordasco. "So it's just such a change of my life."
It brings joy to the teens' parents as well.
"All the stuff's she's been through - a lot of surgeries and stuff like that - seeing her out there on the dance floor... it makes me feel really good," said parent Katrena Gipson.