When Caitlin Meaney found out she had cancer, an avalanche of thoughts tumbled through her mind.

"Will I be in bed all the time?"

"Will I ever ride a bike again?"

Last year, the then 14-year-old thought she'd twisted her right arm or slept on her shoulder incorrectly. To make sure it didn't get worse, she took a break from her favorite activities—playing sports, jumping on her best friend's trampoline, and riding her bike with her dad.

"I thought I was just sore and the pain would go away," she says. "But it soon got to the point where I realized this wasn't just an 'I slept on this wrong' problem. Something was up."

In April 2016, a family doctor diagnosed Caitlin with tendonitis and prescribed physical therapy. When the physical therapist concluded that the shoulder and arm weren't healing, an orthopedic specialist was called in.

"An X-ray showed a mass," Caitlin recalls. "He didn't know what it was, though. It could have been a bone infection or a tumor, but he said, 'Don't freak out until we know what it is.'"

To identify the mass, Caitlin was referred to Cedars-Sinai orthopedic oncologist Dr. Daniel Allison in July 2016. After reviewing her medical history, Dr. Allison suspected osteosarcoma, a type of bone cancer that often appears in adolescence.

A battery of tests confirmed his suspicions: The source of Caitlin's pain was a 9-inch cancerous tumor sitting on her shoulder.

"I don't think it hit me right away. It felt like a dream," says Caitlin. "I kept telling myself, 'This isn't happening. This isn't happening.'"

Caitlin's treatment started with 10 weeks of intense chemotherapy, followed by a surgery that removed the tumor and replaced part of the bone in her arm with a titanium rod, then 20 more weeks of chemotherapy, and finally physical therapy.

The day after Caitlin's first chemo treatment, she and her family went to see Guns N' Roses at Dodger Stadium. To celebrate her last chemo treatment, they went to a Green Day concert.

Caitlin comes from a family that loves making and listening to music. Her father and brother play the guitar, and for 5 years, she has played the trumpet.

"I always say music and laughter are a key part of happiness and Caitlin and her family prove it," says Dr. Shivani Upadhyay, one of the pediatric oncologists on Caitlin's care team. "She's amazing, as is her family."

Caitlin is 15 now and back to playing in her high school marching band, this time as part of the percussion ensemble.

She admits it's a challenge, but she's up for it, especially since the instruments she plays—like the snare, keyboard, and cymbals—give her arms a workout, or as Caitlin puts it, "extra physical therapy."

"A year ago, I was worried I wouldn't be able to ride a bike or get on a trampoline. Now I can do anything I want!" she says.