Entertainment TV 'American Idol' 's Jax Reveals She's Battling Thyroid Cancer: 'I Don't Think I Have Ever Experienced Anything Scarier' The singer was diagnosed with cancer in April but is planning to run a marathon in November for charity By Melody Chiu Melody Chiu Instagram Twitter Melody Chiu is a Senior Editor for PEOPLE. She has been with the brand since 2009, editing, writing and reporting across all entertainment verticals. She oversees PEOPLE's music and events coverage and has written cover stories on Taylor Swift, Selena Gomez, Melissa McCarthy, Blake Shelton and Sandra Oh. The Los Angeles native graduated from the University of Southern California and has appeared on Extra!, The Talk, Access Hollywood and Good Morning America. People Editorial Guidelines Published on August 8, 2016 07:15 PM Share Tweet Pin Email Photo: Michael Becker/FOX Jax left everything she had on the American Idol stage each week when she competed on the show’s fourteenth season, but for the last few months, the singer has been secretly battling cancer. In a new interview with My Central Jersey, Jax reveals she was shockingly diagnosed with thyroid cancer in April shortly after performing at a show. “It was very unexpected,” she says. “When you’re 20 years old, you have this ‘Superman’ entitlement mentality. Like you’re indestructible. Thank God I have people in my life that were there to help me deal with this when my reality finally clicked for me. I’m a tough guy, but I don’t think I have ever experienced anything scarier.” In the days leading up to her diagnosis, the Idol contestant was “waking up in a very dark place every day,” she says. “Stress has always been a weight in my life, but over the course of a few weeks something felt different. While grocery shopping with my parents, I felt a small lump on my throat.” After visiting the doctor, she was diagnosed with Hashimoto’s Disease and was found to have 18 tumors on her thyroid. Twelve of the tumors tested positive for cancer. The star had her thyroid taken out and has been undergoing radiation treatment in New York. And though she’s spent most of the summer at home, the singer is planning to participate in the 2016 TCS NYC Marathon in November to help raise funds for Tuesday’s Children, an organization that supports youth and families affected by terrorism or traumatic loss. “The work, pressure, & travel in music is not always so forgiving on the mind and heart. It absolutely takes its toll on your body,” Jax captioned an Instagram post on Monday. “Sometimes I think the universe is yelling at me to slow down and I just blatantly ignore it.”