'I got to ring the bell': Michael Strahan's daughter Isabella reveals brain tumor battle

Michael Strahan's 19-year-old daughter Isabella is battling a malignant brain tumor known as medulloblastoma, the "Good Morning America" co-anchor and his daughter shared Thursday.

"I literally think that in a lot of ways, I'm the luckiest man in the world because I've got an amazing daughter," Michael Strahan said in an interview with his fellow co-anchor, Robin Roberts. "I know she's going through it, but I know that we're never given more than we can handle and that she is going to crush this."

Isabella Strahan was diagnosed with medulloblastoma in late October, nearly one month after she said she began experiencing headaches while beginning her freshman year at the University of Southern California in Los Angeles.

"I didn't notice anything was off till probably like Oct. 1," she said, speaking with Roberts. "That's when I definitely noticed headaches, nausea, couldn't walk straight."

Initially, Isabella Strahan said she thought she had vertigo but a few weeks after noticing her symptoms, she said she woke up on Oct. 25 and realized her condition had taken a turn for the worse.

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"I woke up, probably at like, 1 p.m. I dreaded waking up. But I was throwing up blood," she recounted. "I was like, 'Hm, this probably isn't good.' So I texted [my sister], who then notified the whole family."

Her symptoms persisted, and Michael Strahan said they encouraged Isabella to seek medical attention.

"That was when we decided, 'You need to really go get a thorough checkup,'" he said. "And thank goodness for the doctor. I feel like this doctor saved her life because she was thorough enough to say, 'Let's do the full checkup.'"

"She did an [electrocardiogram, or EKG], there for my heart and like, other stuff, but she didn't have an MRI machine, so I went to [get an MRI] somewhere else," Isabella Strahan said of the appointment. "And then she calls me and she's like, 'You need to head to Cedars-Sinai [Medical Center] right now. I'm gonna meet you there.'"

It was there she said doctors discovered she had developed a fast-growing 4-centimeter tumor, larger than a golf ball, in the back of her brain.

Michael Strahan said he learned the news before Isabella did and "it didn't feel real."

"I don't really remember much," he said. "I just remember trying to figure out how to get to LA ASAP. And it just doesn't feel real. It just didn't feel real."

Medulloblastoma is a type of malignant tumor that accounts for about 20% of all childhood brain tumors, according to estimates published in the Journal of Clinical Neuroscience. About 500 children are diagnosed with medulloblastoma each year.

"But rarely someone who's 18, 19 years old," Michael Strahan said. "But it's still scary because it's still so much to go through. And the hardest thing to get over is to think that she has to go through this herself."

He continued, "Doctors said, 'You shouldn't risk trying to put her on a plane to get her to the East Coast or to another doctor. We know what it is and we should get it out as soon as possible.'"

On Oct. 27, the day before her 19th birthday, Isabella Strahan underwent emergency surgery at Cedars-Sinai to remove the mass.

She said her recollection of her recovery afterward remains foggy, and she had to learn how to walk again with the help of her twin sister Sophia.

"She was heavily medicated, as you could imagine," Michael Strahan said. "But she would have conversations. She had a lot of her friends and they would come over just to sit with her. And there were times when she was in a lot of pain. She was sleeping a lot."

After surgery, Isabella Strahan also underwent a month of rehabilitation and several rounds of radiation treatment.

"So I just finished radiation therapy, which is proton radiation, and I got to ring the bell yesterday," she said. "It was great. It was very exciting because it's been a long 30 sessions, six weeks."

Although she said her treatment left her feeling fatigue, some nausea and dizziness, among other side effects, she said she is "feeling good" overall these days.

"I'm feeling good. Not too bad. And I'm very excited for this whole process to wrap. But you just have to keep living every day, I think, through the whole thing," she said.

In February, Isabella Strahan will start chemotherapy at Duke Children's Hospital & Health Center in Durham, North Carolina.

"That's my next step. I'm ready for it to start and be one day closer to being over," she said.

Although she has kept this part of her life private online, she said she is now ready to partner with Duke to document her journey in a new YouTube series, which will help Duke Children's.

"It's been like, two months of keeping it quiet, which is definitely difficult," she said. "I don't wanna hide it anymore 'cause it's hard to always keep in. I hope to just kind of be a voice, and be [someone] who people, maybe [those who] are going through chemotherapy or radiation can look at."

Both Michael and Isabella Strahan say this experience has given them a new perspective on the important things in life.

"You learn that you're probably not as strong as you thought you were when you have to really think about the real things, and I realized that I need support from everybody," Michael Strahan said. "You think that I'm the athlete, the tough guy, you know, I can come and handle, I'm the father in the family. It is not about any of that. It doesn't matter. And it's really made me change my perspective on so many things in my life."

"Perspective is a big thing," Isabella Strahan added. "I'm grateful. I am grateful just to walk or see friends or do something, 'cause when you can't do something, it like, really impacts you."

For now, Isabella Strahan said she's focused on the future and eventually returning to college when her treatment wraps up.

"I'm looking forward to getting back to college and moving back to California and just starting my school experience over. Not over, but just restarting, being back into a routine and something that's enjoyable," she said.