Kaisy Knott and her mom, Melany, wait at Reagan National Airport last week for their plane to Mexico, where Kaisy is undergoing experimental treatments for a lethal form of brain cancer. (Jason Andrew/The Washington Post)

At 39, Melany Knott didn’t have a passport.

She’d never flown on a plane. She was too busy caring for four kids, three cows, hogs, horses and dozens of chickens in rural Taylorsville, Md.

That was in January.

This was August. She was telling me all this at Reagan National Airport, as she and her terminally ill daughter headed to their apartment in Mexico and another round of experimental treatment at a hospital in Monterrey, a city in the foothills of the Sierra Madre Oriental mountains. In Mexico, she would be updating other desperate parents who live in Norway, London, Scotland, Italy.

“Never. I never imagined I’d want to go to Mexico. Or any of this,” Knott said. “But you’ll do anything for your kids.”

Knott and her youngest daughter, Kaisy, fly to Monterrey every three weeks, hoping for a miracle.

Their 4-H life was upended just nine months ago, when the headaches Kaisy was having were diagnosed as diffuse intrinsic pontine gliomas (DIPG), an aggressive, inoperable, incurable, 100 percent lethal brain cancer.

“It felt like I was being stabbed in the head,” Kaisy, now 12, explained to me. Her eye turned inward, the pain increased and, slowly, she couldn’t walk well or use her right arm.

And then, in the airport, she raised that right arm high in the air for me. “I couldn’t do that a while ago, before Mexico. Now look.”

With the travel, drugs, hospital fees and doctor payments, the trips to Mexico cost the family $33,000 every time. Insurance covers zero.

So the Knott family drained all their college funds, their savings, leaned on their credit cards, scratched for every penny they could fundraise to pay for treatments they believe are the miracle cure to keep Kaisy alive.

“Every day. Every second I wonder if I’m doing the right thing,” Melany said. And not just because of her daughter.

Thanks to an online discussion group about DIPG, where Kaisy’s progress is the subject of intense interest, 52 kids from the United States and elsewhere around the world have pulled out of their traditional treatments and are now shuttling to Mexico every three weeks, also hoping to make history, to be that child with DIPG who will be the first to become an adult.

But one of those children, Julianna Sayler, who lived on a small farm in Walla Walla, Wash., just died Friday. She was 8 years old and had been treated in Seattle and London before getting treatment at Hospital Angeles in Monterrey.

Kaisy is so famous there, she and Melany are escorted by medical staffers acting as bodyguards when they move around the hospital. Because desperate families want to see Kaisy, to touch her and talk to her and learn for themselves whether she is the one.

This awful form of cancer first gained recognition among American doctors in 1962, when astronaut Neil Armstrong’s daughter, Muffy, had those same stabbing headaches that Kaisy had. Her eyes, just like Kaisy’s, began to turn inward. She died just months after doctors discovered the tumor at the base of her brain. Since then, between 200 and 400 kids have died of DIPG every year, very few of them living longer than a year after diagnosis.

DIPG is especially brutal because it’s a tumor that forms in the brain stem, in an area called the pons. The pons is really the control center for subconscious life. It’s where the heartbeat, breathing, swallowing, eye movement, eyesight and balance are controlled.

So far it has been impossible to operate on. And because it is behind the blood barrier, a semipermeable membrane inside the brain, effective doses of chemotherapy, radiation or most anything else can’t get to it.

The cancer most commonly hits kids between 8 and 10 years old. The dozens of Facebook pages, GoFundMe campaigns and family home pages are difficult to look at. All of them have side-by-side photos of smiling, happy kids in soccer uniforms, at swimming pools or at school, then the unrecognizable, bloated faces, crossed eyes and withered arms of kids in wheelchairs. Transformations that often happen in a matter of a couple of months.

“Our kids aren’t cute. That’s one problem,” Melany said. “And I just think not enough of them are dying for the doctors to really look for a cure.”

Kaisy Knott, 12, lies beside her 1,500-pound cow Maddy at the Howard County Fair earlier this month. (Family photo)

Ophthalmologists kept trying to fix Kaisy’s lazy eye, which started turning inward last fall. Doctors kept giving her Motrin for her headaches. Finally, after she called her mom screaming because her head hurt so bad, a hospital did an MRI exam on her brain in November. By 10 that night, Kaisy’s parents were told she probably had only six months to live.

“They basically just told us to make memories, there’s nothing they could do,” Melany said.

Kaisy underwent the traditional course of radiation and steroids at Johns Hopkins Medical Center and then moved to Children’s National hospital in Washington. Her face and body ballooned. She lifted her shirt to show me a tween body covered in slashing, red stretch marks. She kept going to her 4-H events, showing her hogs, taking her steer, Smokey, in and out of the barn every day. “He’s 1,405 pounds now,” she said.

“I wasn’t going to stop living,” she said, shrugging, pulling another sip on her Starbucks vanilla creme. “You don’t just stop and die.”

At night, Melany spent hours learning everything she could about the brain, about the pons, where the tumor is located, and the treatments out there.

She runs a small business cleaning offices and homes. But her new side gig is amateur neuroscientist, and she explains the minute detail of neural functions with the same precision that world experts did when I called them.

“You have to learn all of it cold,” she explained. “Or the doctors will eat you alive.”

She followed the Web pages of kids getting revolutionary treatments in London — where they create a port right in the head, with tiny catheters delivering drugs directly into the tumor. She read about kids going through radiation treatments in Australia, looked at all the pictures of their bloated faces, wheelchairs at the beach and amusement parks, making memories.

She began keeping records, checking off the kids who died, highlighting the ones who lived longer than most.

In January, she settled on where to pin her hopes: Mexico. The kids who had the inter-arterial treatments and immunotherapy there lasted the longest. Her charts told her that.

Melany Knott shows a photograph of her daughter Kaisy's brain at Reagan National Airport. (Jason Andrew/The Washington Post)

Kaisy’s tumor was only two months old. The other kids who had gone to Mexico — and didn’t survive — arrived after the tumors were more advanced.

That’s the thing with DIPG. It moves so fast, parents don’t have more than a few months to decide on a course of action. And so many of them hop around — Germany is doing something new, now London — that solid data on what really works is hard to come by.

The cocktail of chemotherapy drugs used in Mexico isn’t too different from what most children were getting in other hospitals, according to families. Because the doctors in Mexico aren’t working with other researchers, it’s not clear whether what they’re doing would pass muster with the FDA.

Still, something in Melany’s gut told her it was the right place to try to save Kaisy.

“I told my husband I’m getting on a plane,” Melany said. “He was so mad at me. He didn’t believe it. He just wanted to make memories. I got a passport in three days and got on a plane by myself. He wasn’t talking to me.”

After meeting the doctors and showing them all Kaisy’s records — she keeps them organized in a flower-covered three-ring binder — the oncology team agreed to treat Kaisy.

In February, they went for the first treatment.

Within two weeks, Kaisy was feeling better. They stopped the steroids, and she began to slim down, leaving behind that road map of stretch marks. She could walk with less pain. And she could move the right arm that had stopped functioning.

Doctors in the United States are working on this confounding cancer.

Javad Nazarian leads a research team specializing in DIPG at Children’s National Health System. He believes that doctors will make huge strides in controlling DIPG soon and that it will be a combination of treatments — chemotherapy, radiation and immunotherapy.

“The tumor is sitting behind the blood-brain barrier,” Nazarian said. “Crossing the blood-brain barrier is not easy. Most drugs do not cross.”

Some treatments involved higher dosages of drugs. But Nazarian said that kids aren’t just little adults — dosages can seriously affect the rest of their bodies, and bigger dosages aren’t always beneficial.

Doctors from across the country are able to share data thanks to donations from families who have lost children to DIPG. Parents and researchers are pushing for more federal funding. Nazarian said he cannot comment on the treatments in Mexico, because doctors there haven’t made all their data public.

Melany Knott has a tattoo of the word “Believe” on her left arm as she fights to keep her daughter alive. (Jason Andrew/The Washington Post)

One of the children whose progress sent other families to Mexico, Parker Monhollon, a 9-year-old from Kansas, died last month.

“Parker. That was a hard one,” Melany said.

But she still believes it’s the right thing for Kaisy.

The hotels in Monterrey are expensive, so Melany found an apartment. And an Uber driver named Cesar, a medical-school student, became their Mexican cousin.

The 10 or so days they spend during every treatment in Mexico are endured, not enjoyed.

“I hate it there,” Kaisy said. For her, Mexico isn’t tortillas or the beach or anything else an American kid might associate with our southern neighbor.

“We’re country people,” Melany said. “Monterrey is a city. We’re not comfortable there.”

But she’s impressed with the way they’ve been treated. “The people. They are so nice to us. The doctors. It’s like the humanitarian part is the most important part of medicine to them,” Melany said. “Once I told them: ‘Why are you being so nice to us? Is it because you think we’re rich Americans? Because we’re not.’ ”

“And they said that, no, the people are important to them,” she said.

Because Cesar knows Kaisy loves animals, he created a fish tank and got baby turtles for her to play with while she’s there for her treatments.

At home, their local Mount Airy 4-H club has held fundraisers for them. There was a steer auction. I met them at a Howard County Fair demolition derby, where three cars were racing on her behalf.

For Melany, Mexico is a Hail Mary.

“Listen. According to the doctors, we should have buried Kaisy by now,” she said. “It’s been nine months, and when she gets back from Mexico this time, she’s going to show her hogs at the Maryland State Fair. That’s something, right?”

Twitter: @petulad

Find Kaisy’s fundraising pages at and her Kick Butt KK page on Facebook.