ADDISON, Maine — Jason Poole, 15, won his fight against leukemia, but he came out battle scarred.

Poole has a learning disability called post-chemotherapy cognitive impairment, according to his grandfather, Glenn Shands. Glenn and his wife, Laura, are Jason’s guardians.

“We’re hoping it’s not long-lasting, but no one can tell us and no one knows,” Glenn said.

Despite the disability, which affects memory and processing speed, Jason gets As and Bs through Maine Connections Academy, the first virtual charter school approved by the state. He is in 10th grade and was named the February student of the month.

“Jason is finding success academically. He’s a positive person and student who is working hard,” Karl Francis, principal of the South Portland-based online school, said. “What a great kid.”

Cancer struck when Jason was 9 years old. He kept getting fevers. Doctors would treat them with antibiotics, but the fevers always returned.

Jason said he also remembers getting chest pains and being out of breath.

“I couldn’t walk from one room to another without being out of breath,” he said.

In the spring of 2010, after a series of additional tests requested by his grandparents, doctors called and told the family to bring Jason directly to the emergency room.

“On the drive to the emergency room, I was, like, ‘Yeah, no school,’” Jason said. “That excitement didn’t last for real long.”

Test results were grim.

“The test showed that he had a huge tumor in his chest that was pushing on his airway, heart and lungs,” Laura said.

Glenn described the tumor as “bigger than my fist.”

Even more important was the fact that, according to doctors, Jason was about two days away from having a massive heart attack.

Doctors also found cancer in Jason’s hip bones and lymph nodes. He was diagnosed with acute lymphoblastic leukemia and hospitalized for about a month. He did not have surgery to remove the tumor but instead was given large doses of steroids to destroy it. Then, he spent the next 3½ years in and out of the hospital while undergoing chemotherapy and additional steroid treatments, his grandparents said.

“He questioned whether he was going to die and didn’t understand why he was sick,” Laura said. “It was a really hard time for a little boy.”

During his treatment, Jason developed nosebleeds so bad he had to have transfusions to replace the blood he lost, his grandparents said. He still gets severe nosebleeds, though they aren’t quite as bad.

“It doesn’t bother me,” Jason said.

Jason and his grandparents said after his initial hospitalization, a teacher came to the house to help him finish fourth grade. The following year, Jason enrolled in a cyber school in Georgia, where they lived at the time.

Jason was declared cancer free in August 2013. Then, in December 2014, he and his grandparents moved from Georgia to Maine, where his grandmother had been born and grew up.

“I wanted him to see where I came from,” Laura said.

Glenn is happy with the move.

“This is a beautiful state, one of the most beautiful states I’ve ever seen,” he said.

He also said he hopes Jason, who enjoys hunting and fishing, will enjoy life in Maine.

“He missed his childhood. He really didn’t have a childhood,” Glenn said.

Jason enrolled in Maine Connections Academy in September 2014 in anticipation of the move.

He has a particularly hard time with algebra and struggles with history and English, he said. Science is his best subject.

Although he struggles, Jason doesn’t worry about it too much.

“I work with what I’ve got,” he said.

Glenn noted that Jason puts a lot of time into his schoolwork and sets the bar high for himself.

Jason and his grandparents said the flexibility of an online school is really helpful. If Jason doesn’t feel well, he can get to his lessons later. They also don’t have to worry about missing school for trips to see doctors in Scarborough every three months for regular cancer checkups.

Francis, the principal at Maine Connections Academy, said the flexibility is one of the most attractive features of the online school.

“[Students] are not locked into the traditional timeframe,” Francis said. “They have the flexibility to log in at a time that’s convenient for them. The traditional setting doesn’t allow for that kind of flexibility.”

Jason said he is not sure he wants to go to college because he struggles in high school and is afraid he wouldn’t be able to handle the academics at the higher level. Instead, he is investigating possible career paths he could follow without going to college, he said.

Jason’s grandparents said they worry his cancer will return or that he will develop another form of cancer.

But Jason said he is just living his life and not worrying about it.

“I feel bad that they worry,” he said.