(NEW YORK) -- When 7-year-old Mykayla Comstock was diagnosed with leukemia in July, it was less than three days before her mother filed Oregon medical marijuana paperwork so the child could take lime-flavored capsules filled with cannabis oil.
The decision to give Mykayla the capsules came naturally to Erin Purchase, Mykayla's mother, who believes marijuana has healing power. But doctors aren't so sure it's a good idea.
"The first doctor was not for it at all," Purchase told ABC News. "Basically she blew up at us and told us to transfer to another facility."
Their new doctor knows that Mykayla takes about a gram of cannabis oil a day -- half in the morning and half at night -- but doesn't discuss it with them.
"This is our daughter," Purchase, 25, said. "If they don't agree with our personal choices, we'd rather they not say anything at all."
It's legal for a minor to enroll in the Oregon medical marijuana program as long as the child's parent or legal guardian consents and takes responsibility as a caregiver.
And Mykayla is not alone.
There are currently four other patients enrolled in the Oregon medical marijuana program between the ages of 4 and 9, six between the ages of 10 and 14, and 41 between the ages of 15 and 17, according to the Oregon Public Health Division. Severe pain, nausea, muscle spasms and seizures are among the top conditions cited for medical marijuana use.
Mykayla first started to feel sick in May, when she developed a rash, cough and night sweats. By mid-July, doctors found a mass in her chest and diagnosed her with T-cell acute lymphoblastic leukemia a few days later. The family relocated from Pendleton, Ore. to Portland to be near Randall Children's Hospital for treatment, which included chemotherapy.
At first, Mykayla wasn't responding well to her treatment, and doctors said she might need a bone marrow transplant. Then she started taking the cannabis oil pills. By early August, Mykayla was in remission and the transplant was no longer necessary.
"I don't think it's just a coincidence," Purchase said. "I credit it with helping -- at least helping -- her ridding the cancer from her body."
Purchase said she, too, uses medical marijuana. She said it has helped with her kidney and liver disease since 2010, adding, "I feel that it saved my life."
However, Dr. Donna Seger, the executive director of the Tennessee Poison Center and a professor at Vanderbilt University, said cannabis has no effect on liver or kidney function, and is not a medicine for cancer.
"If it does anything, it decreases immunity," she said. "It doesn't fight cancer."
Seger said she has several concerns about a 7-year-old taking pills filled with cannabis oil because there is little research on its long-term effects on children. Cannabis could have potentially negative effects on cognitive development in children, and little is known about regimens lasting months or years.
Purchase said she wasn’t nervous at all about prescribing pot to her daughter, but was unsure what dosage to administer. She started Mykayla with .07-grams at a time.
"It took a while to get her adjusted to it," Purchase said. "She acted more funny when she first started taking it and after a while gained tolerance. Now, when she takes it, you can't even tell. She's very normal."
But Dr. Michel Dubois, who works in NYU Langone's Pain Management Center, is concerned about the addictive qualities of pot, as well as the 50 to 60 different chemicals contained in cannabis oil pills. He said the capsules shouldn’t be administered for more than a month or two.
Although Mykayla's doctors told Purchase she was in remission on Aug. 6 when her blood cell counts returned to normal, Mykayla will undergo two and a half or three more years of chemotherapy so that she can one day be officially cured, Purchase said. That could mean years of more medical marijuana.
Copyright 2012 ABC News Radio