As a minor, he lacks the legal authority to make such decisions. Whether that is fair or not depends on whom you ask.
"Teenagers don't really have the full capacity to understand the broader picture, " said Kara Kelly, a pediatric oncologist at Columbia University.
She worries that teens don't realize the consequences of their decision and if alternative therapy doesn't work, they could be putting their lives at risk.
A number of studies show "adolescents have some difficulty understanding the finality of death," said University of Florida professor of psychology Jay Reeve. This could, in turn, "impact the ability to make well-balanced life or death decisions."
Raymond De Vries, a member of the bioethics program at the University of Michigan, has a different view.
In his opinion, some young people do have the ability to make responsible decisions about their bodies.
What should be done in Abraham's situation, according to De Vries, is instead of only considering the boy's age, authorities should assess how well he understands his decision and whether he understands the consequences.
Cases like this sometimes boil down to power and authority, De Vries said.
It is a "challenge to [the doctor's] authority when you go away from their suggestion. Their immediate response is, 'No,'" De Vries said.
"Some doctors alienate patients in their beliefs, say there is no data, no science and dismiss it [alternative medicine.]"
It is very important for doctors to acknowledge a patient's belief system, and she says, "see if some kind of compromise could be worked out so alternative beliefs can be supported."
In the end, many experts say, it isn't age or authority that matters, but the ability of doctors and patients to come together and battle cancer as a team.
According to Kelly, "there is nothing that has been proven more successful than chemotherapy," but alternative medicine can be used to support a patient.
She says, "If people believe it helps them, maybe it will help conventional therapies to work better."
Best is now 28 and cancer free. His family was lucky. The case against the Bests was dropped and Billy was allowed to follow his chosen alternative therapy. He has not experienced any return of cancer.
"What helped me was learning there are other therapies out there. I never knew there were other options, he said."
He also says the positive change in his mood helped him get better.
"I felt good about what I was doing, I was taking part in my own treatment."