On a shaky home video, Marco Pedersen argues heatedly with a social worker who warns that his son could be apprehended if the family fails to consent to chemotherapy for the toddler, just diagnosed with leukemia.

"Chemo is a death sentence," Mr. Pedersen asserts from behind the camera, as he trails the Children's Aid Society employee down a hospital corridor and insists there are alternative treatments.

Oncologists have made huge strides in recent decades treating childhood leukemia, with long-term survival rates reaching close to 90%. But in surprisingly similar disputes now unfolding in Ottawa and Hamilton, parents have opposed the standard courses of chemotherapy for their children, insisting on shots of cannabis oil in one case, and aboriginal remedies in the other.

When the hospitals called in child-welfare authorities to try to ensure chemo was provided, one Children's Aid Society backed up the doctors' request, while the other said it would not seize the child. Both cases are still before the courts, one hospital taking the unprecedented step of suing a child-welfare agency.

The disputes underscore a fundamental question: do otherwise caring parents have an absolute right to decide on treatment for their sick offspring, or should the state step in when health professionals believe a young patient is in danger?

"It should be the parents' final say," insisted Mr. Pedersen.

"They were obviously given this child for a reason, so isn't it they who are supposed to protect that child and ensure that child comes to no harm?," said the 23-year-old cook. "I used to be a proud Canadian. I was proud of my health care ... Now I come to find out that at the end of the day, I don't have a say in anything."

At McMaster Children's Hospital, pushing for the chance to continue chemotherapy on an 11-year-old girl, president Peter Fitzgerald believes medical expertise must sometimes hold sway.

"The reality is a parent or substitute decision-maker cannot make decisions that will cause harm," said Dr. Fitzgerald. "They don't have that right ... We need to focus on the end goal here, which is saving this girl's life."

The girl is an 11-year-old from Six Nations reserve near Brantford, Ont. Mirroring a strikingly similar case earlier this year, the child was 10 days into treatment for acute lymphoblastic leukemia at Dr. Fitzgerald's hospital last month when she and her family chose to halt chemo. They opted instead for native treatments and three weeks at an alternative health clinic in Florida.

"I don't want the medicine they were giving me in the hospital," the girl, whose identity cannot be revealed under a court-ordered ban, said in a statement. "It made me really, really sick. It hurt my belly for lots of days and my hair fell out. I know now that all those things happened to me because poison was being put in my body."

Evidence indicates that more than 80% of children treated conventionally for acute lymphoblastic leukemia survive to at least five years - considered virtually a cure in oncology - up from only one in 10 who survived as recently as the 1960s. The treatment can take a toll, though. Aside from the miserable side effects at the time, adult survivors of childhood cancer are at greater risk of heart disease, stroke, infertility and even some cancers.

When McMaster could not convince the girl's family that she should remain in chemo, it called in the Brant Children's Aid Society. The agency ultimately decided not to apprehend the girl.

Not only does she have loving parents, but the case should have been sent instead to Ontario's Consent and Capacity board, which has the expertise to resolve disputes over health care, said Andy Koster, the society's director.

"We just weren't at a point where we felt we had a child in need of protection," said Mr. Koster. "We have a lot of power, and I think there's a less intrusive method."

The hospital responded by asking a judge to order the agency to help get the patient into treatment, triggering a days-long court hearing that resumes on Wednesday.

'[Parents] were obviously given this child for a reason, so isn't it they who are supposed to protect that child and ensure that child comes to no harm?'

In Ottawa, both Mr. Pedersen and his wife had initially opposed chemotherapy for son Aiden, diagnosed last month with acute lymphoblastic leukemia. The Ottawa Children's Aid Society was summoned and the mother eventually consented to the treatment. Her husband did not, leading to his access being restricted. Mr. Pedersen is back in court Oct. 14 to argue that the order be overturned. Aiden is receiving chemo in the meantime.

Cannabis oil is an effective treatment, and lacks the brutal side effects of chemotherapy, the father argued. Numerous web sites certainly claim the substance has been used to "cure" cancer in children and others. The scientific evidence is less clear.

Some laboratory and animal studies - but not human trials - have suggested cannabis has cancer-fighting potential and deserves more attention, says an extensive review by Cancer Research UK. It is, however, "highly misleading to patients and their families" to suggest cannabis is a proven treatment, concludes the British charity.

Meanwhile, the Children's Hospital of Eastern Ontario (CHEO) said it was obliged to go to the CAS under the province's Child and Family Services Act.

Similar to laws in other provinces, it suggests parents' decisions are not incontrovertible, stating that there is a duty to report those who deny their offspring necessary treatment.

"We understand that no parent takes a decision to withhold medical treatment lightly," said Eva Schacherl, a CHEO spokeswoman. "But when such a decision threatens the life or safety of a child, we look to the courts to make a final decision."

Indeed, Canadian judges have repeatedly ruled that Jehovah's Witnesses do not have a right to refuse potentially life-saving blood transfusions for their children.

National Post

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