Ontario will appoint an independent third party to investigate how watered down chemotherapy drugs were given to more than 1,100 patients, some for as long as a year, Premier Kathleen Wynne said Thursday.
"It's unacceptable that this should have happened, that the doses would not have been accurate," said Wynne.
"The minister is pulling together all of the people who are necessary to figure out what happened, to get to the bottom of it, to understand how this happened and whether there's something systematic that needs to be addressed."
Many hospitals mix the medications themselves, but four hospitals in Ontario and one in New Brunswick all used the same supplier based in Hamilton, Marchese Health Care, to prepare the drugs.
There was too much saline added to the bags containing the chemotherapy medications, in effect watering down the prescribed drug concentrations by three per cent to 20 per cent, according to Cancer Care Ontario.
The five hospitals are contacting the affected patients to arrange quick appointments with their oncologists. Family members of Ontario patients who died are also being contacted.
Health Canada, the provincial governments, Cancer Care Ontario and the Ontario College of Pharmacists are investigating the watering down of the cancer medications. The hospitals are also conducting their own probes.
Dr. Carol Sawka, an oncologist and spokeswoman for Cancer Care Ontario, said the agency doesn't know how many hospitals mix the drugs themselves or have it done off-site.
The third-party review will try to determine if the problem is systemic or just an isolated incident, said Health Minister Deb Matthews.
Asked whether the privatization of the preparation of chemo drugs was a factor, Matthews said "that's an important question."
"I don't want to speculate too much, but I know that cost is not likely," she said. "But that is a question."
The supplier, Marchese Hospital Solutions, said concerns over the drug mixtures were the result of "a difference between the manner of administration used in some hospitals that was not aligned with how the standardized preparation has been contractually specified."
The medication wasn't "defective," it said in a statement on its website.
"We are confident that we fully met all of the contract requirements including both volume and concentrations for these solutions," it said.
But questions have been raised about the impact the lower-than-intended doses of the drugs might have had on the patients and whether or not those who have died could have lived longer with proper doses.