Hundreds of patients may have received less than full dose of chemo, Cancer Care Ontario finds

Hundreds of cancer patients in dozens of Ontario hospitals may not have received the full amount of chemotherapy drug prescribed to them in the past year, a review commissioned by Cancer Care Ontario (CCO) has found.

CCO found that more than the expected amounts of the drug remained in the IV tubing, resulting in a variation in intended dose delivery to 1,000 patients.

Dr. Robin McLeod, vice-president of clinical programs and quality initiatives at CCO, said Mississauga Hospital brought the issue to the organization's attention in June.

"They were concerned that there were patients at their hospital that may have been getting variable amounts of cancer drugs when it was given to them intravenously," McLeod told CBC Toronto.

"The tubing which the drug goes through had been changed and so there was longer IV tubing ... They'd also changed their pump and that may have led to it."

McLeod cannot say which company supplied the IV tubes.

She said there had also been a change in how hospitals flushed the drug through the IV tubing and that may have also been an issue.

Additionally, she said, the drugs given to patients — pembrolizumab, nivolumab and panitumumab — were much more concentrated in a smaller amount of liquid.

"It's quite likely that there's always a bit of fluid that's left behind, and with that, some of the drugs," McLeod said.

"Given that the drug was diluted in 50 ccs, if they left a relatively small amount it would translate into more that was left behind."

CCO said that when it became aware of the issue, it sent a safety bulletin to all 74 Ontario hospitals that deliver systemic treatment. The bulletin asked the hospital to review policies and procedures to ensure that the intended dose is reaching the patient.

Thirty-five of the hospitals identified issues dating back to the initial administration of the three drugs.

Of those hospitals, 28 identified approximately 1,000 patient records for review by the medical team. While the other seven hospitals identified issues, no patients were treated with the drugs at those sites.

Less than 10 patients needed retreatment, CCO says

"In total there were 1,000 individuals who were identified that might have received a variable amount of drugs but it was thought by the physicians that less than 10 required retreatment," McLeod said.

"As far as we know, all of the patients have been notified but if there is concern we recommend that the patient should contact their doctor who is looking after them."

A spokesperson at North York General Hospital in Toronto all its affected patients have been notified.

"We have four active patients. They have all been notified and we have since rectified the problem," senior communications specialist Nadia Daniell-Colarossi told CBC Toronto.

"When administering highly concentrated monotherapy drugs, it has been identified that some of the dose may remain in the infusion tubing," she wrote in an email to CBC Toronto on Thursday evening. "Since this was identified, North York General Hospital has changed administration techniques to ensure that all of the intended dose is delivered."

CCO said it reported the issue to other cancer agencies in other provinces as well as the Ontario Hospital Association, Health Canada and ISMP Canada, an independent national non-profit organization that monitors medication safety.

They also plan to do a root-cause analysis with ISMP Canada. That process is likely to take six months, McLeod said.