TORONTO — Hundreds of patients in Ontario did not receive full doses of Cancer drugs because of issues with how the intravenous medications were administered, the agency overseeing cancer care in the province found in a recent review.

Cancer Care Ontario said an estimated 1,063 people were affected, and fewer than 10 needed additional treatment as a result. The agency said, however, that the matter was taken seriously and prompted the updating of guidelines to hospitals on how such drugs should be administered.

“We don’t take this issue lightly,” said Dr. Robin McLeod, vice president of clinical programs and qualities initiatives at Cancer Care Ontario. “We want to make sure that patients are getting the best treatment.”

The dosing issue first arose in June when the Mississauga Hospital west of Toronto notified Cancer Care Ontario of medication being left behind in intravenous tubes after patients received treatment.

“They were concerned that some patients who were receiving some cancer drugs were not getting all of the drug,” McLeod said.

Cancer Care Ontario immediately asked all 74 Ontario hospitals that deliver cancer drug treatments to review their procedures to ensure medication was being administered properly, McLeod said.

“We sent out a survey to understand if this might have been an issue at these hospitals,” she said. “We did this with some intensity.”

Thirty-five hospitals reported back saying they found issues with how three drugs were being given to cancer patients, McLeod said, and 28 of those facilities found 1,063 records where they believed patients didn’t receive proper doses.

Two of the drugs are for immunotherapy, where they boost a patient’s immune system to fight cancer, said McLeod. The third is for targeted therapy that identifies a gene related to cancer, she said.

The drugs are not as diluted as chemotherapy drugs are when given via an intravenous tube, she said. That means if a bit of medicine is left over within IV tubes, not receiving that amount could impact patients, she said.

All hospitals in Ontario that identified issues with dosing have changed how they administer the drugs in light of the review, McLeod said.

“The hospitals have made changes so that it’s not an issue anymore,” she said, noting that those changes may include adding filters or pumps in the administration of the intravenous drugs to ensure all medication is given to the patient.

Cancer Care Ontario said it also notified cancer care agencies in other provinces of the issue.

Cancer Care Ontario will also be conducting a review of the dosing issue with Institute for Safe Medication Practises in Canada, an independent non-profit organization that works with regulatory agencies and other governing bodies to ensure patient safety with medications.

The joint analysis will involve understanding the process by which cancer drugs are administered to patients and that impacts dosing.

Olivia Bowden , The Canadian Press