OTTAWA -- The head of the breast imaging section at the Ottawa Hospital says they're booking appointments on evenings and weekends in a bid to clear a massive backlog of patients waiting for routine screening during the COVID-19 pandemic.

"Unfortunately, we are seeing over 24,000 women who have had a delay in their screening in Ottawa," said Dr. Jean Seely during an interview on Newstalk 580 CFRA.

Seely says the Ottawa Hospital has found patients aren't aware that mammography has resumed at the hospital or that they should be booking a screening.

One year after the COVID-19 pandemic began, Seely says the backlog in routine screening means some cancers aren't being detected.

"This means that we know about 150 fewer cancers were diagnosed last year," said Seely.

"So this means that when they come in this year, their cancers have had time to grow and we're seeing that the delay in their screening has led to the cancers being larger at diagnosis and more likely to have spread to parts of their body."

The Ottawa Hospital stopped breast cancer screening at the start of the pandemic in March 2020 for three months while it assessed the guidelines needed to safely provide screening.

"Because we didn't really know how to take safe guidelines or put them into place to make sure that we didn't infect our patients or our staff," said Seely, noting screening resumed at the Ottawa Hospital in June. 

"So we stopped for three months and that meant that most of all these people who were booked for screening had to be cancelled. Then we've learned so much over the last months on how we can do safe imaging during the pandemic, even during the lockdown. So we resumed screening in June with those safe guidelines in place."

COVID-19 guidelines include mandatory masks for all patients, full personal protective equipment for staff and more time between patients for cleaning.

"We have reduced our ability to see as many patients as we were doing," said Seely about the new protocols. "What we've found is that many people aren't realizing that they should book their screening or that we are open and they should come back in, and that it's quite safe to do so."

The Ottawa Hospital and Ontario's Ministry of Health are sending letters to patients who are overdue for screening.  Women between the ages of 50 and 74 will receive appointment reminders from the Ontario Breast Screening Program.

CFRA host Matt Harris asked Dr. Seely what the delay in screening means for a woman's health.

"The bigger the tumour at diagnosis, it's more likely to have spread and it is more difficult on the health care system because it requires more surgery, more chemotherapy and more impact on the women herself – more time off work. It's ideal if we pick it up earlier," said Seely.

"If the woman has a new lump, that becomes a diagnostic test so we will try and expedite that and book the appointments as soon as we can. There's a real difference: if there's no symptoms, that would be a screening mammogram and we would encourage people book that at their next available appointment. If it's a new problem, then they really should come in sooner and get a special mammogram and ultra sound to diagnose what they have.""

Seely encourages any woman 40 years and older to be screened for breast cancer.

"It is very safe to get the imaging done during the pandemic, and it's very important for everyone's health to be able to continue the screening during the pandemic because cancer doesn't stop during COVID."