Most women with early-stage breast cancer had unnecessary imaging done after diagnosis, despite guidelines recommending against it, according to a large Ontario study raising questions about why this occurred.

Most provincial, national and international guidelines do not recommend X-rays for those with early stage, operable breast cancer with no symptoms, because the likelihood of a scan picking up evidence of the cancer spreading has been established in medical literature as extremely low.

Peggy Simionati

Peggy Simionati says she was proactive about treatment decisions for her stage 1 breast cancer 16 years ago. She says she's glad doctors aren't strictly following guidelines about ordering imaging. (CBC)

Dr. Mark Clemons, an oncologist and scientist at the Ottawa Hospital, and his team investigated whether doctors and their patients played it safe and did imaging anyway.

For 26,547 women with stage 1 or stage 2 breast cancer diagnosed between 2007 and 2012, the answer was mostly yes: 85.9 per cent had at least one imaging test, such as an X-ray, bone scan, ultrasound, CT scan, PET scan or MRI, Clemons and his colleagues report in Monday's issue of the Canadian Medical Association Journal.

"Apart from wasting resources, is there really any harm in doing any imaging just in case? There is,"  Dr. Matthew Stanbrook, deputy editor for CMAJ, said in a podcast.

"Not only is such imaging costly, it doesn't prolong survival in this context."

Tests 'reflexive' on part of doctors

Dr. Daniel Rayson, a medical oncologist at QE II Health Sciences Centre in Halifax, is one of the authors of a commentary published with the study.

"Mostly it due to a reflexive testing strategy by surgical oncologists and medical oncologists and perhaps not spending the time we need to spend with each individual woman talking about the downsides of all of these tests," Rayson said in an interview, when asked why the guidelines aren't followed.

Dr. Sunil Verma, a medical director at the Louise Temerty Breast Cancer Centre at the Odette Cancer Centre in Sunnybrook Health Sciences in Toronto, said the findings serve as a reminder to follow the guidelines in conversation with patients. He was not involved in the research. 

"The biggest downside is, if somebody goes through these tests, we may find a small little nodules, which is irrelevant, and it requires us to do some more tests and more biopsies, so there are complications that may arise, there are delays that may happen" that jeopardize treatment, Verma said.

In the study, 80 per cent of the patients were at least 50 years old. They most commonly had scans of the skeleton, thorax, abdomen and pelvis.

Imaging was more likely with younger age, other illnesses, axillary node involvement or if surgery was done in a community hospital. For some of these variables, there is no biological rationale for increased imaging, the study's authors said.

MJ DeCoteau, executive director of Rethink Breast Cancer, which focuses on women under age 40, said she wasn't overly surprised by the findings, given how much fear surrounds cancer. Fear can overshadow evidence, she said.

"We hear woman talking about 'scanziety,'" DeCoteau said. "They want to have the scan done. They want to know what is going on. They want the information, but at the same time it terrifies them."

Hate to be the 1%

The researchers acknowledged they couldn't determine the specific indication why doctors ordered imaging, which could have been for reasons besides breast cancer staging.

Peggy Simionati, 68, was diagnosed with stage 1 breast cancer 16 years ago. After microcalcifications showed up on a mammogram, a surgical biopsy was done and a tumour between one and two centimetres was found and treated with radiation and drugs. A chest X-ray, bone scan and liver ultrasound were ordered, and she's glad doctors aren't strictly following guidelines about ordering imaging.

"I would hate to be the one per cent of the population who would've benefited from the test and found out two years later that it was a little bit late to start treatment," the former teacher in Toronto said.

Studies suggest scans show evidence of metastases or spread in 0.2 per cent of women with stage 1 breast cancer and 1.2 per cent of those with stage 2 cancer.

The study's authors couldn't tell whether patients were free of symptoms, although they noted the literature and clinical experience suggests most patients having surgery for newly discovered breast cancer are asymptomatic.

No one knows yet if the findings apply across all provinces and territories, but the researchers estimated that following imaging guidelines for early-stage breast cancer could save at least $3.4 million a year in Ontario's health-care system.

The study was funded by the patient quality and safety committee at the University of Ottawa's medicine department.

With files from CBC's Melanie Glanz