Study shows Canadian women’s early-stage breast cancer care differs from province to province

Canadian women receive different care for early-stage breast cancer depending on where they live, researchers have found.

In a study, published in the journal Current Oncology on Thursday, researchers from the non-profit ICES (formerly known as the Institute for Clinical Evaluative Sciences) analyzed data on more than 50,000 women diagosed with early-stage breast cancer and who underwent surgery in British Columbia, Manitoba, Ontario and Nova Scotia, from 2007 to 2012.

They found the proportions of patients who received chemotherapy, a mastectomy and radiation therapy varied from province to province, and also within each province, depending on whether patients lived in rural or urban areas. They also identified differences in the proportions of patients who were hospitalized or who visited the emergency department.

Among their findings, Ontario had the largest proportion of patients receiving chemotherapy, at 46 per cent, compared with Nova Scotia, which had the smallest, at 38 per cent. In Nova Scotia, nearly 52 per cent of patients had a mastectomy, compared to the other provinces, in which between 33 to 37 per cent had the surgery.

Ontario had the largest proportion of patients who visited the emergency department while receiving adjuvant chemotherapy (31 per cent), but the smallest proportion of hospitalizations (6 per cent). By contrast, B.C. had the smallest proportion of patients visiting emergency (16 per cent), and the largest who were hospitalized (27 per cent).

“When we start looking at these patterns, we’re able to see some substantial variations, which then allows us to figure out: Well, what are we doing differently in the different jurisdictions? Are there things we could learn from each other?” said lead author Monika Krzyzanowska, senior adjunct scientist at ICES and medical oncologist at Princess Margaret Cancer Centre in Toronto.

Dr. Krzyzanowska said the study did not examine the reasons for these differences, nor did the findings reveal whether patients are receiving better care in certain provinces than in others. For instance, she said, she and her team found women in Nova Scotia were the least likely to receive radiation therapy after surgery, but were also more likely to have a mastectomy.

“Whether or not that’s a bad thing or good thing, we don’t know,” she said, explaining women in rural parts of the province may be choosing to have a mastectomy, rather than travel multiple times over several weeks to receive radiation therapy.

But, she said, by identifying these differences in the patterns of care among the provinces, the study allows researchers to further investigate the reasons for them and whether changes are necessary to improve care.

Steven Narod, Canada Research Chair in breast cancer at Women’s College Hospital in Toronto, who was not involved in the study, said the findings did not show big enough differences to indicate significant gaps in care between the provinces. On the contrary, he said, he was reassured by the data, since they indicate almost all patients under the age of 40 across the country, who should be getting chemotherapy, are getting it.

Caroline Lohrisch, a breast cancer oncologist with BC Cancer, who was also not involved in the study, suggested differences in the rates of emergency department visits may reflect the prevalence or lack of family doctors in certain regions, as well as discrepancies in the information patients receive about when they should be seeking emergency care. They may also be because of differences in the networks of support patients have, such as the availability of nurses or oncologists to address their concerns, she said.

While the study includes data only on four provinces, it highlights the need to track the quality and variations in care across Canada on a continuing basis, said Craig Earle, an oncologist at Sunnybrook Hospital’s Odette Cancer Centre and vice-president of cancer control at the Canadian Partnership Against Cancer, who was not involved in the study.

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