Knowing that mastectomy rates vary across Canada is an important first step in understanding how care can be improved. (Eric Gaillard/Reuters)

Mastectomy rates vary greatly across Canada, and may be tied to the distance a patient lives from a radiation treatment facility, researchers say.

Researchers looked at rates of breast cancer surgery, such as mastectomy and lumpectomy, based on data from nearly 58,000 women in every province and territory who had breast cancer surgery between 2007-08 and 2009-10.

A mastectomy removes the entire breast. It's an invasive procedure with significant recovery time and a risk of complications. The other approach, a breast-conserving lumpectomy, removes only the tumour tissue. Patients have a shorter recovery and generally get a good cosmetic result.

Mastectomy rates for a first surgery for invasive breast cancer ranged from 69 per cent in Newfoundland and Labrador to 26 per cent in Quebec and 39 per cent nationally.

"There is significant interprovincial variation in Canada for several aspects of surgical breast cancer care," Dr. Geoff Porter, a professor of surgery at Dalhousie University in Halifax, and his co-authors concluded in Tuesday’s issue of the CMAJ Open.

Porter called the findings an important first step in understanding how care can be improved.

'You're always wondering did one cell escape.' - Sondria Brown, cancer survivor

Women with longer travel times to a radiation facility, which are usually in major cities, were more likely to have a mastectomy. Long courses of radiation are generally recommended after lumpectomies and travel time appeared to significantly reduce use of less-invasive surgery.

Sondria Brown belongs to a breast cancer support group in St. John's. She opted for a mastectomy.

"You're always wondering did one cell escape, or will it come back in the other breast? I think that's always on women's mind," she said of her decision.

For women in rural Newfoundland, travelling back and forth for treatments can cause such an upheaval in their lives that some can't do it, Brown said.

Newfoundland's Eastern Health said it is aware of the province's high mastectomy rate but wouldn't do an interview.

Porter said the issues are complex. Women may have personal reasons for choosing mastectomies over lumpectomies. In some cases, more aggressive surgery is needed.

The most affluent women were less likely (39 per cent) to have a mastectomy compared with the least affluent (49 per cent.) The reason is unclear.

The study also looked at day surgery and reconstructive breast surgery rates, which were in line with the findings from studies in the United States and the United Kingdom, the researchers said.

The study was conducted by the Canadian Institute for Health Information and the Canadian Partnership Against Cancer.

With files from CBC's Pauline Dakin