When Tracy Tarnowski was diagnosed with breast cancer, she opted to have a double-mastectomy, even though her malignancy was confined to only one breast. But the tumour was widespread and aggressive – and she wasn’t about to take any chances.

“I did it because I was only 40,” said Tarnowski, referring to her 2007 surgery. “The decision I made was so I couldn’t have any what-ifs or look back and have any regrets. I did everything I could possibly do to make sure it was gone and wouldn’t come back.

“I had a lot of living to do as far as I was concerned,” the mother of two said from her home in Embrun, Ont., outside Ottawa. “I might have made a different decision had I been 75.”

Age of diagnosis appears to be one factor behind the decision to undergo a mastectomy instead of a less invasive lumpectomy, says a report on rates of breast cancer surgeries across Canada released Thursday.

The joint report by the Canadian Institute for Health Information (CIHI) and the Canadian Partnership Against Cancer show the annual rates for the two treatments vary widely from one province to another.

The rates for women having a cancerous breast removed instead of a lumpectomy, known as breast conserving surgery, was lowest in Quebec, at 26 per cent, and highest in Newfoundland and Labrador, at 69 per cent.

Because figures are in an inverse ratio, the rate for lumpectomies in Quebec was 74 per cent and 31 per cent in Newfoundland and Labrador.

In Saskatchewan, the mastectomy-lumpectomy split was 65 per cent versus 35 per cent, while in Ontario the ratio was 37 per cent for mastectomies and 63 per cent for lumpectomies.

Several factors could explain variations in treatment rates from one jurisdiction to another, including physician practice patterns and patient preferences, said Anne McFarlane, CIHI vice-president for Western Canada.

“It’s important to note that there are two surgeries for people with breast cancer – mastectomy and lumpectomy,” McFarlane said in a telephone interview from Victoria. “Lumpectomy followed by radiation has been shown since the mid-1980s to have equivalent outcomes as mastectomy.”

But, of course, mastectomy is a much more invasive procedure, she said.

“You lose your breast. So from a cosmetic and from a recovery point of view, it would be a more difficult procedure to come away from feeling like you were the same person after the mastectomy as you were before.”

This year, about 22,000 women will have a mastectomy or a lumpectomy followed by radiation.

The report found that a woman’s age seems to play into the choice to go with mastectomy over a lumpectomy.

Rates were relatively high – 44 per cent – for women age 18 to 49. Rates dropped to 35 per cent for those age 50 to 69, then rose again to 45 per cent for women age 70 and older.

“And we think for younger women, that’s because in that age group they’re outside the formal screening (mammogram) programs, so women tend to be diagnosed with more advanced disease and younger women tend to have more aggressive disease,” said McFarlane.

For older women, opting for mastectomy over a lumpectomy could relate to difficulties getting to centres offering followup radiation, as well as less concern about body image.

“We really don’t know the answers for that, but it’s an interesting phenomenon,” she said.

The distance one needs to travel to and from a radiation centre does appear to be a factor.

The 2007-2010 report shows increased numbers of mastectomies corresponding to travel time, with rates exceeding 50 per cent for women who had to drive three hours or more for treatment.

“Radiation following lumpectomy is typically five days a week for between three and six weeks,” said McFarlane. “So although each session of radiation isn’t very long, you have to go to the radiation centre four or five days a week for three to six weeks.

“And if you have a job, if you have little kids, if you have a spouse who’s not well that you have to be there to provide care for – all of those could be barriers to spending that kind of time away from home.”

Dr. Heather Bryant, vice-president of cancer programs at the Canadian Partnership Against Cancer, said the report should help doctors and health-system planners in various jurisdictions “optimize breast cancer care and the experience of women who receive surgery as part of their treatment.”

McFarlane said the report allows physicians to see the bigger picture and how rates differ from province to province.

“It’s only when you can see these analyses done at the national level, where you can see the variations by jurisdiction, that it comes out in such stark relief,” she said.

“I think surgeons and women in Newfoundland, for example, have the expectation that there’s a high mastectomy rate. It’s only when they see that mastectomy rate in comparison with, say, Quebec that they can ask the question: ‘Is this the way that we want it to be? Are we doing the best that we can here?’ “And similarly in Quebec they can also ask that question.”

SHERYL UBELACKER – The Canadian Press