breast cancer in canada

Breast cancer is the most common cancer among Canadian women (excluding non-melanoma skin cancer).

    In 2010:
  • An estimated 23,200 women will be diagnosed with breast cancer and 5,300 will die of it.
  • An estimated 180 men will be diagnosed with breast cancer and 50 will die of it.
  • On average, 445 Canadian women will be diagnosed with breast cancer every week.
  • On average, 100 Canadian women will die of breast cancer every week.




High Risk Factors

Most women who develop breast cancer have no risk factors other than simply being a woman and getting older (especially being over 50).

Other risk factors include:
  • Having had breast cancer before
  • Family history of breast cancer (especially in a mother, sister or daughter diagnosed before menopause or if mutations on BRCA1 or BRCA2 genes are present)
  • Family history of ovarian cancer

An above-average exposure to the hormone estrogen, which your body naturally produces, perhaps because you:

  • Have never given birth or gave birth for the first time after age 30
  • Began menstruating at a young age
  • Reached menopause later than average
  • Have taken hormone replacement therapy (estrogen plus progestin)
  • Have dense breast tissue (as shown on a mammogram)
  • Have a history of breast biopsies showing certain breast changes, such as an increased number of abnormal cells that are not cancerous (atypical hyperplasia)
  • Have had radiation treatment to the chest area (for example, to treat Hodgkin lymphoma), especially before age 30

Probability & Trend

One in 9 women is expected to develop breast cancer during her lifetime and one in 28 will die from it.

Breast cancer incidence rose steadily from 1980 to the early 1990s, partly because of increased mammography screening. Breast cancer death rates have declined in every age group since at least the mid 1980s due to significant advances in breast cancer screening and treatment.

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