Understanding Your Risk

Breast cancer is the most common cancer diagnosed in Canadian women. The cause remains unknown but risks which increase your chances of breast cancer have been identified and will vary with each individual. Are you concerned with breast cancer? in CancerCare's Clinical Investigations Office web site, contains a list of risk factors and information about breast cancer prevention trials.

As the most common cancer diagnosed in Canadian women, breast cancer will involve over 21,000 women across Canada this year. What does this mean for an individual woman?

The often quoted statistic: 1 in 9 women will develop breast cancer can be misleading and causes many women to think their risk is higher than it actually is. This number refers to the chance a woman has of developing breast cancer over a lifetime of 90 years. Because many women do not live to 90 years where the incidence is highest, and breast cancer is more common in women over 50 years, generalizing to a lifetime risk may not be the clearest way to indicate a woman's risk. It may be clearer and more useful to look at a woman's risk in relation to her age today as indicated below:

You can see by looking at this table, that even a woman who is 80 years of age only has a 1 in 250 chance of developing breast cancer in the next year. Although this does not change her 1 in 9 lifetime risk, it is a better indicator of the woman's actual risk today.