Breast cancer is the most common cancer in Canadian women, with one in nine women expected to be diagnosed with it in their lifetime. In 2014, it is estimated that about 9,800 Ontario women will be diagnosed with breast cancer and that 1,900 will die from this disease.
Screening is available for two groups of women
Breast cancer occurs primarily in women 50 to 74 years of age (57% of cases). Most women diagnosed with breast cancer have no family history of the disease.
Less than 1% of women in the general population are estimated to be at high risk for breast cancer. Women are considered to be at high risk for breast cancer and eligible for screening if they have no acute breast symptoms, are 30 to 69 years of age and meet one of the following risk criteria:
Women at high risk have a greater estimated lifetime risk of developing breast cancer (up to 85%) than the general population (10-12%).
Women at high risk develop breast cancer at an earlier age and their breast cancers tend to be more aggressive than breast cancers diagnosed in women at average risk.
Breast cancer screening is the regular examination of a woman's breasts to find breast cancer early. The best screening test for most women is the mammogram. A mammogram takes an X-ray picture of the breast and can find changes in the breast even when they are too small to feel or see. For most women, the mammogram results will be normal.
For women at high risk, screening with breast magnetic resonance imaging (MRI) will be used in addition to mammography (MM)
Women aged 50 to 74 years can call the nearest OBSP screening location to make an appointment (a doctor’s referral is not needed).View map of screening locations
Letters about breast cancer screening are mailed to eligible women ages 50 to 74.
These letters invite eligible women to get screened for breast cancer, remind them when it’s time to get screened again and inform them of their screening test results. The letters encourage women to speak to their healthcare provider about their screening options and to follow-up on their screening test results, if necessary.Learn more about breast cancer screening letters
The visualizations on this page begin by looking at screening rates throughout Ontario. This serves to give an idea of the absolute and relative numbers of people who are overdue for screening, and where they are concentrated.
The later visualizations add context to this data by displaying the incidence and mortality rates of breast cancer, as well as risk factors divided by regions of Ontario.
This visualization shows screening rates divided by region of Ontario. The hexbinplot displays regions of Ontario as equally-sized hexagons, where darker colours indicate higher number of people overdue for screening. The stacked bar chart shows the same data, where the grey values are people who have been screened, coloured bars are overdue for screening, and the total length of the bar shows the number of people eligible for screening. Hover over the bars to display more information.
These graphs display incidence and mortality rates. The hexbinplots show rates from 2010-12 combined, divided by region and age groups. The line graphs indicate changes in rate over a three-year period, divided by age groups.
These graphs show socio-demographic variables and chronic disease risk factors for regions in Ontario. The hexbinplots show the percentage of the population in each region with each risk factor. The heatmaps show the same data as a table, including multiple years when available. To sort the heatmap, click on the rows and columns.