Breast Screening Guidelines Summary
This summary also available to download – Ontario Breast Screening Program (OBSP) Guidelines Summary.
Also see: Follow-Up of Abnormal Breast Screens
Screening Average Risk Women Ages 50 to 74 Years
Screening high risk women ages 30 to 69 years
Limitations of Breast Cancer Screening
- Mammography may miss some breast cancers and some cancers develop in the time between screens.
- For every 200 women screened in the Ontario Breast Screening Program, about 17 are referred for further tests and 1 will have breast cancer.
- Not all cancers found at screening can be treated successfully.
- Some breast cancers that are diagnosed with screening may never cause symptoms in a woman during her lifetime (i.e., over-diagnosis). Therefore, some women may have surgery or treatment for a breast cancer that would not have become life-threatening.