printemailclick to share buttonfacebooktwitterlinkedin
Mammograms are still the best way to detect breast cancer early
Posted on 2014/02/13

A recent study on the effectiveness of mammography for breast cancer screening has generated much discussion in the media. 

It’s important for women in Ontario to know that mammography is still the most effective method of screening for breast cancer. 

The report in question was released by the researchers leading the Canadian National Breast Cancer Study, which has been following almost 90,000 women for 25 years. The study’s recent report stated that there was no difference in the number of deaths from breast cancer between women aged 40 to 59 who were screened using mammography and those aged 40 to 59 who were screened by physical examination only.

These findings add to a long-standing debate over mammography for breast cancer screening and demonstrate that the test is not perfect. Mammography may miss some breast cancers or may produce abnormal results, raising the suspicion of cancer, when, in fact, additional imaging and biopsies show there is no cancer. Sometimes mammography finds a cancer that would not have caused harm to a woman or been detected in her lifetime (this is called over-diagnosis). These over-diagnosed women then end up undergoing treatment that provides no benefit.

Unfortunately, there is no clinical technology that can distinguish a tumour that will lead to harm, including death, from one that will not. For this reason, clinicians recommend treating all screen-detected breast cancers.

Because mammography is not a perfect test, Cancer Care Ontario recommends women be made aware of the potential risks of screening. Women should discuss the benefits and harms of screening with their healthcare provider when making a decision about getting screened for breast cancer.

Regular breast cancer screening finds cancers when they are small and less likely to have spread. Therefore, women with screen-detected cancers tend to have more treatment options, a reduced chance of cancer recurrence and an improved chance of survival.

The Ontario Breast Screening Program recommends screening mammography every two years for women aged 50 to 74 years. I want to encourage all women in this age range to speak with their healthcare provider to ensure they are being screened appropriately.

Linda Rabeneck MD MPH FRCPC
Vice President, Prevention and Cancer Control
Cancer Care Ontario

Last modified: Thu, Feb 13, 2014
cancer care ontario | action cancer ontario   620 University Avenue Toronto Ontario, Canada M5G 2L7   Phone: 416.971.9800 Fax: 416.971.6888

Please help improve the quality of our website by answering 10 brief questions in our online survey. Would you like to participate?