In November 2011, the Canadian Medical Association Journal published the article “Recommendations on screening for breast cancer in average-risk women aged 40 to 74 years.” The Canadian Task Force on Preventive Health Care developed the new recommendations. This group is “an independent panel of clinicians and methodologists with expertise in prevention, primary care, literature synthesis, critical appraisal and the application of evidence to practice and policy.” In other words, they are family doctors, specialists and probably a few statisticians. They are expert at reviewing the results of many studies and figuring out who, when and how to screen for breast cancer. The goal is to find as many breast cancers as early as possible without exposing women to unnecessary testing.
Screening carries both an emotional and financial cost. As part of developing these recommendations, researchers considered whether finding a cancerous tumour was more likely than incorrect diagnosis and treatment. If the chances of discovering breast cancer are relatively low, the new guidelines recommend against screening.
The changes to breast care come from the 2011 recommendations from the Canadian Task Force on Preventative Health Care. Guidelines for breast cancer screening hadn’t been updated since 2001. A decade of research in this field was analyzed, and new recommendations given for breast self-exam, clinical breast exam (done in a doctor’s office), and screening. Screenings include mammography (breast x-ray) and MRI (magnetic resonance imaging). These guidelines are only for women at ‘average’ risk for breast cancer. A woman at average risk:
A woman’s risk of breast cancer increases if she has a first degree relative with the condition. This means a mother, sister or daughter. Having a grandmother, cousin, aunt, or any other relative with breast cancer should not increase your risk.
The new recommendations:
In Canada, about 80 per cent of newly diagnosed breast cancers are in women over age 50. About 28 per cent are in women over 70.
These new recommendations are considered controversial by some healthcare professionals. The Alberta Society of Radiologists, the Canadian Association of Radiologists, the Canadian Breast Cancer Foundation and the American Cancer Society still support annual breast cancer screening beginning at age 40. These medical bodies are concerned that many of the guideline conclusions were made based on moderate and not high quality research evidence.
“Evidence” is graded as high, moderate, low, or very low based on whether more research is likely to change the recommendation.
On the other hand, the U.S. Preventive Services Task Force and National Health Service in the UK agree that routine screening should be done between the ages of 50 to 74, every two years in the US and every three years in the UK.
The first recommendation with respect to mammography says routine screening is not recommended in women aged 40 to 49. In contrast, the 2001 recommendations suggested that women do regular breast self-exams, and have clinical breast exams and mammography every year starting at age 40.
Here are the numbers behind the new recommendation:
(A biopsy is a small amount of breast tissue that is removed for testing). An unnecessary biopsy means that after the biopsy was done the results only show healthy tissue without any disease.
This task force recognized that there is a significant emotional cost associated with false positives and testing that ensures a woman does not have breast cancer.
As well, no evidence showed that self-breast exams or breast exams done in a doctor’s office reduced deaths due to breast cancer. Instead, tests were more likely to result in false positive results.
What does this mean for you? Most importantly, these guidelines are only for routine screening of average risk women. The decision of how to screen, how often to screen and when to start screening ultimately belongs to you and your doctor. By understanding these recommendations and with her doctor’s help, a woman can decide which screening interval is best for her. The new guidelines exist to help make decisions about the process. If you have a specific concern about your breasts or are considered high risk, then the guidelines do not apply to you. Talk with your doctor about your options.
As medical science makes new discoveries, guidelines change. Updates on breast cancer screening guidelines are expected again in 2016.