Canadian guidelines recommend against early mammography

The Canadian Task Force on Preventive Health Care has released breast cancer screening guidelines that recommend against screening in women between the ages of 40 and 49.

The guidelines reiterate the task force's 2011 recommendation and are similar to guidelines from the U.S. Preventive Services Task Force.

In a document published December 10 in the Canadian Medical Association Journal, the task force advises the following:

• Women ages 40 to 49 years should not undergo screening, although if women in this age group would like to be screened, they are encouraged to discuss their options with their doctor.
• Women ages 50 to 74 years should be screened every two to three years; however, some women may choose not to be screened if they are concerned about overdiagnosis.
• Women not at high risk for breast cancer should not be screened with MRI, digital breast tomosynthesis, or ultrasound.

"These recommendations reflect the growing importance of shared decision-making between patients and physicians in preventive health screening, especially in situations like this where the balance between potential benefits and harms is uncertain," task force member Dr. Donna Reynolds of the University of Toronto said in a statement released by the journal. "While screening is recommended for women aged 50 to 74, some may choose not to be screened after weighing the benefits and harms with their physicians, and, conversely, some women under age 50 may choose screening."