Women Aged 40 to 49: Breast Cancer Screening Recommendations

Breast cancer screening in women aged 40 to 49 continues to make headlines. The American Cancer Society estimates that 20 percent of cases of breast cancer occur in women of this age group, with approximately 50,000 new cases of invasive breast cancer diagnosed in American women aged 40 to 49 in 2013. Despite these frightening facts, screening mammography in women aged 40-49 remains highly controversial.

Much of the controversy relates to guidelines published by the United States Preventive Services Task Force (USPSTF) in 2009.  A draft of the updated 2015 guidelines was recently released. Both sets of guidelines recommended against routine screening in women between the ages of 40 and 49. However, it is important to realize that the USPSTF panel did not include a single doctor specializing in breast cancer.  Many doctors whose expertise is in breast cancer diagnosis and treatment, including the Breast Imaging team at UCSF, disagree with the USPSTF recommendations.

Women aged 40 to 49 can develop aggressive, life-threatening breast cancer.  There is data from multiple randomized controlled trials (the most stringent type of scientific trial) that screening mammography saves lives.  In addition, breast cancers found on mammography are often smaller and can be treated with less aggressive surgery and chemotherapy than if they had been found on clinical exam. Waiting for a cancer to grow to a size where it can be felt is dangerous.  

Some groups have proposed using mammography to screen high-risk women only.  However, studies have shown that using this type of risk-based approach to screening misses the vast majority of breast cancers.  This is because the vast majority of women aged 40 to 49 who develop breast cancer do not have any known risk factors. Therefore, we do not support screening for high-risk women only – we recommend all women aged between 40 and 49 years-old undergo annual screening mammography.

Unfortunately, the controversy surrounding this issue results in much patient confusion. In Breast Imaging at UCSF, we try to dispel this confusion by following the evidence-based recommendations of the American College of Radiology and the American Cancer Society – that women begin annual screening mammography at age 40. This approach results in 100,000 more lives saved from breast cancer than if the USPSTF recommendations are followed.

For more information on Women’s Imaging at UCSF, please click here.