Sarah Moorman, MD  Department of Radiology  Michigan Medicine  

Morbidity of Breast Cancer and Screening Interval: Annual versus Biennial Interview with:

Sarah Moorman, MD  Department of Radiology  Michigan Medicine  

Dr. Moorman

Sarah Moorman, MD
Department of Radiology
Michigan Medicine What is the background for this study?

Response: Professional societies and government agencies have variable recommendations regarding how often women should get a screening mammogram. Breast cancer screening may be recommended annually or biennially. These differing recommendations lead to confusion for both referring physicians and patients.

The goal of our study was to better understand differences between annual and biennial screening. We reviewed clinical outcomes of women undergoing annual or biennial mammographic screening to determine if there is an advantage to annual screening. What are the main findings?

  1. Annual screening resulted in less frequent advanced stage breast cancers compared with biennial screening [annual 48/200 (24%) versus biennial 14/32 (44%), p=0.02].
  2. Annual screening mammography resulted in fewer interval cancers compared with patients undergoing biennial screening [annual 21/200 (11%) versus biennial 12/32 (38%), p<0.001].
  3. Mean cancer size was significantly smaller among patients undergoing annual screening compared with biennial screening (annual 1.4 +2 cm versus biennial 1.8 + 1.6 cm, p=0.04).
  4. When post-menopausal women were analyzed as a sub-group, the findings of less frequent advanced stage breast cancer, fewer interval cancers, and small mean cancer size with annual screening persisted.
  5. Compared with biennial screening, breast cancer diagnosed in the setting of annual screening mammography showed a trend for less frequent axillary lymph node dissection [annual 24/200 (12%), biennial 6/32 (19%)] and less frequent use of chemotherapy [annual 55/200 (28%), biennial 12/32 (38%)]. What should readers take away from your report?

Annual screening mammography was associated with less frequent advanced stage breast cancers, fewer interval cancers, and smaller average tumor size compared with biennial screening. Patients undergoing yearly screening mammograms who were diagnosed with breast cancer had less advanced (lower stage) breast cancers than those undergoing screening mammograms every 2 years.

There were trends toward less frequent axillary lymph node dissection (less extensive surgery) and less frequent use of chemotherapy with annual screening compared with biennial screening.

Our findings add information to allow informed decision-making regarding frequency of breast cancer screening. Screening mammography performed at less than annual frequency resulted in increased morbidity for patients diagnosed with breast cancer.

Disclosures: Drs. Pujara, Neal, Helvie: GE Healthcare (institutional grant, Dr. Maturen: Wolters Kluwer (royalties) 


RSNA 2019 abstract:

Morbidity of Breast Cancer as a Function of Screening Interval: Annual versus Biennial 


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Last Updated on December 6, 2019 by Marie Benz MD FAAD