Landmark Mammography Study Highlights the Importance of Breast Cancer Screening

University of California San Francisco

December 26, 2018

“A landmark mammography study has found that women who receive annual breast cancer screenings will have a lower mortality rate and will benefit more from therapy upon diagnosis of breast cancer. The lead investigator on this study was László Tabár, MD. He and his team analyzed data from the Swedish Cancer Registry from over 52,000 women who either did or did not participate in mammography screening between 1977 to 2015; nearly 40 years. (They also used comparison data from pre-screening years of 1958 to 1976.) Researchers calculated overall annual incidences of breast cancer, breast cancer incidences resulting in mortality after 10 years and incidences resulting in mortality within 11-20 years. Overall, they concluded that “women who chose to participate in an organized breast cancer screening program” had a 60 percent lower mortality risk within 10 years of diagnosis and a 47 percent lower mortality risk within 20 years of diagnosis. The findings of this study were published in November 2018 in Cancer, the official journal of the American Cancer Society.

“Such findings give more reasons why the UC San Francisco Department of Radiology and Biomedical Imaging supports annual mammography screening starting at age 40 to save more lives,” says Bonnie Joe, MD, PhD, chief of Breast Imaging. “A combination of both screening and therapy are essential. Earlier screening leads to more effective therapy.”

To add to this discussion, a second study, presented at the 2018 Radiological Society of North America (RSNA) annual meeting found that women over age 75 should continue to get annual screening mammograms, as there is a high incidence rate of breast cancer amongst this age group. This study, done by Stamatia Destounis, MD, FACR, a radiologist at Elizabeth Wende Breast Care Clinic in Rochester, New York, analyzed data from 763,256 mammography exams over ten years from 2007 to 2017. Back in 2009, the United States Preventive Services Task Force (USPSTF) said that there was not enough data to “assess the benefits and harms of screening mammography in women 75 years and older. Now, the debate continues.

“There is definitely a debate about what age we should stop screening,” says Dr. Joe. “This research from Dr. Destounis considers the overall health of the individual, too. If a woman 75 and older is in good health, then data shows that annual screening is still very important.”