Risk-based breast cancer screening reliable, preferred by women over annual screening, study shows

Breast cancer screening based on individual risk rather than annual screening is safe, effective and preferred by patients, according to the results of a randomized study using data from the Women Informed to Screen Depending On Measures of risk (WISDOM) Study, recently published in Women’s Health.

A team of researchers led by Laura J. Esserman, M.D., MBA, director of the University of California, San Francisco Breast Care Center, compared the effectiveness of risk-based screening (14,212 women) with annual screening (14,160 women). Women aged 40 to 74 from all 50 states, without prior diagnoses of breast cancer, were recruited from September 2016 to February 2023.

A separate, observational cohort was created for women who did not want to be randomized, of whom 89% chose risk-based screening over annual.

“Importantly, women in the highest risk category, assigned to screen every 6 months, had no stage ≥IIB cancers; no overall reduction in biopsies was observed, but the rates for cancer detection, biopsy, and mammograms increased with rising risk in the risk-based group,” Esserman and her team write in the study.

This is important because it means resources can be shifted from low-risk women to high-risk women, improving survival outcomes.

Esserman and her team screened participants by genetic, biological and lifestyle factors, looking specifically for the presence of nine susceptibility genes and calculating a patient’s risk using the polygenic risk score and using the Breast Cancer Surveillance Consortium version 2 model.

All women in the annual group were at least 40 years old because that is the age many health organizations, including the U.S. Preventive Services Task Force, recommend women receive their first mammogram if a patient is of average risk.

The risk-based group was divided into four groups and women were given instructions based on their individual risk level.

1. The group with the highest risk women, who represented 2% of participants and were defined as having at least a 6% 5-year risk of developing breast cancer, should receive mammography and magnetic resonance imaging (MRI), alternating every six months, plus risk-reduction counseling.

2. Elevated-risk women, who represented 8% of participants and were defined as being in the top 2.5% risk percentile by age, should receive an annual mammogram and counseling.

3. Average-risk women, representing 62% of participants, were instructed to receive a biennial mammogram.

4. Low-risk women, who represented 26% of participants, should receive no screening until risk is at least 1.3% or at age 50.

Breast cancer is the second most common cancer in women in the United States and the second leading cause of death in women, behind skin cancer and lung cancer, respectively, according to the American Cancer Society. Approximately 1 in 8 women will be diagnosed with breast cancer in her lifetime. Incidence rates are also on the rise, increasing by approximately 1% each year.

Breast cancer death rates have dropped 44% since 1989, likely due to improved, earlier detection methods and treatment advances. However, today 1 in 43 women still die from breast cancer.

Researchers are currently enrolling participants in the WISDOM 2.0 Study.