Survival Benefits of Repeated Breast Cancer Screening

Take-Away Points

• ■ Major Focus: To assess the long-term survival benefits with respect to breast cancer mortality of repeated participation in breast cancer screening mammography.

• ■ Key Results: Patients who developed breast cancer and participated in repeated breast cancer screening saw a larger reduction in hazard of breast cancer death with each successive screening examination when compared with patients who did not participate in any screening.

• ■ Impact: Participation in repeated breast cancer screening confers better survival in patients who develop breast cancer.

The benefits of routine mammographic screening in reducing breast cancer morbidity and mortality have been well established. Mammographic screening of asymptomatic individuals is widely available and currently accepted as standard-of-care practice in most middle- and high-income countries. Updated recommendations from the American College of Radiology suggest that screening mammography should begin at age 40 for average-risk patients and be performed at yearly intervals.

Data from a previous study suggested that participation in two successive mammography screening sessions offered greater survival benefits with respect to breast cancer mortality than participation in only one of the two sessions. In this study, Duffy et al hypothesized that successive participation in scheduled screening examinations prior to breast cancer diagnosis would offer a greater protective effect. The authors examined population screening data in Sweden from over 37 000 patients diagnosed with breast cancer over a 24-year period to determine patient participation in their five most recent scheduled mammographic screening sessions prior to diagnosis. After correcting for self-selection bias, the authors found a 66% reduction in hazard of death due to breast cancer (hazard ratio [HR], 0.34; 95% CI: 0.26, 0.43) for patients who participated in all five of their most recent screenings prior to breast cancer diagnosis when compared with those who did not participate in any of the five recent screenings. Moreover, the authors found increasingly better survival with increasing participation in scheduled screenings with reductions in hazard of death ranging from 13% (HR, 0.87; 95% CI: 0.67, 1.12) for patients who participated in only one of five screening sessions prior to diagnosis to 55% (HR, 0.45; 95% CI: 0.35, 0.58) for patients who participated in four of five screenings prior to diagnosis.

The authors concluded that patients who develop breast cancer have improved survival with increased participation in scheduled mammographic screenings prior to diagnosis.

Highlighted Article

• Duffy SW, Yen AMF, Tabar L, et al. Beneficial effect of repeated participation in breast cancer screening upon survival. J Med Screen 2023:9691413231186686. doi: https://doi.org/10.1177/09691413231186686