Increased Cancer Detection Rate and Variations in the Recall Rate Resulting from Implementation of 3D Digital Breast Tomosynthesis into a Population-based Screening Program

Abstract

Purpose: To compare the recall and cancer detection rates (CDRs) at screening with digital breast tomosynthesis (DBT) with those at screening with two-dimensional (2D) mammography and to evaluate variations in the recall rate (RR) according to patient age, risk factors, and breast density and among individual radiologists at a single U.S. academic medical center.

Materials and methods: This institutional review board-approved, HIPAA-compliant prospective study with a retrospective cohort included 85 852 asymptomatic women who presented for breast cancer screening over a 3-year period beginning in 2011. A DBT unit was introduced into the existing 2D mammography screening program, and patients were assigned to the first available machine. Ten breast-subspecialized radiologists interpreted approximately 90% of the examinations. RRs were calculated overall and according to patient age, breast density, and individual radiologist. CDRs were calculated. Single and multiple mixed-effect logistic regression analyses, χ(2) tests, and Bonferroni correction were utilized, as appropriate.

Results: The study included 5703 (6.6%) DBT examinations and 80 149 (93.4%) 2D mammography examinations. The DBT subgroup contained a higher proportion of patients with risk factors for breast cancer and baseline examinations. DBT was used to detect 54.3% more carcinomas (+1.9 per 1000, P < .0018) than 2D mammography. The RR was 7.51% for 2D mammography and 6.10% for DBT (absolute change, 1.41%; relative change, -18.8%; P < .0001). The DBT subgroup demonstrated a significantly lower RR for patients with extremely or heterogeneously dense breasts and for patients in their 5th and 7th decades.

Conclusion: Implementing DBT into a U.S. breast cancer screening program significantly decreased the screening RR overall and for certain patient subgroups, while significantly increasing the CDR. These findings may encourage more widespread adoption and reimbursement of DBT and facilitate improved patient selection.

Figure 1:

Graph shows adjusted odds ratios for RR according to examination type, family history of breast cancer, personal history of breast cancer, personal history of a breast biopsy with a benign result, and first/baseline mammographic examination. Patients undergoing baseline (first) mammography and patients with a family history of breast cancer were more likely to be recalled.

Figure 2:

Graph shows adjusted odds ratios for RR according to patient age at screening. Age of 70 or greater was the reference condition. Patients younger than 60 years of age were more likely to be recalled.

Figure 3:

Graph shows adjusted odds ratios for RR according to breast density. Predominantly fatty density was the reference condition. Patients with scattered fibroglandular densities, heterogeneously dense breasts, or extremely dense breasts were more likely to be recalled.

Figure 4:

Adjusted odds ratios for RR according to radiologist. Radiologist 1, who interpreted the largest number of studies, was the reference radiologist. Radiologist 2, who interpreted the most DBT studies, was also significantly less likely to recall patients than the other radiologists.