Digital Mammography Reduces Recall and Biopsy Rates
Population-based screening with full-field digital mammography is associated with lower recall and biopsy rates than screen-film mammography, suggesting that full-field digital mammography may reduce the number of diagnostic workups and biopsies that do not lead to diagnosis of breast cancer, according to a new study by Hofvind et al published online in the journal Radiology.
Previous population-based studies comparing the accuracy of screen-film mammography vs full-field digital mammography have reported conflicting results, and reported recall rates (the rate at which women are called back for additional tests) have varied widely. In addition, past performance evaluations of breast imaging screening technologies do not account for the transition phase of adoption.
Study Details
For this study, data collected from the Norwegian Breast Cancer Screening Program (NBCSP) was used to compare performance measures and outcomes before, during and after the transition from screen-film mammography to full-field digital mammography.
"The program invites women age 50 to 69 years to mammographic screening every 2 years," said Solveig Hofvind, PhD, from the Cancer Registry of Norway and Oslo University College, in Oslo, Norway. "We analyzed performance measures in the program as run in a usual setting."
To examine the effect of transition from screen-film mammography to full-field digital mammography, researchers analyzed the rate of cases, the recall rate, the rate of screen-detected cancer, and the rate of interval cancers.
"The study includes results from women screened with screen-film mammography only, with both screen-film mammography and full-field digital mammography, and with full-field digital mammography only. These combinations make us able to compare early performance measures achieved when using digital mammography in a routine setting, in a proper way," Dr. Hofvind said.
Outcomes
A total of 1,837,360 NBCSP screening exams were performed from 1996 through 2010, with 58.8 years being the average age at the time of screening. The overall recall rate was 3.4% for screen-film mammography and 2.9% for full-field digital mammography. The biopsy rate was 1.4% for screen-film mammography and 1.1% full-field digital mammography.
Both the rate of invasive screening-detected and interval breast cancer remained stable during the transition from screen-film mammography to full-field digital mammography and after full-field digital mammography was firmly established. The positive predictive value of recalled examinations and of biopsy procedures increased from 19.3% and 48.3% to 22.7% and 57.5%, respectively, after adoption of full-field digital mammography.
By studying the transition phase of screening modality, researchers discovered full-field digital mammography implementation led to lower rates of false-positive screening exams and fewer biopsies with benign outcome.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
