June 25, 2014
Novel Three-Dimensional Imaging Ups Breast Cancer Detection Rate
Rebekah Eliason for redOrbit.com – Your Universe Online
Tomosynthesis is a type of three-dimensional imagery added to 170,000 examinations. Adding this new type of breast imaging technique to digital mammography has been associated with a decrease in the proportion of patients who need to be called back for additional imaging and an increase in cancer detection rate.
Although screening mammography has drawn criticism for large amounts of false-positive results, limited sensitivity and potentially over-diagnosis of clinically insignificant lesions, it has played a vital role in reducing breast cancer mortality.
Tomosynthesis was approved by the US Food and Drug Administration in 2011. It is used in combination with standard digital mammography for breast cancer screening. According to single-institution studies, the addition of tomosynthesis to mammography increases cancer detection and reduces false-positive results.
Sarah M. Friedewald, MD, of Advocate Lutheran General Hospital, Park Ridge, Illinois, and her colleagues performed a study using data from thirteen different centers to determine how mammography combined with tomosynthesis could improve breast screen program performance. For this study, 454,850 examinations were evaluated.
The researchers primarily looked at the measured outcomes of recall rate (proportion of patients requiring additional imaging based on a screening examination result), cancer detection rate, positive predictive value for recall (proportion of patients recalled after screening who were diagnosed as having breast cancer) and positive predictive value for biopsy (proportion of patients undergoing biopsies who were diagnosed as having breast cancer).
"The success of mammography screening in reducing mortality is predicated on the principle of detecting and treating small, asymptomatic cancers before they have metastasized. Accordingly, the preferential increase in invasive cancer detection with addition of tomosynthesis may be of particular value in optimizing patient outcomes from mammography screening," the authors write.
"The association with fewer unnecessary tests and biopsies, with a simultaneous increase in cancer detection rates, would support the potential benefits of tomosynthesis as a tool for screening. However, assessment for a benefit in clinical outcomes is needed."
"As Friedewald et al have indicated, tomosynthesis is likely an advance over digital mammography for breast cancer screening, but fundamental questions about screening remain, with all available technologies," write Etta D. Pisano, MD, of the Medical University of South Carolina, Charleston, and Martin J. Yaffe, PhD, of the University of Toronto.
"Breast cancer remains a major public health problem, with approximately 40,000 U.S. women still dying annually. The continuing controversy surrounding the most effective strategy for deploying the various available technologies continues unabated, and clear consensus is lacking on when to screen, how often, and with what tools, or even which screen-detected cancers could be managed more conservatively. Only an appropriately powered multisite controlled clinical trial of modern technology can answer the remaining questions definitively. The time is now for the National Institutes of Health to fund such a much-needed trial to address many of the remaining issues about breast cancer screening."
This study was published in the June 25 issue of JAMA.