3-D breast cancer imaging boosts detection: study

Fewer patients were called back for additional imaging and there was a higher rate of breast cancer detection, when screening extended beyond digital mammography to include 3-D imaging, a new study finds. There may be potential benefits of adding 3-D imaging to current screening programs, the authors say, but more research is needed.

Researchers compared breast cancer screening performance outcomes at 13 academic and nonacademic breast centers, both before and after the introduction of a 3-D breast imaging technique called tomosynthesis. A total of 454,850 examinations were evaluated during the two periods.

When tomosynthesis was introduced, the invasive cancer detection rate increased from 2.9 to 4.1 per 1,000, a relative increase of 41%, according to the findings published June 25 in JAMA. There was also a 29% increased detection rate for all breast cancers.

When both digital mammography and tomosynthesis were used, 11 of the 13 participating cancer centers saw a decrease in recall rate—or proportion of patients who required additional imaging after screening. The relative decrease in the recall rate was 15%, the study found.

“It's the most exciting improvement to mammography that I have seen in my career,” said study co-author Dr. Emily Conant, chief of breast imaging at the Perelman School of Medicine at the University of Pennsylvania. “3-D mammography finds more clinically significant breast cancers earlier, which is the key so that women have more treatment options and ultimately better health outcomes,” she said in a statement.

Of the 281,187 patients screened with digital mammography, 29,726 were recalled and 5,056 biopsies resulted in cancer diagnosis in 1,207 patients. Of the 173,663 screened with the combination of digital mammography and tomosynthesis, 15,541 patients were recalled and 3,285 biopsies resulted in cancer diagnosis in 950 patients.

Authors on the study included physicians and researchers from Caldwell Breast Center of Advocate Lutheran General Hospital, Park Ridge, Ill.; Massachusetts General Hospital, Boston; the TOPS Comprehensive Breast Center, Houston; Solis Women's Health in Dallas; Yale University School of Medicine, New Haven, Conn.; Case Medical Center in Cleveland; and the John C. Lincoln Breast Health and Research Center in Phoenix, among nine other institutions.

Though the findings are promising, the authors note several limitations and items for further study. For example, the lack of a randomized trial design could mean the results are not purely due to the introduction of 3-D imaging. They also say follow-up data were not available to allow evaluation of false-negative results.

“Tomosynthesis is likely an advance over digital mammography for breast cancer screening, but fundamental questions about screening remain, with all available technologies,” said Dr. Etta Pisano of the Medical University of South Carolina and Martin Yaffe of the University of Toronto, in an accompanying editorial. “The continuing controversy surrounding the most effective strategy for deploying the various available technologies continues unabated,” they said, noting that consensus is needed on not only when to screen, but how often and with what tools.

That was the topic of debate in February, when a BMJ study from Canadian researchers concluded annual mammography in women ages 40 to 59 did not reduce breast cancer deaths. The study authors said the rationale for screening by mammography should be urgently reassessed by policymakers.

Breast cancer remains the second-leading cause of cancer deaths in women, exceeded only by lung cancer, according to the American Cancer Society. About 1 in 8, or about 12% of women in the U.S., will develop invasive breast cancer during their lifetime.

Follow Sabriya Rice on Twitter: @MHSRice