World Health Matters: Italy – 3D screening detects more cancers in dense breast tissue

by Gary Finnegan: Researchers have found that in over 3,000 Italian women with dense breasts where standard mammograms had not detected any cancer, the addition of tomosynthesis (a form of 3D mammography) or ultrasound scans picked up an extra 24 tumours.

“These findings will have immediate implications for both screening practice and for guiding new research in dense breasts,” said Dr Nehmat Houssami, Professor of Public Health at the University of Sydney, Australia, who was part of the international team that published results of the trial in the Journal of Cincial Oncology.

Dense breast tissue, where there is a high amount of fibrous and glandular tissue in the breast, is common and not abnormal; however, it makes it harder for standard mammography to detect any signs or other abnormalities that could be cancer, and it is also associated with a higher risk of developing breast cancer.

The researchers in Italy and Australia wanted to see whether the addition of ultrasound or tomosynthesis to the standard mammogram during the same visit could improve detection rates.

The Adjunct Screening with Tomosynthesis or Ultrasound in Mammography-negative Dense breasts (ASTOUND) trial recruited asymptomatic women who attend for breast screening at five imaging centres in Italy and who have dense breasts.

Of the 24 extra breast cancers detected during the trial; 12 were detected by both tomosynthesis and ultrasound, one was detected only by tomosynthesis and 11 only by ultrasound.

“These results mean that tomosynthesis detected an additional four breast cancers per 1,000 women screened and ultrasound detected an additional seven breast cancers per 1,000,” said Prof Houssami.

The researchers, led by Dr Alberto Tagliafico, a radiologist and Assistant Professor of Human Anatomy at the University of Genoa, Italy, also found that, although there were an additional 107 false positive recalls, there were no difference in the additional false recall rate between tomosynthesis and ultrasound.

Prof Houssami said: “In this study we are comparing two additional tests to see if they can do better than standard mammograms in finding cancer in women with dense breasts; we have found that ultrasound does better than tomosynthesis, but ultrasound is a separate test, it is time-consuming and, in less experienced hands, it can lead to a lot of false alarms,” he said.

However, Prof Houssami said that tomosynthesis, which is a form of refined mammography, can be carried out as part of the standard 2D mammogram screen, or even instead of it. “Given that tomosynthesis detected more than 50% of the additional breast cancers in these women, the implications are that it has the potential to be the primary mammography screening method without the need for an extra screening procedure.”

The authors said that further research, as well as cost analyses, would be needed before a definitive recommendation could be made.