3D mammograms could provide significant improvements in cancer detection and decreasing false positives when used in collaboration regular 2D mammograms, according to a new study by a team of Italian and Australian researchers.
The finding, published in The Lancet Oncology, analyzed whether using 2D and 3D screenings together was more accurate at detecting cancers and decreasing false positives than just 2D screenings.
Led by associate professor Nehmat Houssami, at the University of Sydney’s School of Public Health in Australia, the researchers screened 7,292 women with an average age of 58 years in Verona and Trento, Italy. First, their screens were documented using 2D mammograms, and then using a combination of 2D and 3D mammograms.
The investigators found 59 cancers in total in 57 different patients. Approximately two-thirds of the cancers that were found (66%) were detected in both 2D and the combination of 2D and 3D screenings. However, a third (33%) were not seen when only using the 2D – and were only found when using the combination of the 2D and 3D screenings.
These results are the same as a rate of 5.3 cancers per 1000 screens found by 2D alone, and 8.1 cancers found for every 1000 screens by the combination of 2D and 3D screenings.
Earlier studies have looked at the advantages of 3D mammography. However, the current study is the first to draw conclusions about the effectiveness 3D screening in a large sample of women.
Additionally, the researchers found that the combination of 2D and 3D screenings was associated with a decreased number of false positives – when screening finds an unusual abnormality that ends up not being accurate in further testing.
Among all the false positives that happened during the current study, 141 of them happened using 2D screening only, compared with just 73 using the combination of 2D and 3D screenings. Overall, 181 false positives took place at both screen readings – suggesting that this is still a significant problem that needs to be dealt with during breast screening.
According to Professor Houssami:
“Although controversial, mammography screening is the only population-level early detection strategy that has been shown to reduce breast cancer mortality in randomized trials. Irrespective of which side of the mammography screening debate one supports, efforts should be made to investigate methods that enhance the quality of, and hence potential benefit from, mammography screening.
We have shown that integrated 2D and 3D mammography in population breast-cancer screening increases detection of breast cancer and can reduce false-positive recalls depending on the recall strategy. Our results do not warrant an immediate change to breast-screening practice, instead, they show the urgent need for randomised controlled trials of integrated 2D and 3D versus 2D mammography.”
Last year, a study published in JAMA suggested that ultrasound screening or MRI in addition to regular mammography screening actually increases breast cancer detection rates among women.
Expenses related to new technologies like 3D mammograms may become a concern. For instance, a study in JAMA Internal Medicine revealed that medicare is putting out as much money screening for breast cancer as it does treating it. Screening expenses for breast cancer in the Medicare program surpassed over $1 billion per year in the fee-for-service program during 2006 to 2007.
Written by Kelly Fitzgerald