MRI screening may help women with dense breasts

Women with extremely dense breast tissue appear to benefit from MRI screening added to the population-based mammography screening program. As this group has increased breast cancer risk and because cancers are more difficult to detect in the dense fibroglandular tissue, approximately 4800 women were selected to receive a supplemental MRI examination after a regular mammography screening examination. The results of the first round of this DENSE-trial are promising, as published in the New England Journal of Medicine Nov 28th. In every 1000 women with extremely dense breasts 17 breast cancers were detected with MRI. The mammograms of these women were normal.

From the University Medical Center Utrecht, the Netherlands, prof. dr. Carla van Gils, dr. Wouter Veldhuis and prof. dr. Ruud Pijnappel lead the research group, consisting of researchers from eight Dutch hospitals. Katya Duvivier. M.D. en dr. Pim de Graaf are the researchers involved at Amsterdam UMC.

Van Gils: “The first results are encouraging. With a supplemental MRI-scan we detect cancers that were not detected in the regular screening program. We detect them in an earlier stage. As a result, it occurs less frequently that women discover in between screening examinations that they have breast cancer because of signs or symptoms. Later this year we will finish a study where we use the results in a mathematical model to estimate the impact on the longer term. Does the early breast cancer detection with MRI indeed lead to a reduction in breast cancer mortality, and will treatment be less extensive and thus less burdensome? In the end the benefits need to be carefully weighed against the harms, as MRI examination is more expensive, and it requires the injection of contrast agent into the body. MRI will also detect abnormalities that later turn out not to be breast cancer after all. Also, MRI may detect breast cancers that grow so slowly that they would never have caused health problems and therefore are treated unnecessarily. If the long-term benefits weigh against these harms, MRI examination for women with extremely dense breasts is an important step from a ‘one size fits all’ to a ‘tailor-made’ breast cancer screening program.

New research findings are summarized in a short video.